[Docs] [txt|pdf] [Tracker] [WG] [Email] [Diff1] [Diff2] [Nits]

Versions: 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 RFC 5975

IETF Internet Draft NSIS Working Group                            G. Ash
Internet Draft                                                      AT&T
Intended status: Experimental                                   A. Bader
<draft-ietf-nsis-qspec-23.txt>                                  Ericsson
Expiration Date: July 2010                                    C. Kappler
                                                              deZem GmbH
                                                                 D. Oran
                                                     Cisco Systems, Inc.
                                                        January 14, 2010


                         QoS NSLP QSPEC Template

Status of this Memo

   This Internet-Draft is submitted to IETF in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF), its areas, and its working groups.  Note that
   other groups may also distribute working documents as Internet-
   Drafts.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   The list of current Internet-Drafts can be accessed at
   http://www.ietf.org/ietf/1id-abstracts.txt.

   The list of Internet-Draft Shadow Directories can be accessed at
   http://www.ietf.org/shadow.html.

   This Internet-Draft will expire on July 14, 2010.

Copyright Notice

   Copyright (c) 2010 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents in effect on the date of
   publication of this document (http://trustee.ietf.org/license-info).
   Please review these documents carefully, as they describe your rights
   and restrictions with respect to this document.

Abstract

   The QoS NSLP protocol is used to signal QoS reservations and is
   independent of a specific QoS model (QOSM) such as IntServ or
   DiffServ.  Rather, all information specific to a QOSM is encapsulated
   in a separate object, the QSPEC.  This document defines a template
   for the QSPEC including a number of QSPEC parameters.  The QSPEC
   parameters provide a common language to be re-used in several QOSMs

Ash, et al.         <draft-ietf-nsis-qspec-23.txt>            [Page 1]

Internet Draft          QoS-NSLP QSPEC Template             January 2010


   and thereby aim to ensure the extensibility and interoperability of
   QoS NSLP.  The node initiating the NSIS signaling adds an initiator
   QSPEC, which indicates the QSPEC parameters that must be interpreted
   by the downstream nodes less the reservation fails, thereby ensuring
   the intention of the NSIS initiator is preserved along the signaling
   path.

Table of Contents

   1. Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . 3
   2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . 4
   3. QSPEC Framework . . . . . . . . . . . . . . . . . . . . . . . . 5
      3.1 QoS Models  . . . . . . . . . . . . . . . . . . . . . . . . 6
      3.2 QSPEC Objects . . . . . . . . . . . . . . . . . . . . . . . 7
      3.3 QSPEC Parameters  . . . . . . . . . . . . . . . . . . . . . 9
          3.3.1 Traffic Model Parameter . . . . . . . . . . . . . . . 10
          3.3.2 Constraints Parameters  . . . . . . . . . . . . . . . 12
          3.3.3 Traffic Handling Directives . . . . . . . . . . . . . 13
          3.3.4 Traffic Classifiers . . . . . . . . . . . . . . . . . 14
      3.4 Example of QSPEC Processing . . . . . . . . . . . . . . . . 14
   4. QSPEC Processing & Procedures . . . . . . . . . . . . . . . . . 17
      4.1 Local QSPEC Definition & Processing . . . . . . . . . . . . 18
      4.2 Reservation Success/Failure, QSPEC Error Codes, & INFO_SPEC
          Notification  . . . . . . . . . . . . . . . . . . . . . . . 20
          4.2.1 Reservation Failure & Error E Flag  . . . . . . . . . 21
          4.2.2 QSPEC Parameter Not Supported N Flag  . . . . . . . . 21
          4.2.3 INFO_SPEC Coding of Reservation Outcome . . . . . . . 22
          4.2.4 QNE Generation of a RESPONSE message  . . . . . . . . 22
          4.2.5 Special Case of Local QSPEC . . . . . . . . . . . . . 23
      4.3 QSPEC Procedures  . . . . . . . . . . . . . . . . . . . . . 24
          4.3.1 Two-Way Transactions  . . . . . . . . . . . . . . . . 24
          4.3.2 Three-Way Transactions  . . . . . . . . . . . . . . . 26
          4.3.3 Resource Queries  . . . . . . . . . . . . . . . . . . 28
          4.3.4 Bidirectional Reservations  . . . . . . . . . . . . . 28
          4.3.5 Preemption  . . . . . . . . . . . . . . . . . . . . . 28
      4.4 QSPEC Extensibility . . . . . . . . . . . . . . . . . . . . 29
   5. QSPEC Functional Specification  . . . . . . . . . . . . . . . . 29
      5.1 General QSPEC Formats . . . . . . . . . . . . . . . . . . . 29
          5.1.1 Common Header Format  . . . . . . . . . . . . . . . . 30
          5.1.2 QSPEC Object Header Format  . . . . . . . . . . . . . 31
      5.2 QSPEC Parameter Coding  . . . . . . . . . . . . . . . . . . 32
          5.2.1 <TMOD-1> Parameter  . . . . . . . . . . . . . . . . . 32
          5.2.2 <TMOD-2> Parameter  . . . . . . . . . . . . . . . . . 33
          5.2.3 <Path Latency> Parameter  . . . . . . . . . . . . . . 34
          5.2.4 <Path Jitter> Parameter . . . . . . . . . . . . . . . 35
          5.2.5 <Path PLR> Parameter  . . . . . . . . . . . . . . . . 36
          5.2.6 <Path PER> Parameter  . . . . . . . . . . . . . . . . 37
          5.2.7 <Slack Term> Parameter  . . . . . . . . . . . . . . . 37
          5.2.8 <Preemption Priority> & <Defending Priority>
                Parameters  . . . . . . . . . . . . . . . . . . . . . 38
          5.2.9 <Admission Priority> Parameter  . . . . . . . . . . . 38
          5.2.10 <RPH Priority> Parameter . . . . . . . . . . . . . . 39

Ash, et al.         <draft-ietf-nsis-qspec-23.txt>            [Page 2]

Internet Draft          QoS-NSLP QSPEC Template             January 2010


          5.2.11 <Excess Treatment> Parameter . . . . . . . . . . . . 40
          5.2.12 <PHB Class> Parameter  . . . . . . . . . . . . . . . 42
          5.2.13 <DSTE Class Type> Parameter  . . . . . . . . . . . . 43
          5.2.14 <Y.1541 QoS Class> Parameter . . . . . . . . . . . . 43
   6. Security Considerations . . . . . . . . . . . . . . . . . . . . 45
   7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 45
   8. Acknowledgements  . . . . . . . . . . . . . . . . . . . . . . . 48
   9. Contributors  . . . . . . . . . . . . . . . . . . . . . . . . . 48
   10. Normative References . . . . . . . . . . . . . . . . . . . . . 50
   11. Informative References . . . . . . . . . . . . . . . . . . . . 51
   12. Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . 53
   Appendix A. Mapping of QoS Desired, QoS Available and QoS Reserved
               of NSIS onto AdSpec, TSpec and RSpec of RSVP IntServ . 53
   Appendix B. Example of TMOD Parameter Encoding . . . . . . . . . . 54
   Appendix C. Change History & Open Issues . . . . . . . . . . . . . 55
               C.1 Change History (since Version -14) . . . . . . . . 55
               C.2 Open Issues  . . . . . . . . . . . . . . . . . . . 56

Conventions Used in This Document

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in RFC 2119 [RFC2119].

1. Introduction

   The QoS NSIS signaling layer protocol (NSLP) [QoS-NSLP] is used to
   signal QoS reservations for a data flow, provide forwarding
   resources (QoS) for that flow, and establish and maintain state at
   nodes along the path of the flow.  The design of QoS NSLP is
   conceptually similar to the decoupling between RSVP [RFC2205] and
   the IntServ architecture [RFC2210], where a distinction is made
   between the operation of the signaling protocol and the information
   required for the operation of the Resource Management Function (RMF).
   [QoS-NSLP] describes the signaling protocol, while this document
   describes the RMF-related information carried in the QSPEC (QoS
   Specification) object carried in QoS NSLP messages.

   [QoS-NSLP] defines four QoS NSLP messages - RESERVE, QUERY, RESPONSE,
   and NOTIFY - each of which may carry the QSPEC object, while this
   document describes a template for the QSPEC object.  The QSPEC object
   carries information on traffic descriptions, resources required,
   resources available, and other information required by the RMF.
   Therefore the QSPEC template described in this document is closely
   tied to QoS NSLP and the reader should to be familiar with [QoS-NSLP]
   to fully understand this document.

   A QoS-enabled domain supports a particular QoS model (QOSM), which is
   a method to achieve QoS for a traffic flow.  A QOSM incorporates QoS
   provisioning methods and a QoS architecture, and defines the behavior
   of the RMF that reserves resources for each flow, including inputs
   and outputs.  The QoS NSLP protocol is able to signal QoS

Ash, et al.         <draft-ietf-nsis-qspec-23.txt>            [Page 3]

Internet Draft          QoS-NSLP QSPEC Template             January 2010


   reservations for different QOSMs, wherein all information specific to
   a QOSM is encapsulated in the QSPEC object and only the RMF specific
   to a given QOSM will need to interpret the QSPEC.  Examples of QOSMs
   are IntServ, DiffServ admission control, and those specified in
   [Y.1541-QOSM, CL-QOSM, RMD-QOSM].

   QSPEC parameters include, for example, a mandatory traffic model
   (TMOD) parameter, constraints parameters, such as path latency and
   path jitter, traffic handling directives, such as excess treatment,
   and traffic classifiers such as PHB class.

   QSPEC objects loosely correspond to the TSpec, RSpec and AdSpec
   objects specified in RSVP and may contain, respectively, a
   description of QoS desired, QoS reserved, and QoS available.
   Going beyond RSVP functionality, the QSPEC also allows indicating
   a range of acceptable QoS by defining a QSPEC object denoting
   minimum QoS.  Usage of these QSPEC objects is not bound to particular
   message types thus allowing for flexibility.  A QSPEC object
   collecting information about available resources may travel in any
   QoS NSLP message, for example a QUERY message or a RESERVE message,
   as defined in [QoS-NSLP].  The QSPEC travels in QoS NSLP messages but
   is opaque to the QoS NSLP, and is only interpreted by the RMF.

   Interoperability between QoS NSIS entities (QNEs) in different
   domains is enhanced by the definition of a common set of QSPEC
   parameters.  A QoS NSIS initiator (QNI) initiating the QoS NSLP
   signaling adds an initiator QSPEC object containing parameters
   describing the desired QoS, normally based on the QOSM it supports.
   QSPEC parameters flagged by the QNI must be interpreted by all QNEs
   in the path, else the reservation fails.  In contrast, QSPEC
   parameters not flagged by the QNI may be skipped if not understood.
   Additional QSPEC parameters can be defined by informational
   specification documents, and thereby ensure the extensibility and
   flexibility of QoS NSLP.

   A local QSPEC can be defined in a local domain with the initiator
   QSPEC encapsulated, where the local QSPEC must be functionally
   consistent with the initiator QSPEC in terms of defined source
   traffic and other constraints.  That is, a domain specific local
   QSPEC can be defined and processed in a local domain, which could,
   for example, can enable simpler processing by QNEs within the local
   domain.

   In Section 3.4 an example of QSPEC processing is provided.

2. Terminology

   Initiator QSPEC: The initiator QSPEC is included into
   a QoS NSLP message by the QNI/QNR.  It travels end-to-end to the
   QNR/QNI and is never removed.

   Local QSPEC: A local QSPEC is used in a local domain

Ash, et al.         <draft-ietf-nsis-qspec-23.txt>            [Page 4]

Internet Draft          QoS-NSLP QSPEC Template             January 2010


   and is domain specific.  It encapsulates the initiator QSPEC and is
   removed at the egress of the local domain.

   Minimum QoS: Minimum QoS is a QSPEC object that MAY be supported by
   any QNE.  Together with a description of QoS Desired or QoS
   Available, it allows the QNI to specify a QoS range, i.e. an upper
   and lower bound.  If the QoS Desired cannot be reserved, QNEs are
   going to decrease the reservation until the minimum QoS is hit.  Note
   that the term "minimum" is used generically, since for some
   parameters, such as loss rate and latency, what is specified is the
   maximum acceptable value.

   QNE: QoS NSIS Entity, a node supporting QoS NSLP.

   QNI: QoS NSIS Initiator, a node initiating QoS NSLP signaling.

   QNR: QoS NSIS Receiver, a node terminating QoS NSLP signaling.

   QoS Available: QSPEC object containing parameters describing the
   available resources.  They are used to collect information along a
   reservation path.

   QoS Desired: QSPEC object containing parameters describing the
   desired QoS for which the sender requests reservation.

   QoS Model (QOSM): a method to achieve QoS for a traffic flow, e.g.,
   IntServ Controlled Load; specifies what sub-set of QSPEC QoS
   constraints & traffic handling directives a QNE implementing that
   QOSM is capable of supporting & how resources will be managed by the
   RMF.

   QoS Reserved: QSPEC object containing parameters describing the
   reserved resources and related QoS parameters.

   QSPEC: QSPEC is the object of QoS NSLP containing all QoS-specific
   information.

   QSPEC parameter: Any parameter appearing in a QSPEC; for
   example, traffic model (TMOD), path latency, and excess treatment
   parameters.

   QSPEC Object: Main building blocks containing a QSPEC parameter set
   that is input or output of an RMF operation.

   QSPEC Type: Identifies a particular QOSM used in the QSPEC


   Resource Management Function (RMF): Functions that are related to
   resource management and processing of QSPEC parameters.

3. QSPEC Framework


Ash, et al.         <draft-ietf-nsis-qspec-23.txt>            [Page 5]

Internet Draft          QoS-NSLP QSPEC Template             January 2010


   The overall framework for the QoS NSLP is that [QoS-NSLP] defines QoS
   signaling and semantics, the QSPEC template defines the container and
   semantics for QoS parameters and objects, and informational
   specifications define QoS methods and procedures for using QoS
   signaling and QSPEC parameters/objects within specific QoS
   deployments.  QoS NSLP is a generic QoS signaling protocol that can
   signal for many QOSMs.

3.1 QoS Models

   A QOSM is a method to achieve QoS for a traffic flow, e.g., IntServ
   controlled load [CL-QOSM], resource management with DiffServ
   [RMD-QOSM], and QoS signaling for Y.1541 QoS classes [Y.1541-QOSM].
   A QOSM specifies a set of QSPEC parameters that describe the QoS
   desired and how resources will be managed by the RMF.  The RMF
   implements functions that are related to resource management and
   processes the QSPEC parameters.

   QOSMs affect the operation of the RMF in NSIS-capable nodes, the
   information carried in QSPEC objects, and may under some
   circumstances (e.g. aggregation) cause a separate NSLP session to be
   instantiated by having the RMF as a QNI.  QOSM specifications may
   define RMF triggers that cause the QoS NSLP to run semantics within
   the underlying QoS NSLP signaling state and messaging processing
   rules, as defined in Section 5.2 of [QoS-NSLP].  New QoS NSLP message
   processing rules can only be defined in Standards Track extensions to
   QoS NSLP.  If a QOSM specification defines triggers that deviate
   from existing standard QoS NSLP processing rules (must be standards
   track in that case), the fallback for QNEs not supporting that QOSM
   are the standard QoS NSLP state transition/message processing rules.

   The QOSM specification includes how the requested QoS resources will
   be described and how they will be managed by the RMF.  For this
   purpose, the QOSM specification defines a set of QSPEC parameters it
   uses to describe the desired QoS and resource control in the RMF, and
   it may define additional QSPEC parameters.

   When a QoS NSLP message travels through different domains, it may
   encounter different QOSMs. Since QOSM use different QSPEC parameters
   for describing resources, the QSPEC parameters included by the QNI
   may not be understood in other domains. The QNI therefore can flag
   those QSPEC parameters it considers vital with the M flag. QSPEC
   parameters with the M flag set must be interpreted by the downstream
   QNEs, or the reservation fails.  QSPEC parameters without the M flag
   set should be interpreted by the downstream QNEs, but may be ignored
   if not understood.

   A QOSM specification MUST include the following:
   - role of QNEs, e.g., location, frequency, statefulness, etc.
   - QSPEC definition including QSPEC parameters
   - QSPEC procedures applicable to this QOSM
   - QNE processing rules describing how QSPEC information is treated

Ash, et al.         <draft-ietf-nsis-qspec-23.txt>            [Page 6]

Internet Draft          QoS-NSLP QSPEC Template             January 2010


     and interpreted in the RMF, e.g., admission control, scheduling,
     policy control, QoS parameter accumulation (e.g., delay).
   - at least one bit-level QSPEC example
   - QSPEC parameter behavior for new QSPEC parameters the QOSM
     specification defines
   - define what happens in case of preemption if the default QNI
     behavior (tear down preempted reservation) is not followed (see
     Section 4.3.5)
   A QOSM specification MAY include the following:

   - define additional QOSM-specific error codes, as discussed in
     Section 4.2.3
   - can state which QoS-NSLP options a QOSM wants to use, when
     several options are available for a QOSM (e.g., local QSPEC to
     either a) hide initiator QSPEC within a local domain message, or
     b) encapsulate initiator QSPEC).

   QOSMs are free, subject to IANA registration and review rules, to
   extend QSPECs by adding parameters of any of the kinds supported by
   the standard QSPEC.  This includes traffic description parameters,
   constraint parameters and traffic handling directives. QOSMs are not
   permitted, however, to reinterpret or redefine the standard QSPEC
   parameters specified in this document.  Note that signaling
   functionality is only defined by the QoS NSLP document [QoS-NSLP] and
   not by this document or by QOSM specification documents.

3.2 QSPEC Objects

   The QSPEC is the object of QoS NSLP containing QSPEC objects and
   parameters.  QSPEC objects are the main building blocks of the QSPEC
   parameter set that is input or output of an RMF operation.  QSPEC
   parameters are the parameters appearing in a QSPEC, which must
   include the traffic model parameter (TMOD), and may optionally
   include constraints (e.g., path latency), traffic handling directives
   (e.g., excess treatment), and traffic classifiers (e.g., PHB class).
   The RMF implements functions that are related to resource management
   and processes the QSPEC parameters.

   The QSPEC consists of a QSPEC version number and QSPEC objects.  IANA
   assigns a new QSPEC version number when the current version is
   deprecated or deleted (as required by a specification).  Note that a
   new QSPEC version number is not needed when new QSPEC parameters are
   specified.  Later QSPEC versions MUST be backward compatible with
   earlier QSPEC versions.  That is, a version n+1 device must support
   QSPEC version n (or earlier).  On the other hand, if a QSPEC version
   n (or earlier) device receives an NSLP message specifying QSPEC
   version n+1, then the version n device responds with an 'Incompatible
   QSPEC' error code (0x0f) response, as discussed in Section 4.2.3,
   allowing the QNE that sent the NSLP message to retry with a lower
   QSPEC version.

   This document provides a template for the QSPEC in order to promote

Ash, et al.         <draft-ietf-nsis-qspec-23.txt>            [Page 7]

Internet Draft          QoS-NSLP QSPEC Template             January 2010


   interoperability between QOSMs.  Figure 1 illustrates how the QSPEC
   is composed of up to four QSPEC objects, namely QoS Desired, QoS
   Available, QoS Reserved and Minimum QoS.  Each of these QSPEC objects
   consists of a number of QSPEC parameters.  A given QSPEC may contain
   only a subset of the QSPEC objects, e.g. QoS Desired.  The QSPEC
   objects QoS Desired, QoS Available and QoS Reserved MUST be supported
   by QNEs.  Minimum QoS MAY be supported.

   +---------------------------------------+
   |            QSPEC Objects              |
   +---------------------------------------+

   \________________ ______________________/
                    V
   +----------+----------+---------+-------+
   |QoS Desir.|QoS Avail.|QoS Rsrv.|Min QoS|
   +----------+----------+---------+-------+

   \____ ____/\___ _____/\___ ____/\__ ___/
        V         V          V        V

   +-------------+...     +-------------+...
   |QSPEC Para. 1|        |QSPEC Para. n|
   +-------------+...     +-------------+...

        Figure 1: Structure of the QSPEC

   The QoS Desired Object describe the resources the QNI desires to
   reserve and hence this is a read-only QSPEC object in that the QSPEC
   parameters carried in the object may not be overwritten.  QoS Desired
   is always included in a RESERVE message (see [QoS-NSLP] for
   descriptions of the QoS NSLP RESERVE, QUERY, RESPONSE, and NOTIFY
   messages).

   The QoS Available Object travels in a RESERVE or QUERY message and
   collects information on the resources currently available on the
   path.  Hence QoS Available in this case is a read-write object, which
   means the QSPEC parameters contained in QoS Available may be updated,
   but they cannot be deleted).  Each QNE MUST inspect all parameters of
   this QSPEC object, and if resources available to this QNE are less
   than what a particular parameter says currently, the QNE MUST adapt
   this parameter accordingly.  Hence when the message arrives at the
   recipient of the message, <QoS Available> reflects the bottleneck of
   the resources currently available on a path.  It can be used in a
   QUERY message, for example, to collect the available resources along
   a data path.

   When QoS Available travels in a RESPONSE message, it in fact just
   transports the result of a previous measurement performed by a
   RESERVE or QUERY message back to the initiator.  Therefore in this
   case, QoS Available is read-only.


Ash, et al.         <draft-ietf-nsis-qspec-23.txt>            [Page 8]

Internet Draft          QoS-NSLP QSPEC Template             January 2010


   QoS Reserved reflects the resources that were reserved. It is a
   read-only object.

   Minimum QoS does not have an equivalent in RSVP.  It allows the QNI
   to define a range of acceptable QoS levels by including both the
   desired QoS value and the minimum acceptable QoS in the same message.
   Note that the term "minimum" is used generically, since for some
   parameters, such as loss rate and latency, what is specified is the
   maximum acceptable value.  Parameters cannot be overwritten in this
   QSPEC object.  The desired QoS is included with a QoS Desired and/or
   a QoS Available QSPEC object seeded to the desired QoS value.  The
   minimum acceptable QoS value MAY be coded in the Minimum QoS QSPEC
   object.  As the message travels towards the QNR, QoS Available is
   updated by QNEs on the path.  If its value drops below the value of
   Minimum QoS the reservation fails and is aborted.  When this method
   is employed, the QNR SHOULD signal back to the QNI the value of QoS
   Available attained in the end, because the reservation MAY need to be
   adapted accordingly.

   Note that the relationship of QSPEC objects to RSVP objects is
   covered in Appendix A.

3.3 QSPEC Parameters

   QSPEC parameters provide a common language for building QSPEC
   objects.  This document defines a number of QSPEC parameters,
   additional parameters may be defined in separate QOSM specification
   documents.  For example, QSPEC parameters are defined in [RMD-QOSM]
   and [Y.1541-QOSM].

   One QSPEC parameter, <TMOD>, is special.  It provides a description
   of the traffic for which resources are reserved.  This parameter must
   be included by the QNI and it must be interpreted by all QNEs.  All
   other QSPEC parameters are populated by a QNI if they are applicable
   to the underlying QoS desired.  For these QSPEC parameters, the QNI
   sets the M flag if they must be interpreted by downstream QNEs.  If
   QNEs cannot interpret the parameter the reservation fails.  QSPEC
   parameters populated by a QNI without the M flag set should be
   interpreted by downstream QNEs, but may be ignored if not understood.

   In this document the term 'interpret' means, in relation to RMF
   processing of QSPEC parameters, that the RMF processes the QSPEC
   parameter according to the commonly accepted normative procedures
   specified by references given for each QSPEC parameter.  Note that a
   QNE need only interpret a QSPEC parameter if it is populated in the
   QSPEC object by the QNI; if not populated in the QSPEC, the QNE does
   not interpret it of course.

   Note that when an ingress QNE in a local domain defines a local QSPEC
   and encapsulates the initiator QSPEC, the QNEs in the interior local
   domain need only process the local QSPEC and can ignore the initiator
   (encapsulated) QSPEC.  However, edge QNEs in the local domain indeed

Ash, et al.         <draft-ietf-nsis-qspec-23.txt>           [Page 9]

Internet Draft          QoS-NSLP QSPEC Template             January 2010


   must interpret the QSPEC parameters populated in the initiator QSPEC
   with the M flag set and should interpret QSPEC parameters populated
   in the initiator QSPEC without the M flag set

   As described in the previous section, QoS parameters may be
   overwritten depending on which QSPEC object, and which message, they
   appear in.

3.3.1 Traffic Model Parameter

   The <Traffic Model> (TMOD) parameter is mandatory for the QNI to
   include in the initiator QSPEC and mandatory for downstream QNEs to
   interpret.  The traffic description specified by the TMOD parameter
   is a container consisting of 4 sub-parameters [RFC2212]:

   o rate (r) specified in octets per second
   o bucket size (b) specified in octets
   o peak rate (p) specified in octets per second
   o minimum policed unit (m) specified in octets
   o maximum packet size (MPS) specified in octets

   The TMOD parameter takes the form of a token bucket of rate (r) and
   bucket size (b), plus a peak rate (p), minimum policed unit (m), and
   maximum packet size (MPS).

   Both b and r MUST be positive.  The rate, r, is measured in octets of
   IP packets per second, and can range from 1 octet per second to as
   large as 40 teraoctets per second.  The bucket depth, b, is also
   measured in octets and can range from 1 octet to 250 gigaoctets.  The
   peak rate, p, is measured in octets of IP packets per second and has
   the same range and suggested representation as the bucket rate.

   The peak rate is the maximum rate at which the source and any
   reshaping (defined below) may inject bursts of traffic into the
   network.  More precisely, it is a requirement that for all time
   periods the amount of data sent cannot exceed MPS+pT where MPS is the
   maximum packet size and T is the length of the time period.
   Furthermore, p MUST be greater than or equal to the token bucket
   rate, r.  If the peak rate is unknown or unspecified, then p MUST be
   set to infinity.

   The minimum policed unit, m, is an integer measured in octets.  All
   IP packets less than size m will be counted, when policed and tested
   for conformance to the TMOD, as being of size m.

   The maximum packet size, MPS, is the biggest packet that will conform
   to the traffic specification; it is also measured in octets.  The
   flow MUST be rejected if the requested maximum packet size is larger
   than the MTU of the link.  Both m and MPS MUST be positive, and m
   MUST be less than or equal to MPS.

   Policing compares arriving traffic against the TMOD parameters at the

Ash, et al.         <draft-ietf-nsis-qspec-23.txt>           [Page 10]

Internet Draft          QoS-NSLP QSPEC Template             January 2010


   edge of the network.  Traffic is policed to ensure it conforms to the
   token bucket.  Reshaping attempts to restore (possibly distorted)
   traffic's shape to conform to the TMOD parameters, and the fact that
   traffic is in violation of the TMOD is discovered because the
   reshaping fails (the reshaping buffer overflows).

   The token bucket and peak rate parameters require that traffic MUST
   obey the rule that over all time periods, the amount of data sent
   cannot exceed MPS+min[pT, rT+b-MPS], where r and b are the token
   bucket parameters, MPS is the maximum packet size, and T is the
   length of the time period (note that when p is infinite this
   reduces to the standard token bucket requirement).  For the
   purposes of this accounting, links MUST count packets that are
   smaller than the minimum policing unit to be of size m.  Packets
   that arrive at an element and cause a violation of the the
   MPS+min[pT, rT+b-MPS] bound are considered non-conformant.

   All 5 of the sub-parameters MUST be included in the TMOD parameter.
   The TMOD parameter can be set to describe the traffic source.  If,
   for example, TMOD is set to specify bandwidth only, then set r = peak
   rate = p, b = large, m = large.  As another example if TMOD is set
   for TCP traffic, then set r = average rate, b = large, p = large.

   When the 5 TMOD sub-parameters are included in QoS Available, they
   provide information, for example, about the TMOD resources available
   along the path followed by a data flow.  The value of TMOD at a QNE
   is an estimate of the TMOD resources the QNE has available for
   packets following the path up to the next QNE, including its outgoing
   link, if this link exists.  Furthermore, the QNI MUST account for the
   resources of the ingress link, if this link exists.  Computation of
   the value of this parameter SHOULD take into account all information
   available to the QNE about the path, taking into consideration
   administrative and policy controls, as well as physical resources.

   The output composed value is the minimum of the QNE's value and the
   input composed value for r, b, p, and MPS, and the maximum of the
   QNE's value and the input composed value for m.  This quantity,
   when composed end-to-end, informs the QNR (or QNI in a RESPONSE
   message) of the minimal TMOD resources along the path from QNI to
   QNR.

   Two TMOD parameters are defined in Section 5, <TMOD-1> and <TMOD-2>,
   where the second (<TMOD-2>) parameter is specified as could be needed
   to support some DiffServ applications.  For example, it is typically
   assumed that DiffServ EF traffic is shaped at the ingress by a single
   rate token bucket.  Therefore, a single TMOD parameter is sufficient
   to signal DiffServ EF traffic.  However, for DiffServ AF traffic two
   sets of token bucket parameters are needed, one token bucket for the
   average traffic and one token bucket for the burst traffic.
   [RFC2697] defines a Single Rate Three Color Marker (srTCM), which
   meters a traffic stream and marks its packets according to three
   traffic parameters, Committed Information Rate (CIR), Committed Burst

Ash, et al.         <draft-ietf-nsis-qspec-23.txt>           [Page 11]

Internet Draft          QoS-NSLP QSPEC Template             January 2010


   Size (CBS), and Excess Burst Size (EBS), to be either green, yellow,
   or red.  A packet is marked green if it does not exceed the CBS,
   yellow if it does exceed the CBS, but not the EBS, and red otherwise.
   [RFC2697] defines specific procedures using two token buckets that
   run at the same rate.  Therefore 2 TMOD parameters are sufficient to
   distinguish among 3 levels of drop precedence.  An example is also
   described in the Appendix to [RFC2597].

3.3.2 Constraints Parameters

   <Path Latency>, <Path Jitter>, <Path PLR>, and <Path PER> are QSPEC
   parameters describing the desired path latency, path jitter, packet
   loss ratio, and path bit error rate respectively.  Since these
   parameters are cumulative, an individual QNE cannot decide whether
   the desired path latency, etc., is available, and hence they cannot
   decide whether a reservation fails.  Rather, when these parameters
   are included in <Desired QoS>, the QNI SHOULD also include
   corresponding parameters in a QoS Available QSPEC object in order to
   facilitate collecting this information.

   The <Path Latency> parameter accumulates the latency of the packet
   forwarding process associated with each QNE, where the latency is
   defined to be the mean packet delay, measured in microseconds, added
   by each QNE.  This delay results from the combination of link
   propagation delay, packet processing, and queueing.  Each QNE MUST
   add the propagation delay of its outgoing link, if this link exists.
   Furthermore, the QNI SHOULD add the propagation delay of the ingress
   link, if this link exists.   The composition rule for the <Path
   Latency> parameter is summation with a clamp of (2**32) - 1 on the
   maximum value.  This quantity, when composed end-to-end, informs the
   QNR (or QNI in a RESPONSE message) of the minimal packet delay along
   the path from QNI to QNR.  The purpose of this parameter is to
   provide a minimum path latency for use with services which provide
   estimates or bounds on additional path delay [RFC2212].

   The <Path Jitter> parameter accumulates the jitter of the packet
   forwarding process associated with each QNE, where the jitter is
   defined to be the nominal jitter, measured in microseconds, added by
   each QNE.  IP packet jitter, or delay variation, is defined in
   [RFC3393], Section 3.4 (Type-P-One-way-ipdv), and where the selection
   function includes the packet with minimum delay such that the
   distribution is equivalent to 2-point delay variation in [Y.1540].
   The suggested evaluation interval is 1 minute.  This jitter results
   from packet processing limitations, and includes any variable queuing
   delay which may be present.  Each QNE MUST add the jitter of its
   outgoing link, if this link exists.  Furthermore, the QNI SHOULD add
   the jitter of the ingress link, if this link exists.  The composition
   method for the <Path Jitter> parameter is the combination of several
   statistics describing the delay variation distribution with a clamp
   on the maximum value (note that the methods of accumulation and
   estimation of nominal QNE jitter are specified in clause 8 of
   [Y.1541]).  This quantity, when composed end-to-end, informs the QNR

Ash, et al.         <draft-ietf-nsis-qspec-23.txt>           [Page 12]

Internet Draft          QoS-NSLP QSPEC Template             January 2010


   (or QNI in a RESPONSE message) of the nominal packet jitter along the
   path from QNI to QNR.  The purpose of this parameter is to provide a
   nominal path jitter for use with services that provide estimates or
   bounds on additional path delay [RFC2212].

   The <Path PLR> parameter is the unit-less ratio of total lost IP
   packets to total transmitted IP packets.   <Path PLR> accumulates the
   packet loss ratio (PLR) of the packet forwarding process associated
   with each QNE, where the PLR is defined to be the PLR added by each
   QNE.  Each QNE MUST add the PLR of its outgoing link, if this link
   exists.  Furthermore, the QNI MUST add the PLR of the ingress link,
   if this link exists.  The composition rule for the <Path PLR>
   parameter is summation with a clamp on the maximum value (this
   assumes sufficiently low PLR values such that summation error is not
   significant, however a more accurate composition function is
   specified in clause 8 of [Y.1541]).  This quantity, when composed
   end-to-end, informs the QNR (or QNI in a RESPONSE message) of the
   minimal packet PLR along the path from QNI to QNR.

   Packet error ratio [Y.1540, Y.1541] is the unit-less ratio of total
   errored IP packet outcomes to the total of successful IP packet
   transfer outcomes plus errored IP packet outcomes in a population of
   interest, with a resolution of at least 10^-9.  If lesser resolution
   is available in a value, the unused digits MUST be set to zero.  Note
   that the number of errored packets observed is directly related to
   the confidence in the result.  The <Path PER> parameter accumulates
   the packet error ratio (PER) of the packet forwarding process
   associated with each QNE, where the PER is defined to be the PER
   added by each QNE.  Each QNE MUST add the PER of its outgoing link,
   if this link exists.  Furthermore, the QNI SHOULD add the PER of the
   ingress link, if this link exists.  The composition rule for the
   <Path PER> parameter is summation with a clamp on the maximum value
   (this assumes sufficiently low PER values such that summation error
   is not significant, however a more accurate composition function is
   specified in clause 8 of [Y.1541]).  This quantity, when composed
   end-to-end, informs the QNR (or QNI in a RESPONSE message) of the
   minimal packet PER along the path from QNI to QNR.

   The slack term parameter is the difference between desired delay and
   delay obtained by using bandwidth reservation, and which is used to
   reduce the resource reservation for a flow [RFC2212].

3.3.3 Traffic Handling Directives

   An application MAY like to reserve resources for packets and also
   specify a specific traffic handling behavior, such as <Excess
   Treatment>.  In addition, as discussed in Section 3.1, an application
   MAY like to define RMF triggers that cause the QoS NSLP to run
   semantics within the underlying QoS NSLP signaling state / messaging
   processing rules, as defined in Section 5.2 of [QoS-NSLP].  Note,
   however, that new QoS NSLP message processing rules can only be
   defined in Standards Track extensions to the QoS NSLP.  As with

Ash, et al.         <draft-ietf-nsis-qspec-23.txt>           [Page 13]

Internet Draft          QoS-NSLP QSPEC Template             January 2010


   constraints parameters and other QSPEC parameters,
   traffic-handling-directives parameters may be defined in QOSM
   specifications in order to provide support for QOSM-specific resource
   management functions.  Such QOSM-specific parameters are already
   defined, for example, in [RMD-QOSM], [CL-QOSM] and [Y.1541-QOSM].
   Generally, a traffic-handling-directives parameters is expected to be
   set by the QNI in <QoS Desired>, and to not be included in
   <QoS Available>. If such a parameter is included in <QoS Available>,
   QNEs may change their value.

   The <Preemption Priority> parameter is the priority of the new flow
   compared with the <Defending Priority> of previously admitted flows.
   Once a flow is admitted, the preemption priority becomes irrelevant.
   The <Defending Priority> parameter is used to compare with the
   preemption priority of new flows.  For any specific flow, its
   preemption priority MUST always be less than or equal to the
   defending priority.  <Admission Priority> and <RPH Priority> provide
   an essential way to differentiate flows for emergency services, ETS,
   E911, etc., and assign them a higher admission priority than normal
   priority flows and best-effort priority flows.

   The <Excess Treatment> parameter describes how the QNE will process
   out-of-profile traffic.  Excess traffic MAY be dropped, shaped and/or
   remarked.

3.3.4 Traffic Classifiers

   An application MAY like to reserve resources for packets with a
   particular DiffServ per-hop behavior (PHB) [RFC2475].  Note that PHB
   class is normally set by a downstream QNE to tell the QNI how to mark
   traffic to ensure treatment committed by admission control, however,
   setting of the parameter by the QNI is not precluded.  An application
   MAY like to reserve resources for packets with a particular QoS
   class, e.g. Y.1541 QoS class [Y.1541] or DiffServ-aware MPLS traffic
   engineering (DSTE) class type [RFC3564, RFC4124].  These parameters
   are useful in various QOSMs, e.g., [RMD-QOSM], [Y.1541-QOSM], and
   other QOSMs yet to be defined (e.g., DSTE-QOSM).  This is intended to
   provide guidelines to QOSMs on how to encode these parameters; use of
   the PHB class parameter is illustrated in the example in the
   following section.

3.4 Example of QSPEC Processing

   This section illustrates the operation and use of the QSPEC within
   the NSLP.  The example configuration in shown in Figure 2.

Ash, et al.         <draft-ietf-nsis-qspec-23.txt>           [Page 14]

Internet Draft          QoS-NSLP QSPEC Template             January 2010


+----------+      /-------\       /--------\       /--------\
| Laptop   |     |   Home  |     |  Cable   |     | DiffServ |
| Computer |-----| Network |-----| Network  |-----| Network  |----+
+----------+     | No QOSM |     |DQOS QOSM |     | RMD QOSM |    |
                  \-------/       \--------/       \--------/     |
                                                                  |
                  +-----------------------------------------------+
                  |
                  |    /--------\      +----------+
                  |   |  "X"G    |     | Handheld |
                  +---| Wireless |-----|  Device  |
                      | XG QOSM  |     +----------+
                       \--------/

      Figure 2: Example Configuration to Illustrate QoS-NSLP/QSPEC
                Operation

   In this configuration, a laptop computer and a handheld wireless
   device are the endpoints for some application that has QoS
   requirements.  Assume initially that the two endpoints are stationary
   during the application session, later we consider mobile endpoints.
   For this session, the laptop computer is connected to a home network
   that has no QoS support.  The home network is connected to a
   CableLabs-type cable access network with dynamic QoS (DQOS) support,
   such as specified in the [DQOS] for cable access networks.  That
   network is connected to a DiffServ core network that uses the RMD
   QOSM [RMD-QOSM].  On the other side of the DiffServ core is a
   wireless access network built on generation "X" technology with QoS
   support as defined by generation "X".  And finally the handheld
   endpoint is connected to the wireless access network.

   We assume that the Laptop is the QNI and handheld device is the QNR.
   The QNI will signal an initiator QSPEC object to achieve the QoS
   desired on the path.

   The QNI sets QoS Desired, QoS Available and possibly Minimum
   QoS QSPEC objects in the initiator QSPEC, and initializes QoS
   Available to QoS Desired.  Each QNE on the path reads and
   interprets those parameters in the initiator QSPEC and checks to see
   if QoS Available resources can be reserved.  If not, the QNE reduces
   the respective parameter values in QoS Available and reserves these
   values.  The minimum parameter values are given in Minimum QoS, if
   populated, otherwise zero if Minimum QoS is not included.  If one or
   more parameters in QoS Available fails to satisfy the corresponding
   minimum values in Minimum QoS, the QNE generates a RESPONSE message
   to the QNI and the reservation is aborted.  Otherwise, the QNR
   generates a RESPONSE to the QNI with the QoS Available for the
   reservation.  If a QNE cannot reserve QoS Desired resources, the
   reservation fails.

   The QNI populates QSPEC parameters to ensure correct treatment of its
   traffic in domains down the path.  Let us assume the QNI wants to

Ash, et al.         <draft-ietf-nsis-qspec-23.txt>           [Page 15]

Internet Draft          QoS-NSLP QSPEC Template             January 2010


   achieve IntServ-Controlled Load-like QoS guarantees, and also is
   interested in what path latency it can achieve.  Additionally, to
   ensure correct treatment further down the path, the QNI includes <PHB
   Class> in <QoS Desired>.  The QNI therefore includes in the QSPEC

   QoS Desired = <TMOD> <PHB Class>
   QoS Available = <TMOD> <Path Latency>

   Since <Path Latency> and <QoS Class> are not vital parameters from
   the QNI's perspective, it does not raise their M flags.

   There are three possibilities when a RESERVE message is received at a
   QNE at a domain border (we illustrate these possibilities in the
   example):

   - the QNE just leaves the QSPEC as-is.

   - the QNE can add a local QSPEC and encapsulate the initiator QSPEC
     (see discussion in Section 4.1; this is new in QoS NSLP, RSVP does
     not do this).

   - the QNE can 'hide' the initiator RESERVE message so that only the
     edge QNE processes the initiator RESERVE message, which then
     bypasses intermediate nodes between the edges of the domain, and
     issues its own local RESERVE message (see Section 3.3.1 of
     [QoS-NSLP]).  For this new local RESERVE message, the QNE acts as
     the QNI, and the QSPEC in the domain is an initiator QSPEC.  A
     similar procedure is also used by RSVP in making aggregate
     reservations, in which case there is not a new intra-domain
     (aggregate) RESERVE for each newly arriving interdomain (per-flow)
     RESERVE, but the aggregate reservation is updated by the border
     QNE (QNI) as need be.  This is also how RMD works [RMD-QOSM].

   For example, at the RMD domain, a local RESERVE with its own RMD
   initiator QSPEC corresponding to the RMD-QOSM is generated based on
   the original initiator QSPEC according to the procedures described in
   Section 4.5 of [QoS-NSLP] and in [RMD-QOSM].  The ingress QNE to the
   RMD domain maps the TMOD parameters contained in the original
   initiator QSPEC into the equivalent TMOD parameter representing only
   the peak bandwidth in the local QSPEC.  The local RMD QSPEC for
   example also needs <PHB Class>, which in this case was provided by
   the QNI.

   Furthermore, the node at the egress to the RMD domain updates QoS
   Available on behalf of the entire RMD domain if it can.  If it
   cannot (since the M flag is not set for <Path Latency>) it raises the
   parameter-specific, 'not-supported' flag, warning the QNR that the
   final latency value in QoS Available is imprecise.

   In the XG domain, the initiator QSPEC is translated into a local
   QSPEC using a similar procedure as described above.  The local QSPEC
   becomes the current QSPEC used within the XG domain, and the

Ash, et al.         <draft-ietf-nsis-qspec-23.txt>           [Page 16]

Internet Draft          QoS-NSLP QSPEC Template             January 2010


   initiator QSPEC is encapsulated.  This saves the QNEs within the XG
   domain the trouble of re-translating the initiator QSPEC, and
   simplifies processing in the local domain.  At the egress edge of the
   XG domain, the translated local QSPEC is removed, and the initiator
   QSPEC returns to the number one position.

   If the reservation was successful, eventually the RESERVE request
   arrives at the QNR (otherwise the QNE at which the reservation failed
   would have aborted the RESERVE and sent an error RESPONSE back to the
   QNI).  If the RII was included in the QoS NSLP message, the QNR
   generates a positive RESPONSE with QSPEC objects QoS Reserved and
   QoS Available.  The parameters appearing in QoS Reserved are the
   same as in QoS Desired, with values copied from QoS Available.
   Hence, the QNR includes the following QSPEC objects in the RESPONSE:

   QoS Reserved = <TMOD> <PHB Class>
   QoS Available = <TMOD> <Path Latency>

   If the handheld device on the right of Figure 2 is mobile, and moves
   through different "XG" wireless networks, then the QoS might change
   on the path since different XG wireless networks might support
   different QOSMs.  As a result, QoS NSLP/QSPEC processing will have to
   renegotiate the QoS Available on the path.  From a QSPEC
   perspective, this is like a new reservation on the new section of the
   path and is basically the same as any other rerouting event - to the
   QNEs on the new path it looks like a new reservation.  That is, in
   this mobile scenario, the new segment may support a different QOSM

   than the old segment, and the QNI would now signal a new reservation
   (explicitly, or implicitly with the next refreshing RESERVE message)
   to account for the different QOSM in the XG wireless domain.  Further
   details on rerouting are specified in [QoS-NSLP].

   For bit-level examples of QSPECs see the documents specifying QOSMs
   [CL-QOSM, Y.1541-QOSM, RMD-QOSM].

4. QSPEC Processing & Procedures

   Three flags are used in QSPEC processing, the M flag, E flag, and N
   flag, which are explained in this section.  The QNI sets the M flag
   for each QSPEC parameter it populates that MUST be interpreted by
   downstream QNEs.  If a QNE does not support parameter it sets the N
   flag and fails the reservation.  If the QNE supports the parameter
   but cannot meet the resources requested by the parameter, it sets the
   E flag and fails the reservation.

   If the M flag is not set, the downstream QNE SHOULD interpret the
   parameter.  If the QNE does not support the parameter it sets the
   N flag and forwards the reservation.  If the QNE supports the
   parameter but cannot meet the resources requested by the parameter,
   it sets the E flag and fails the reservation.


Ash, et al.         <draft-ietf-nsis-qspec-23.txt>           [Page 17]

Internet Draft          QoS-NSLP QSPEC Template             January 2010


4.1 Local QSPEC Definition & Processing

   A QNE at the edge of a local domain may either a) translate the
   initiator QSPEC into a local QSPEC and encapsulate the initiator
   QSPEC in the RESERVE message, or b) 'hiding' the initiator QSPEC
   through the local domain and reserve resources by generating a new
   RESERVE message through the local domain containing the local QSPEC.
   In either case the initiator QSPEC parameters are interpreted at the
   local domain edges.

   A local QSPEC may allow a simpler control plane in a local domain.
   The edge nodes in the local domain must interpret the initiator
   QSPEC parameters.  They can either initiate a parallel session with
   local QSPEC or define a local QSPEC and encapsulate the initiator
   QSPEC, as illustrated in Figure 3.  The Initiator/Local QSPEC bit
   identifies whether the QSPEC is an initiator QSPEC or a local QSPEC.
   The QSPEC Type indicates, for example, that the initiator of local
   QSPEC uses to a certain QOSM, e.g., CL-QSPEC Type.  It may be
   useful for the QNI to signal a QSPEC Type based on some QOSM (which
   will necessarily entail populating certain QOSM-related parameters)
   so that a downstream  QNE can chose amongst various QOSM-related
   processes it might have.  That is, the QNI populates the QSPEC Type,
   e.g., CL-QSPEC Type and sets the Initiator/Local QSPEC bit to
   'Initiator'.  A local QNE can decide, for whatever reasons, to
   insert a local QSPEC Type, e.g., RMD-QSPEC Type, and set the local
   QSPEC Type = RMD-QSPEC and set the Initiator/Local QSPEC bit to
   'Local' (and encapsulate the Initiator QSPEC in the RESERVE or
   whatever NSLP message).

   +--------------------------------+\
   |   QSPEC Type, QSPEC Procedure  | \
   +--------------------------------+ / Common QQSPEC Header
   |   Init./Local QSPEC bit=Local  |/
   +================================+\
   |  Local-QSPEC Parameter 1       | \
   +--------------------------------+  \
   |             ....               |   Local-QSPEC Parameters
   +--------------------------------+  /
   |  Local-QSPEC Parameter n       | /
   +--------------------------------+/
   | +----------------------------+ |
   | | QSPEC Type, QSPEC Procedure| |
   | +----------------------------+ |
   | | Init./Local QSPEC bit=Init.| |
   | +============================+ |
   | |                            | | Encapsulated Initiator QSPEC
   | |          ....              | |
   | +----------------------------+ |
   +--------------------------------+

   Figure 3. Defining a Local QSPEC


Ash, et al.         <draft-ietf-nsis-qspec-23.txt>           [Page 18]

Internet Draft          QoS-NSLP QSPEC Template             January 2010


   Here the QoS-NSLP only sees and passes one QSPEC up to the RMF. The
   type of the QSPEC thus may change within a local domain.  Hence

   o the QNI signals its QoS requirements with the initiator QSPEC,
   o the ingress edge QNE in the local domain translates the
     initiator QSPEC parameters to equivalent parameters in the local
     QSPEC,
   o the QNEs in the local domain only interpret the local QSPEC
     parameters
   o the egress QNE in the local domain processes the local QSPEC and
     also interprets the QSPEC parameters in the initiator QSPEC.

   The local QSPEC MUST be consistent with the initiator QSPEC.  That
   is, it MUST NOT specify a lower level of resources than specified
   by the initiator QSPEC.  For example, in RMD the TMOD parameters
   contained in the original initiator QSPEC are mapped into the
   equivalent TMOD parameter representing only the peak bandwidth in the
   local QSPEC.

   Note that it is possible to use both a) hiding a QSPEC through a
   local domain by initiating a new RESERVE at the domain edge, and
   b) defining a local QSPEC and encapsulating the initiator QSPEC, as
   defined above.  However, it is not expected that both the hiding and
   encapsulating functions would be use at the same time for the same
   flow.

   The support of local QSPECs is a new and quite powerful capability,
   which is illustrated in Figure 4 for a single flow to show where the
   initiator and local QSPECs are used.  The QNI initiates an
   end-to-end, inter-domain QoS NSLP RESERVE message containing the
   Initiator QSPEC for the Y.1541 QOSM.  As illustrated in Figure 4, the
   RESERVE message crosses multiple domains supporting different QOSMs.
   In this illustration, the initiator QSPEC arrives in an QoS NSLP
   RESERVE message at the ingress node of the local-QOSM domain.  At the
   ingress edge node of the local-QOSM domain, the end-to-end, inter-
   domain QoS-NSLP message triggers the generation of a local QSPEC, and
   the initiator QSPEC is encapsulated within the messages signaled
   through the local domain.  The local QSPEC is used for QoS processing
   in the local-QOSM domain, and the initiator QSPEC is used for QoS
   processing outside the local domain.

   In this example the QNI sets <Desired QoS>, <Minimum QoS>, <Available
   QoS> objects to include objectives for the <Path Latency>, <Path
   Jitter>, and <Path BER> parameters.  The QNE/local domain sets the
   cumulative parameters, e.g., <Path Latency>, that can be
   achieved in the <QoS Available> object (but not less than specified
   in <Minimum QoS>).  If the <Available QoS> fails to satisfy one or
   more of the <Minimum QoS> objectives, the QNE/local domain notifies
   the QNI and the reservation is aborted.  If any QNE cannot meet the
   requirements designated by the initiator QSPEC to support a QSPEC
   parameter with the M bit set to zero, the QNE sets the N flag for
   that parameter to one.  Otherwise, the QNR notifies the QNI of the

Ash, et al.         <draft-ietf-nsis-qspec-23.txt>           [Page 19]

Internet Draft          QoS-NSLP QSPEC Template             January 2010


   <QoS Available> for the reservation.

     |------|   |------|                           |------|   |------|
     | e2e  |<->| e2e  |<------------------------->| e2e  |<->| e2e  |
     | QOSM |   | QOSM |                           | QOSM |   | QOSM |
     |      |   |------|   |-------|   |-------|   |------|   |      |
     | NSLP |   | NSLP |<->| NSLP  |<->| NSLP  |<->| NSLP |   | NSLP |
     |Y.1541|   |local |   |local  |   |local  |   |local |   |Y.1541|
     | QOSM |   | QOSM |   | QOSM  |   | QOSM  |   | QOSM |   | QOSM |
     |------|   |------|   |-------|   |-------|   |------|   |------|
     -----------------------------------------------------------------
     |------|   |------|   |-------|   |-------|   |------|   |------|
     | NTLP |<->| NTLP |<->| NTLP  |<->| NTLP  |<->| NTLP |<->| NTLP |
     |------|   |------|   |-------|   |-------|   |------|   |------|
       QNI         QNE        QNE         QNE         QNE       QNR
     (End)  (Ingress Edge) (Interior)  (Interior) (Egress Edge)  (End)

       Figure 4. Example of Initiator & Local Domain QOSM Operation

4.2 Reservation Success/Failure, QSPEC Error Codes, & INFO_SPEC
    Notification

   A reservation may not be successful for several reasons:

   - a reservation may fail because the desired resources are not
     available.  This is a reservation failure condition.

   - a reservation may fail because the QSPEC is erroneous, or because
     of a QNE fault.  This is an error condition.

   A reservation may be successful even though some parameters could not
   be interpreted or updated properly:

   - a QSPEC parameter cannot be interpreted because it is an unknown
     QSPEC parameter type.  This is a QSPEC parameter not supported
     condition.  The reservation however does not fail.  The QNI can
     still decide whether to keep or tear down the reservation depending
     on the procedures specified by the QNI's QOSM.

   The following sections describe the handling of unsuccessful
   reservations and reservations where some parameters could not be met
   in more detail, as follows:

   - details on flags used inside the QSPEC to convey information on
     success or failure of individual parameters.  The formats and
     semantics of all flags are given in Section 5.
   - the content of the INFO_SPEC [QoS-NSLP], which carries a code
     indicating the outcome of reservations.
   - the generation of a RESPONSE message to the QNI containing both
     QSPEC and INFO_SPEC objects.

   Note that when there are routers along the path between the QNI and

Ash, et al.         <draft-ietf-nsis-qspec-23.txt>           [Page 20]

Internet Draft          QoS-NSLP QSPEC Template             January 2010


   QNR where QoS cannot be provided, then the QoS-NSLP generic flag
   BREAK (B) is set.  The BREAK flag is discussed in Section 3.3.5 of
   [QoS-NSLP].

4.2.1 Reservation Failure & Error E Flag

   The QSPEC parameters each have a 'reservation failure error E flag'
   to indicate which (if any) parameters could not be satisfied.  When a
   resource cannot be satisfied for a particular parameter, the QNE
   detecting the problem raises the E flag in this parameter.  Note that
   the TMOD parameter and all QSPEC parameters with the M flag set MUST
   be examined by the RMF, and all QSPEC parameters with the M flag not
   set SHOULD be examined by the RMF, and the E flag set to indicate
   whether the parameter could or could not be satisfied.  Additionally,
   the E flag in the corresponding QSPEC object MUST be raised when a
   resource cannot be satisfied for this parameter.  If the reservation
   failure problem cannot be located at the parameter level, only the E
   flag in the QSPEC object is raised.

   When an RMF cannot interpret the QSPEC because the coding is
   erroneous, it raises corresponding reservation failure E flags in the
   QSPEC.  Normally all QSPEC parameters MUST be examined by the RMF
   and the erroneous parameters appropriately flagged.  In some cases,
   however, an error condition may occur and the E flag of the
   error-causing QSPEC parameter is raised (if possible), but the
   processing of further parameters may be aborted.

   Note that if the QSPEC and/or any QSPEC parameter is found to be
   erroneous, then any QSPEC parameters not satisfied are ignored and
   the E Flags in the QSPEC object MUST NOT be set for those parameters
   (unless they are erroneous).

   Whether E flags denote reservation failure or error can be determined
   by the corresponding error code in the INFO_SPEC in QoS NSLP, as
   discussed below.

4.2.2 QSPEC Parameter Not Supported N Flag

   Each QSPEC parameter has an associated 'not supported N flag'.  If
   the not supported N flag is set, then at least one QNE along the data
   transmission path between the QNI and QNR cannot interpret the
   specified QSPEC parameter.  A QNE MUST set the not supported N flag
   if it cannot interpret the QSPEC parameter.  If the M flag for the
   parameter is not set, the message should continue to be forwarded but
   with the N flag set, and the QNI has the option of tearing the
   reservation.

   If a QNE in the path does not support a QSPEC parameter, e.g.,
   <Path Latency>, and sets the N flag, then downstream QNEs that
   support the parameter SHOULD still update the parameter, even if the
   N flag is set.  However, the presence of the N flag will indicates
   that the cumulative value only provides a bound, and the QNI/QNR

Ash, et al.         <draft-ietf-nsis-qspec-23.txt>           [Page 21]

Internet Draft          QoS-NSLP QSPEC Template             January 2010


   decides whether or not to accept the reservation with the N flag set.

4.2.3 INFO_SPEC Coding of Reservation Outcome

   As prescribed by [QoS-NSLP], the RESPONSE message always contains the
   INFO_SPEC with an appropriate 'error' code.  It usually also contains
   a QSPEC with QSPEC objects, as described in Section 4.3 on QSPEC
   Procedures.  The RESPONSE message MAY omit the QSPEC in case of a
   successful reservation.

   The following guidelines are provided in setting the error codes in
   the INFO_SPEC, based on the codes provided in Section 5.1.3.6 of
   [QoS-NSLP]:

   - INFO_SPEC error class 0x02 (Success) / 0x01 (Reservation Success):
     This code is set when all QSPEC parameters have been satisfied.  In
     this case no E Flag is set, however one or more N flags may be set

   - INFO_SPEC error class 0x04 (Transient Failure) / 0x07 (Reservation
     Failure):
     This code is set when at least one QSPEC parameter could not be
     satisfied, or when a QSPEC parameter with M flag set could not be
     interpreted.  E flags are set for the parameters that could not be
     satisfied up to the QNE issuing the RESPONSE message. The N flag is
     set for those parameters that could not be interpreted by at least
     one QNE.  In this case QNEs receiving the RESPONSE message MUST
     remove the corresponding reservation.

   - INFO_SPEC error class 0x03 (Protocol Error) / 0x0c (Malformed
     QSPEC):
     Some QSPEC parameters had associated errors, E Flags are set for
     parameters that had errors, and the QNE where the error was found
     rejects the reservation.

   - INFO_SPEC error class 0x03 (Protocol Error) / 0x0f (Incompatible
     QSPEC):
     A higher version QSPEC is signaled and not support by the QNE.

   - INFO_SPEC error class 0x06 (QoS Model Error):
     QOSM error codes can be defined by QOSM specification documents.  A
     registry is defined in Section 7 IANA Considerations.

4.2.4 QNE Generation of a RESPONSE message

   - Successful Reservation Condition

   When a RESERVE message arrives at a QNR and no E Flag is set, the
   reservation is successful.  A RESPONSE message may be generated with
   INFO_SPEC code 'Reservation Success' as described above and in the
   QSPEC Procedures described in Section 4.3.

   - Reservation Failure Condition

Ash, et al.         <draft-ietf-nsis-qspec-23.txt>           [Page 22]

Internet Draft          QoS-NSLP QSPEC Template             January 2010



   When a QNE detects that a reservation failure occurs for at least one
   parameter, the QNE sets the E Flags for the QSPEC parameters and
   QSPEC object that failed to be satisfied.  According to [QoS-NSLP],
   the QNE behavior depends on whether it is stateful or not.  When a
   stateful QNE determines the reservation failed, it formulates a
   RESPONSE message that includes an INFO_SPEC with the 'reservation
   failure' error code and QSPEC object.  The QSPEC in the RESPONSE
   message includes the failed QSPEC parameters marked with the E Flag
   to clearly identify them.

   The default action for a stateless QoS NSLP QNE that detects a
   reservation failure condition is that it MUST continue to forward the
   RESERVE  message to the next stateful QNE, with the E Flags
   appropriately set for each QSPEC parameter.  The next stateful QNE
   then formulates the RESPONSE message as described above.

   - Malformed QSPEC Error Condition

   When a stateful QNE detects that one or more QSPEC parameters are
   erroneous, the QNE sets the error code 'malformed QSPEC' in the
   INFO_SPEC.  In this case the QSPEC object with the E Flags
   appropriately set for the erroneous parameters is returned within
   the INFO_SPEC object.  The QSPEC object can be truncated or fully
   included within the INFO_SPEC.

   According to [QoS-NSLP], the QNE behavior depends on whether it is
   stateful or not.  When a stateful QNE determines a malformed QSPEC
   error condition, it formulates a RESPONSE message that includes an
   INFO_SPEC with the 'malformed QSPEC' error code and QSPEC object.
   The QSPEC in the RESPONSE message includes, if possible, only the
   erroneous QSPEC parameters and no others.  The erroneous QSPEC
   parameter(s) are marked with the E Flag to clearly identify them.  If
   QSPEC parameters are returned in the INFO-SPEC that are not marked
   with the E flag, then any values of these parameters are irrelevant
   and MUST be ignored by the QNI.

   The default action for a stateless QoS NSLP QNE that detects a
   Malformed QSPEC error condition is that it MUST continue to forward
   the RESERVE message to the next stateful QNE, with the E Flags
   appropriately set for each QSPEC parameter.  The next stateful QNE
   will then act as described in [QoS-NSLP].

   A 'malformed QSPEC' error code takes precedence over the 'reservation
   failure' error code, and therefore the case of reservation failure
   and QSPEC/RMF error conditions are disjoint and the same E Flag can
   be used in both cases without ambiguity.

4.2.5 Special Case of Local QSPEC

   When an unsuccessful reservation problem occurs inside a local domain
   where a local QSPEC is used, only the topmost (local) QSPEC is

Ash, et al.         <draft-ietf-nsis-qspec-23.txt>           [Page 23]

Internet Draft          QoS-NSLP QSPEC Template             January 2010


   affected (e.g. E flags are raised, etc.).  The encapsulated
   initiator QSPEC is untouched.  When the message (RESPONSE in case of
   stateful QNEs, RESERVE in case of stateless QNEs) however reaches the
   edge of the local domain, the local QSPEC is removed.  The edge QNE
   must update the initiator QSPEC on behalf of the entire domain,
   reflecting the information received in the local QSPEC.  This update
   concerns both parameter values and flags.  Note that some
   intelligence is needed in mapping the E flags, etc. from the local
   QSPEC to the initiator QSPEC.  For example, there may be no direct
   match between the parameters in the local and initiator QSPECs, but
   that does not mean that no E flags should be raised in the latter.

4.3 QSPEC Procedures

   While the QSPEC template aims to put minimal restrictions on usage of
   QSPEC objects, interoperability between QNEs and between QOSMs must
   be ensured.  We therefore give below an exhaustive list of QSPEC
   object combinations for the message sequences described in QoS NSLP
   [QoS-NSLP].  A specific QOSM may prescribe that only a subset of the
   procedures listed below may be used.

   Note that QoS NSLP does not mandate the usage of a RESPONSE message.
   A positive RESPONSE message will only be generated if the QNE
   includes an RII (Request Identification Information) in the RESERVE
   message, and a negative RESPONSE message is always generated in case
   of an error or failure.  Some of the QSPEC procedures below,
   however, are only meaningful when a RESPONSE message is possible.
   The QNI SHOULD in these cases include an RII.

4.3.1 Two-Way Transactions

   Here the QNI issues a RESERVE message, which may be replied to by a
   RESPONSE message.  The following 3 cases for QSPEC object usage
   exist:

   MESSAGE  | OBJECT      | OBJECTS INCLUDED   | OBJECTS INCLUDED
   SEQUENCE | COMBINATION | IN RESERVE MESSAGE | IN RESPONSE MESSAGE
   -----------------------------------------------------------------
   0        | 0           | QoS Desired        | QoS Reserved
            |             |                    |
   0        | 1           | QoS Desired        | QoS Reserved
            |             | QoS Available      | QoS Available
            |             |                    |
   0        | 2           | QoS Desired        | QoS Reserved
            |             | QoS Available      | QoS Available
            |             | Minimum QoS        |

     Table 1. Message Sequence 0: Two-Way Transactions
              Defining Object Combinations 0, 1, and 2

   Case 1:


Ash, et al.         <draft-ietf-nsis-qspec-23.txt>           [Page 24]

Internet Draft          QoS-NSLP QSPEC Template             January 2010


   If only QoS Desired is included in the RESERVE message, the implicit
   assumption is that exactly these resources must be reserved.  If this
   is not possible the reservation fails.  The parameters in QoS
   Reserved are copied from the parameters in QoS Desired.  If the
   reservation is successful, the RESPONSE message can be omitted in
   this case.  If a RESPONSE message was requested by a QNE on the
   path, the QSPEC in the RESPONSE message can be omitted.

   Case 2:

   When QoS Available is included in the RESERVE message also, some
   parameters will appear only in QoS Available and not in QoS Desired.
   It is assumed that the value of these parameters is collected for
   informational purposes only (e.g. path latency).

   However, some parameters in QoS Available can be the same as in QoS
   Desired.  For these parameters the implicit message is that the QNI
   would be satisfied by a reservation with lower parameter values than
   specified in QoS Desired.  For these parameters, the QNI seeds the
   parameter values in QoS Available to those in QoS Desired (except for
   cumulative parameters such as <path latency>).

   Each QNE interprets the parameters in QoS Available according to its
   current capabilities.  Reservations in each QNE are hence based on
   current parameter values in QoS Available (and additionally those
   parameters that only appear in QoS Desired).  The drawback of this
   approach is that, if the resulting resource reservation becomes
   gradually smaller towards the QNR, QNEs close to the QNI have an
   oversized reservation, possibly resulting in unnecessary costs for
   the user.  Of course, in the RESPONSE the QNI learns what the actual
   reservation is (from the QoS RESERVED object) and can immediately
   issue a properly sized refreshing RESERVE.  The advantage of the
   approach is that the reservation is performed in half-a-roundtrip
   time.

   The QSPEC parameter IDs and values included in the QoS Reserved
   object in the RESPONSE message MUST be the same as those in the QoS
   Desired object in the RESERVE message.  For those QSPEC parameters
   that were also included in the QoS Available object in the RESERVE
   message, their value is copied from the QoS Available object (in
   RESERVE) into the QoS Reserved object (in RESPONSE).  For the
   other QSPEC parameters, the value is copied from the QoS Desired
   object (the reservation would fail if the corresponding QoS could
   not be reserved).

   All parameters in the QoS Available object in the RESPONSE message
   are copied with their values from the QoS Available object in the
   RESERVE message (irrespective of whether they have also been copied
   into the QoS Desired object).  Note that the parameters in the QoS
   Available object can be overwritten in the RESERVE message, whereas
   they cannot be overwritten in the RESPONSE message.


Ash, et al.         <draft-ietf-nsis-qspec-23.txt>           [Page 25]

Internet Draft          QoS-NSLP QSPEC Template             January 2010


   In this case, the QNI SHOULD request a RESPONSE message since it will
   otherwise not learn what QoS is available.

   Case 3:

   This case is handled as case 2, except that the reservation fails
   when QoS Available becomes less than Minimum QoS for one parameter.
   If a parameter appears in the QoS Available object but not in the
   Minimum QoS object it is assumed that there is no minimum value for
   this parameter.

   Regarding <Traffic Handling Directives>, the default rule is that all
   QSPEC parameters that have been included in the RESERVE message by
   the QNI are also included in the RESPONSE message by the QNR with the
   value they had when arriving at the QNR.  When traveling in the
   RESPONSE message, all <Traffic Handling Directives> parameters are
   read-only.  Note that a QOSM specification may define its own
   <Traffic Handling Directives> parameters and processing rules.

4.3.2 Three-Way Transactions

   Here the QNR issues a QUERY message which is replied to by the QNI
   with a RESERVE message if the reservation was successful.  The QNR in
   turn sends a RESPONSE message to the QNI.  The following 3 cases for
   QSPEC object usage exist:

   MSG.|OBJ.|OBJECTS INCLUDED |OBJECTS INCLUDED   |OBJECTS INCLUDED
   SEQ.|COM.|IN QUERY MESSAGE |IN RESERVE MESSAGE |IN RESPONSE MESSAGE
   -------------------------------------------------------------------
   1   |0   |QoS Desired      |QoS Desired        |QoS Reserved
       |    |                 |                   |
   1   |1   |QoS Desired      |QoS Desired        |QoS Reserved
       |    |Minimum QoS      |QoS Available      |QoS Available
       |    |                 |(Minimum QoS)      |
       |    |                 |                   |
   1   |2   |QoS Desired      |QoS Desired        |QoS Reserved
       |    |QoS Available    |QoS Available      |

     Table 2. Message Sequence 1: Three-Way Transactions
              Defining Object Combinations 0, 1, and 2

   Cases 1 and 2:

   The idea is that the sender (QNR in this scenario) needs to inform
   the receiver (QNI in this scenario) about the QoS it desires.  To
   this end the sender sends a QUERY message to the receiver including a
   QoS Desired QSPEC object.  If the QoS is negotiable it additionally
   includes a (possibly zero) Minimum QoS object, as in Case 2.

   The RESERVE message includes the QoS Available object if the sender
   signaled that QoS is negotiable (i.e. it included the Minimum QoS
   object).  If the Minimum QoS object received from the sender is

Ash, et al.         <draft-ietf-nsis-qspec-23.txt>           [Page 26]

Internet Draft          QoS-NSLP QSPEC Template             January 2010


   included in the QUERY message, the QNI also includes the Minimum QoS
   object in the RESERVE message.

   For a successful reservation, the RESPONSE message in case 1 is
   optional (as is the QSPEC inside).  In case 2 however, the RESPONSE
   message is necessary in order for the QNI to learn about the QoS
   available.

   Case 3:

   This is the 'RSVP-style' scenario.  The sender (QNR in this scenario)
   issues a QUERY message with a QoS Desired object informing the
   receiver (QNI in this scenario) about the QoS it desires as above.
   It also includes a QoS Available object to collect path properties.
   Note that here path properties are collected with the QUERY message,
   whereas in the previous case 2 path properties were collected in the
   RESERVE message.

   Some parameters in the QoS Available object may the same as in the
   QoS Desired object.  For these parameters the implicit message is
   that the sender would be satisfied by a reservation with lower
   parameter values than specified in QoS Desired.

   It is possible for the QoS Available object to contain parameters
   that do not appear in the QoS Desired object.  It is assumed that the
   value of these parameters is collected for informational purposes
   only (e.g. path latency).  Parameter values in the QoS Available
   object are seeded according to the sender's capabilities.  Each QNE
   remaps or approximately interprets the parameter values according to
   its current capabilities.

   The receiver (QNI in this scenario) signals the QoS Desired object as
   follows: For those parameters that appear in both the QoS Available
   object and QoS Desired object in the QUERY message, it takes the
   (possibly remapped) QSPEC parameter values from the QoS Available
   object.  For those parameters that only appear in the QoS Desired
   object, it adopts the parameter values from the QoS Desired object.

   The parameters in the QoS Available QSPEC object in the RESERVE
   message are copied with their values from the QoS Available QSPEC
   object in the QUERY message.  Note that the parameters in the QoS
   Available object can be overwritten in the QUERY message, whereas
   they are cannot be overwritten in the RESERVE message.

   The advantage of this model compared to the sender-initiated
   reservation is that the situation of over-reservation in QNEs close
   to the QNI as described above does not occur.  On the other hand, the
   QUERY message may find, for example, a particular bandwidth is not
   available.  When the actual reservation is performed, however, the
   desired bandwidth may meanwhile have become free.  That is, the 'RSVP
   style' may result in a smaller reservation than necessary.


Ash, et al.         <draft-ietf-nsis-qspec-23.txt>           [Page 27]

Internet Draft          QoS-NSLP QSPEC Template             January 2010


   The sender includes all QSPEC parameters it cares about in the QUERY
   message.  Parameters that can be overwritten are updated by QNEs as
   the QUERY message travels towards the receiver.  The receiver
   includes all QSPEC parameters arriving in the QUERY message also in
   the RESERVE message, with the value they had when arriving at the
   receiver.  Again, QOSM-specific QSPEC parameters and procedures may
   be defined in QOSM specification documents.

   Also in this scenario, the QNI SHOULD request a RESPONSE message
   since it will otherwise not learn what QoS is available.

   Regarding <Traffic Handling Directives>, the default rule is that all
   QSPEC parameters that have been included in the RESERVE message by
   the QNI are also included in the RESPONSE message by the QNR with the
   value they had when arriving at the QNR.  When traveling in the
   RESPONSE message, all <Traffic Handling Directives> parameters are
   read-only.  Note that a QOSM specification may define its own
   <Traffic Handling Directives> parameters and processing rules.

4.3.3 Resource Queries

   Here the QNI issues a QUERY message in order to investigate what
   resources are currently available. The QNR replies with a RESPONSE
   message.

   MESSAGE  | OBJECT      | OBJECTS INCLUDED   | OBJECTS INCLUDED
   SEQUENCE | COMBINATION | IN QUERY MESSAGE   | IN RESPONSE MESSAGE
   -----------------------------------------------------------------
   2        | 0           | QoS Available      | QoS Available

         Table 3. Message Sequence 2: Resource Queries
                  Defining Object Combination 0

   Note that the QoS Available object when traveling in the QUERY
   message can be overwritten, whereas in the RESPONSE message cannot be
   overwritten.

   Regarding <Traffic Handling Directives>, the default rule is that all
   QSPEC parameters that have been included in the RESERVE message by
   the QNI are also included in the RESPONSE message by the QNR with the
   value they had when arriving at the QNR.  When traveling in the
   RESPONSE message, all <Traffic Handling Directives> parameters are
   read-only.  Note that a QOSM specification may define its own
   <Traffic Handling Directives> parameters and processing rules.

4.3.4 Bidirectional Reservations

   On a QSPEC level, bidirectional reservations are no different from
   uni-directional reservations, since QSPECs for different directions
   never travel in the same message.

4.3.5 Preemption

Ash, et al.         <draft-ietf-nsis-qspec-23.txt>           [Page 28]

Internet Draft          QoS-NSLP QSPEC Template             January 2010



   A flow can be preempted by a QNE based on QNE policy, where a
   decision to preempt a flow may account for various factors such as,
   for example, the values of the QSPEC preemption priority and
   defending priority parameters as described in Section 5.2.8.  In
   this case the reservation state for this flow is torn down in this
   QNE, and the QNE sends a NOTIFY message to the QNI, as described in
   [QoS-NSLP].  The NOTIFY message carries an INFO_SPEC with the error
   code as described in [QoS-NSLP].  A QOSM specification document may
   specify whether a NOTIFY message also carries a QSPEC object.  The
   QNI would normally tear down the preempted reservation by sending a
   RESERVE message with the TEAR flag set using the SII of the preempted
   reservation.  However, the QNI can follow other procedures as
   specified in its QOSM specification document.

4.4 QSPEC Extensibility

   Additional QSPEC parameters MAY need to be defined in the future
   and are defined in separate informational documents.  For example,
   QSPEC parameters are defined in [RMD-QOSM] and [Y.1541-QOSM].

   Guidelines on the technical criteria to be followed in evaluating
   requests for new codepoint assignments for QSPEC objects and QSPEC
   parameters are given in Section 7 (IANA Considerations).

5. QSPEC Functional Specification

   This section defines the encodings of the QSPEC parameters.  We first
   give the general QSPEC formats and then the formats of the QSPEC
   objects and parameters.

   Network octet order ('big-endian') for all 16- and 32-bit integers,
   as well as 32-bit floating point numbers, are as specified in
   [RFC4506, IEEE754, NETWORK-OCTET-ORDER].

5.1 General QSPEC Formats

   The format of the QSPEC closely follows that used in GIST [GIST] and
   QoS NSLP [QoS-NSLP].  Every object (and parameter) has the following
   general format:

   o The overall format is Type-Length-Value (in that order).

   o Some parts of the type field are set aside for control flags.

   o Length has the units of 32-bit words, and measures the length of
     Value.  If there is no Value, Length=0.  The Object length
     excludes the header.

   o Value is a whole number of 32-bit words.  If there is any padding
     required, the length and location MUST be defined by the
     object-specific format information; objects that contain variable

Ash, et al.         <draft-ietf-nsis-qspec-23.txt>           [Page 29]

Internet Draft          QoS-NSLP QSPEC Template             January 2010


    length types may need to include additional length subfields to do
     so.

   o Any part of the object used for padding or defined as reserved("r")
     MUST be set to 0 on transmission and MUST be ignored on reception.

   o Empty QSPECs and empty QSPEC Objects MUST NOT be used.

   o Duplicate objects, duplicate parameters, and/or multiple
     occurrences of a parameter MUST NOT be used.

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                      Common QSPEC Header                      |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   //                       QSPEC Objects                         //
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

5.1.1 Common Header Format

   The Common QSPEC Header is a fixed 4-octet long object containing the
   QSPEC Version, QSPEC Type, an identifier for the QSPEC Procedure (see
   Section 4.3), and an Initiator/Local QSPEC bit:

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |  Vers.|I|QSPECType|r|r|  QSPEC Proc.  |        Length         |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Vers.: Identifies the QSPEC version number.  QSPEC Version 0 is
          assigned by this specification in Section 7 (IANA
          Considerations).

   QSPEC Type: Identifies the particular type of QSPEC, e.g., a QSPEC
               Type corresponding to a particular QOSM.  QSPEC Type 0
               (default) is assigned by this specification in Section 7
               (IANA Considerations).

   QSPEC Proc.: Identifies the QSPEC procedure and is composed of two
                times 4 bits.  The first field identifies the Message
                Sequence, the second field identifies the QSPEC
                Object Combination used for this particular message
                sequence:

                 0 1 2 3 4 5 6 7
                +-+-+-+-+-+-+-+-+
                |Mes.Sq |Obj.Cmb|
                +-+-+-+-+-+-+-+-+

                The Message Sequence field can attain the following

Ash, et al.         <draft-ietf-nsis-qspec-23.txt>           [Page 30]

Internet Draft          QoS-NSLP QSPEC Template             January 2010


                values:

                0: Sender-Initiated Reservations
                1: Receiver-Initiated Reservations
                2: Resource Queries

                The Object Combination field can take the values between
                1 and 3 indicated in the tables in Section 4.3:
                Message Sequence: 0
                Object Combination: 0, 1, 2
                Semantic: see Table 1 in Section 4.3.1
                Message Sequence: 1
                Object Combination: 0, 1, 2
                Semantic: see Table 2 in Section 4.3.2
                Message Sequence: 2
                Object Combination: 0
                Semantic: see Table 3 in Section 4.3.3

   I: Initiator/Local QSPEC bit identifies whether the QSPEC is an
      initiator QSPEC or a local QSPEC, and is set to the following
      values:

                0: Initiator QSPEC
                1: Local QSPEC

   Length: The total length of the QSPEC (in 32-bit words) excluding the
           common header
   The QSPEC Objects field is a collection of
   QSPEC objects (QoS Desired, QoS Available, etc.), which share a
   common format and each contain several parameters.

5.1.2 QSPEC Object Header Format

   QSPEC objects share a common header format:

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |E|r|r|r|       Object Type     |r|r|r|r|         Length        |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   E Flag: Set if an error occurs on object level
   Object Type = 0: QoS Desired (parameters cannot be overwritten)
               = 1: QoS Available (parameters may be overwritten; see
                    Section 3.3)
               = 2: QoS Reserved (parameters cannot be overwritten)
               = 3: Minimum QoS (parameters cannot be overwritten)

   The r bits are reserved.

   Each QSPEC or QSPEC parameter within an object is similarly
   encoded in TLV format using a similar parameter header:

Ash, et al.         <draft-ietf-nsis-qspec-23.txt>           [Page 31]

Internet Draft          QoS-NSLP QSPEC Template             January 2010



    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |M|E|N|r|     Parameter ID      |r|r|r|r|         Length        |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   M Flag: When set indicates the subsequent parameter MUST be
           interpreted. Otherwise the parameter can be ignored if not
           understood.
   E Flag: When set indicates either a) a reservation failure where the
           QSPEC parameter is not met, or b) an error occurred when this
           parameter was being interpreted (see Section 4.2.1).
   N Flag: Not-supported QSPEC parameter flag (see Section 4.2.2).
   Parameter ID: Assigned consecutively to each QSPEC parameter
                 (parameter ID's are assigned to each QSPEC parameter
                 defined in this document in Section 5.2 below and in
                 Section 7/IANA Considerations).

   Parameters are usually coded individually, for example, the <Excess
   Treatment> parameter (Section 5.2.11).  However, it is also possible
   to combine several sub-parameters into one parameter field, which is
   called 'container coding'.  This coding is useful if either a) the
   sub-parameters always occur together, as for example the 5
   sub-parameters that jointly make up the TMOD, or b) in order
   to make coding more efficient when the length of each sub-parameter
   value is much less than a 32-bit word (as for example described in
   [RMD-QOSM]) and to avoid header overload.  When a container is
   defined, the Parameter ID and the M, E, and N flags refer to the
   container.  Examples of container parameters are <TMOD> (specified
   below) and the PHR container parameter specified in [RMD-QOSM].

5.2 QSPEC Parameter Coding

   The references in the following sections point to the normative
   procedures for processing the  QSPEC parameters and
   sub-parameters.

5.2.1 <TMOD-1> Parameter

   The <TMOD-1> parameter consists of the <r>, <b>, <p>, <m>, and <MPS>
   sub-parameters [RFC2212], which all must be populated in the <TMOD-1>
   parameter.  Note that a second TMOD QSPEC parameter <TMOD-2> is
   specified below in Section 5.2.2.

   The coding for the <TMOD-1> parameter is as follows:

Ash, et al.         <draft-ietf-nsis-qspec-23.txt>           [Page 32]

Internet Draft          QoS-NSLP QSPEC Template             January 2010


    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |1|E|0|r|           1           |r|r|r|r|          5            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |  TMOD Rate-1 (r) (32-bit IEEE floating point number)          |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |  TMOD Size-1 (b) (32-bit IEEE floating point number)          |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |  Peak Data Rate-1 (p) (32-bit IEEE floating point number)     |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |  Minimum Policed Unit-1 (m) (32-bit unsigned integer)         |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |  Maximum Packet Size-1 (MPS) (32-bit unsigned integer)        |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   The <TMOD-1> parameters are represented by three floating point
   numbers in single-precision IEEE floating point format [IEEE754]
   followed by two 32-bit integers in network octet order.  The first
   floating point value is the rate (r), the second floating point value
   is the bucket size (b), the third floating point is the peak rate
   (p), the first unsigned integer is the minimum policed unit (m), and
   the second unsigned integer is the maximum packet size (MPS).  The
   values of r and p are measured in octets/second, b, m, and MPS are
   measured in octets.  When r, b, and p terms are represented as IEEE
   floating point values, the sign bit MUST be zero (all values MUST be
   non-negative).  Exponents less than 127 (i.e., 0) are prohibited.
   Exponents greater than 162 (i.e., positive 35) are discouraged,
   except for specifying a peak rate of infinity.  Infinity is
   represented with an exponent of all ones (255) and a sign bit and
   mantissa of all zeroes.

5.2.2 <TMOD-2> Parameter

   A second QSPEC <TMOD-2> parameter is specified as could be needed for
   example to support some DiffServ applications.

   The coding for the <TMOD-2> parameter is as follows:

Ash, et al.         <draft-ietf-nsis-qspec-23.txt>           [Page 33]

Internet Draft          QoS-NSLP QSPEC Template             January 2010


    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |M|E|N|r|           2           |r|r|r|r|          5            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |  TMOD Rate-2 (r) (32-bit IEEE floating point number)          |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |  TMOD Size-2 (b) (32-bit IEEE floating point number)          |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |  Peak Data Rate-2 (p) (32-bit IEEE floating point number)     |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |  Minimum Policed Unit-2 (m) (32-bit unsigned integer)         |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |  Maximum Packet Size-2 (MPS) (32-bit unsigned integer)        |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   The <TMOD-2> parameters are represented by three floating point
   numbers in single-precision IEEE floating point format [IEEE754]
   followed by two 32-bit integers in network octet order.  The first
   floating point value is the rate (r), the second floating point value
   is the bucket size (b), the third floating point is the peak rate
   (p), the first unsigned integer is the minimum policed unit (m), and
   the second unsigned integer is the maximum packet size (MPS).  The
   values of r and p are measured in octets/second, b, m, and MPS are
   measured in octets.  When r, b, and p terms are represented as IEEE
   floating point values, the sign bit MUST be zero (all values MUST be
   non-negative).  Exponents less than 127 (i.e., 0) are prohibited.
   Exponents greater than 162 (i.e., positive 35) are discouraged,
   except for specifying a peak rate of infinity.  Infinity is
   represented with an exponent of all ones (255) and a sign bit and
   mantissa of all zeroes.

5.2.3 <Path Latency> Parameter

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |M|E|N|r|           3           |r|r|r|r|          1            |
   +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
   |                Path Latency (32-bit unsigned integer)         |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   The Path Latency [RFC2215] is a single 32-bit unsigned integer in
   network octet order.  The intention of the Path Latency parameter is
   the same as the Minimal Path Latency parameter defined in Section 3.4
   of [RFC2215].  The purpose of this parameter is to provide a baseline
   minimum path latency for use with services which provide estimates or
   bounds on additional path delay, such as in [RFC2212].  Together with
   the queuing delay bound offered by [RFC2212] and similar services,
   this parameter gives the application knowledge of both the minimum
   and maximum packet delivery delay.


Ash, et al.         <draft-ietf-nsis-qspec-23.txt>           [Page 34]

Internet Draft          QoS-NSLP QSPEC Template             January 2010


   The composition rule for the <Path Latency> parameter is summation
   with a clamp of (2**32) - 1 on the maximum value.  The latencies are
   average values reported in units of one microsecond.  A system with
   resolution less than one microsecond MUST set unused digits to zero.
   An individual QNE can add a latency value between 1 and 2**28
   (somewhat over two minutes) and the total latency added across all
   QNEs can range as high as (2**32)-2.  If the sum of the different
   elements delays exceeds (2**32)-2, the end-to-end cumulative delay
   SHOULD be reported as indeterminate = (2**32)-1.  A QNE that cannot
   accurately predict the latency of packets it is processing MUST raise
   the not-supported flag and either leave the value of Path Latency as
   is, or add its best estimate of its lower bound.  A raised
   not-supported flag indicates the value of Path Latency is a lower
   bound of the real Path Latency.  The distinguished value (2**32)-1 is
   taken to mean indeterminate latency because the composition function
   limits the composed sum to this value, it indicates the range of the
   composition calculation was exceeded.

5.2.4 <Path Jitter> Parameter

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |M|E|N|r|           4           |r|r|r|r|          4            |
   +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
   |    Path Jitter STAT1(variance) (32-bit unsigned integer)      |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |    Path Jitter STAT2(99.9%-ile) (32-bit unsigned integer)     |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | Path Jitter STAT3(minimum Latency) (32-bit unsigned integer)  |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |    Path Jitter STAT4(Reserved)     (32-bit unsigned integer)  |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   The Path Jitter is a set of four 32-bit unsigned integers in network
   octet order [RFC3393, Y.1540, Y.1541]. As noted in Section 3.3.2, the
   Path Jitter parameter is called "IP Delay Variation" in [RFC3393].
   The Path Jitter parameter is the combination of four statistics
   describing the Jitter distribution with a clamp of (2**32) - 1 on the
   maximum of each value.  The jitter STATs are reported in units of one
   microsecond.  A system with resolution less than one microsecond MUST
   set unused digits to zero.  An individual QNE can add jitter values
   between 1 and 2**28 (somewhat over two minutes) and the total jitter
   computed across all QNEs can range as high as (2**32)-2. If the
   combination of the different element values exceeds (2**32)-2, the
   end-to-end cumulative jitter SHOULD be reported as indeterminate.  A
   QNE that cannot accurately predict the jitter of packets it is
   processing MUST raise the not-supported flag and either leave the
   value of Path Jitter as is, or add its best estimate of its STAT
   values.  A raised not-supported flag indicates the value of Path
   Jitter is a lower bound of the real Path Jitter.  The distinguished
   value (2**32)-1 is taken to mean indeterminate jitter.  A QNE that

Ash, et al.         <draft-ietf-nsis-qspec-23.txt>           [Page 35]

Internet Draft          QoS-NSLP QSPEC Template             January 2010


   cannot accurately predict the jitter of packets it is processing
   SHOULD set its local path jitter parameter to this value.  Because
   the composition function limits the total to this value, receipt of
   this value at a network element or application indicates that the
   true path jitter is not known.  This MAY happen because one or more
   network elements could not supply a value, or because the range of
   the composition calculation was exceeded.

   NOTE: The Jitter composition function makes use of the <Path Latency>
   parameter.  Composition functions for loss, latency and jitter may be
   found in [Y.1541]. Development continues on methods to combine jitter
   values to estimate the value of the complete path, and additional
   statistics may be needed to support new methods (the methods are
   standardized in [RFC5481, COMPOSITION]).

5.2.5 <Path PLR> Parameter

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |M|E|N|r|           5           |r|r|r|r|          1            |
   +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
   |             Path Packet Loss Ratio (32-bit floating point)    |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   The Path PLR is a single 32-bit single precision IEEE floating point
   number in network octet order [Y.1541].  As defined in [Y.1540], Path
   PLR is the ratio of total lost IP packets to total transmitted IP
   packets.  An evaluation interval of 1 minute is suggested in
   [Y.1541], in which the number of losses observed is directly related
   to the confidence in the result.  The composition rule for the <Path
   PLR> parameter is summation with a clamp of 10^-1 on the maximum
   value.  The PLRs are reported in units of 10^-11.  A system with
   resolution less than 10^-11 MUST set unused digits to zero.  An
   individual QNE adds its local PLR value (up to a maximum of 10^-2) to
   the total Path PLR value (up to a maximum of 10^-1) , where the
   acceptability of the total Path PLR value added across all QNEs is
   determined based on the QOSM being used.  The maximum limit of 10^-2
   on a QNE's local PLR value and the maximum limit (clamp value) of
   10^-1 on accumulated end-to-end Path PLR value are used to preserve
   the accuracy of the simple additive accumulation function specified
   and to avoid more complex accumulation functions.  Furthermore, if
   these maximums are exceeded, then the path would likely not meet the
   QoS objectives.  If the sum of the different elements values exceeds
   10^-1, the end-to-end cumulative PLR SHOULD be reported as
   indeterminate.  A QNE that cannot accurately predict the PLR of
   packets it is processing MUST raise the not-supported flag and either
   leave the value of Path PLR as is, or add its best estimate of its
   lower bound.  A raised not-supported flag indicates the value of Path
   PLR is a lower bound of the real Path PLR.  The distinguished value
   10^-1 is taken to mean indeterminate PLR.  A QNE which cannot
   accurately predict the PLR of packets it is processing SHOULD set its

Ash, et al.         <draft-ietf-nsis-qspec-23.txt>           [Page 36]

Internet Draft          QoS-NSLP QSPEC Template             January 2010


   local path PLR parameter to this value.  Because the composition
   function limits the composed sum to this value, receipt of this value
   at a network element or application indicates that the true path PLR
   is not known.  This MAY happen because one or more network elements
   could not supply a value, or because the range of the composition
   calculation was exceeded.

5.2.6 <Path PER> Parameter

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |M|E|N|r|           6           |r|r|r|r|          1            |
   +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
   |             Path Packet Error Ratio (32-bit floating point)   |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   The Path PER is a single 32-bit single precision IEEE floating point
   number in network octet order [Y.1541.  As defined in [Y.1540], Path
   PER is the ratio of total errored IP packets to the total of
   successful IP Packets plus errored IP packets, in which the number of
   errored packets observed is directly related to the confidence in
   the result.  The composition rule for the <Path PER> parameter is
   summation with a clamp of 10^-1 on the maximum value.  The PERs are
   reported in units of 10^-11.  A system with resolution less than
   10^-11 MUST set unused digits to zero.  An individual QNE adds its
   local PER value (up to a maximum of 10^-2) to the total Path PER
   value (up to a maximum of 10^-1) , where the acceptability of the
   total Path PER value added across all QNEs is determined based on the
   QOSM being used.  The maximum limit of 10^-2 on a QNE's local PER
   value and the maximum limit (clamp value) of 10^-1 on accumulated
   end-to-end Path PER value are used to preserve the accuracy of the
   simple additive accumulation function specified and to avoid more
   complex accumulation functions.   Furthermore, if these maximums are
   exceeded, then the path would likely not meet the QoS objectives.
   If the sum of the different elements values exceeds 10^-1, the
   end-to-end cumulative PER SHOULD be reported as indeterminate.  A QNE
   that cannot accurately predict the PER of packets it is processing
   MUST raise the not-supported flag and either leave the value of Path
   PER as is, or add its best estimate of its lower bound.  A raised
   not-supported flag indicates the value of Path PER is a lower bound
   of the real Path PER.  The distinguished value 10^-1 is taken to mean
   indeterminate PER.  A QNE which cannot accurately predict the PER of
   packets it is processing SHOULD set its local path PER parameter to
   this value.  Because the composition function limits the composed sum
   to this value, receipt of this value at a network element or
   application indicates that the true path PER is not known.  This MAY
   happen because one or more network elements could not supply a value,
   or because the range of the composition calculation was exceeded.

5.2.7 <Slack Term> Parameter


Ash, et al.         <draft-ietf-nsis-qspec-23.txt>           [Page 37]

Internet Draft          QoS-NSLP QSPEC Template             January 2010


    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |M|E|N|r|           7           |r|r|r|r|          1            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |        Slack Term (S)  (32-bit unsigned integer)              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Slack term S MUST be nonnegative and is measured in microseconds
   [RFC2212].  The Slack term, S, is represented as a 32-bit unsigned
   integer.  Its value can range from 0 to (2**32)-1 microseconds.

5.2.8 <Preemption Priority> & <Defending Priority> Parameters

   The coding for the <Preemption Priority> & <Defending Priority>
   sub-parameters is as follows RFC3181]:

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |M|E|N|r|           8           |r|r|r|r|          1            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |    Preemption Priority        |      Defending Priority       |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Preemption Priority: The priority of the new flow compared with the
   defending priority of previously admitted flows.  Higher values
   represent higher priority.

   Defending Priority: Once a flow is admitted, the preemption priority
   becomes irrelevant.  Instead, its defending priority is used to
   compare with the preemption priority of new flows.

   As specified in [RFC3181], <Preemption Priority> and <Defending
   Priority> are 16-bit integer values and both MUST be populated if the
   parameter is used.

5.2.9 <Admission Priority> Parameter

   The coding for the <Admission Priority> parameter is as follows:

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |M|E|N|r|           9           |r|r|r|r|          1            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |Y.2171 Adm Pri.|Admis. Priority|        (Reserved)             |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Two fields are provided for the <Admission Priority> parameter and
   are populated according to the following rules.


Ash, et al.         <draft-ietf-nsis-qspec-23.txt>           [Page 38]

Internet Draft          QoS-NSLP QSPEC Template             January 2010


   <Y.2171 Admission Priority> values are globally significant on an
   end-to-end basis.  High priority flows, normal priority flows, and
   best-effort priority flows can have access to resources depending on
   their admission priority value, as described in [Y.2171], as follows:

   <Y.2171 Admission Priority>:

   0 - best-effort priority flow
   1 - normal priority flow
   2 - high priority flow

   If the QNI signals <Y.2171 Admission Priority>, it populates both
   the <Y.2171 Admission Priority> and <Admission Priority> fields with
   the same value.  Downstream QNEs MUST NOT change the value in the
   <Y.2171 Admission Priority> field so that end-to-end consistency is
   maintained and MUST treat the flow priority according to the value
   populated.  A QNE in a local domain MAY reset a different value of
   <Admission Priority> in a local QSPEC, but as specified in Section
   4.1 the local QSPEC MUST be consistent with the initiator QSPEC.
   That is, the local domain MUST specify an <Admission Priority> in the
   local QSPEC functionally equivalent to the <Y.2171 Admission
   Priority> specified by the QNI in the initiator QSPEC.

   If the QNI signals admission priority according to [EMERGENCY-RSVP],
   it populates a locally significant value in the <Admission Priority>
   field and places all 1's in the <Y.2171 Admission Priority> field.
   In this case the functional significance of the <Admission Priority>
   value is specified by the local network administrator.  Higher
   values indicate higher priority.  Downstream QNEs and RSVP nodes MAY
   reset the <Admission Priority> value according to the local rules
   specified by the local network administrator, but MUST NOT reset the
   value of the <Y.2171 Admission Priority> field.

   A reservation without an <Y.2171 Admission Priority> parameter MUST
   be treated as a reservation with an <Y.2171 Admission Priority> = 1.

5.2.10 <RPH Priority> Parameter

   The coding for the <RPH Priority> parameter is as follows:

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |M|E|N|r|           10          |r|r|r|r|          1            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |         RPH Namespace         | RPH Priority  |   (Reserved)  |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   [RFC4412] defines a resource priority header (RPH) with parameters
   "RPH Namespace" and "RPH Priority", and if populated is applicable
   only to flows with high admission priority.  A registry is created
   in [RFC4412] and extended in [EMERGENCY-RSVP] for IANA to assign

Ash, et al.         <draft-ietf-nsis-qspec-23.txt>           [Page 39]

Internet Draft          QoS-NSLP QSPEC Template             January 2010


   the RPH priority parameter.  In the extended registry, "Namespace
   Numerical Values" are assigned by IANA to RPH Namespaces and
   "Priority Numerical Values" are assigned to the RPH Priority.

   Note that the <Admission Priority> parameter MAY be used in
   combination with the <RPH Priority> parameter, which depends on the
   supported QOSM.  Furthermore, if more than one RPH namespace is
   supported by a QOSM, then the QOSM MUST specify how the mapping
   between the priorities belonging to the different RPH namespaces are
   mapped to each other.

   Note also that additional work is needed to communicate these flow
   priority values to bearer-level network elements
   [VERTICAL-INTERFACE].

   For the 4 priority parameters, the following cases are permissible
   (procedures specified in references):

   1 parameter: <Admission Priority> [Y.2171]
   2 parameters: <Admission Priority>, <RPH Priority> [RFC4412]
   2 parameters: <Preemption Priority>, <Defending Priority> [RFC3181]
   3 parameters: <Preemption Priority>, <Defending Priority>,
                 <Admission Priority> [3GPP-1, 3GPP-2, 3GPP-3]
   4 parameters:  <Preemption Priority>, <Defending Priority>,
                 <Admission Priority>, <RPH Priority> [3GPP-1, 3GPP-2,
                 3GPP-3]

   It is permissible to have <Admission Priority> without <RPH
   Priority>, but not permissible to have <RPH Priority> without
   <Admission Priority> (alternatively <RPH Priority> is ignored in
   instances without <Admission Priority>).

   eMLPP-like functionality (as defined in [3GPP-1, 3GPP-2]) specifies
   use of <Admission Priority> corresponding to the 'queuing allowed'
   part of eMLPP as well as <Preemption/Defending Priority>
   corresponding to the 'preemption capable' and 'may be preempted'
   parts of eMLPP.

5.2.11 <Excess Treatment> Parameter

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |M|E|N|r|           11          |r|r|r|r|          1            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | Excess Trtmnt |Remark Value |           Reserved              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Excess Treatment: Indicates how the QNE SHOULD process out-of-profile
   traffic, that is, traffic not covered by the <Traffic> parameter.
   The excess treatment parameter is set by the QNI.  Allowed values are
   as follows:

Ash, et al.         <draft-ietf-nsis-qspec-23.txt>           [Page 40]

Internet Draft          QoS-NSLP QSPEC Template             January 2010



   0: drop
   1: shape
   2: remark
   3: no metering or policing is permitted

   The default excess treatment in case that no Excess Treatment
   Parameter is specified is that there are no guarantees to excess
   traffic, i.e. a QNE can do whatever it finds suitable.

   When excess treatment is set to 'drop', all marked traffic MUST be
   dropped by the QNE/RMF.

   When excess treatment is set to 'shape', it is expected that the QoS
   Desired object carries a TMOD parameter and excess traffic is shaped
   to this TMOD.  The bucket size in the TMOD parameter for excess
   traffic specifies the queuing behavior, and when the shaping causes
   unbounded queue growth at the shaper, any traffic in excess of the
   TMOD for excess traffic SHOULD be dropped.  If excess treatment is
   set to 'shape' and no TMOD parameter is given, the E flag is set for
   the parameter and the reservation fails.  If excess treatment is set
   to 'shape' and two TMOD parameters are specified, then the QOSM
   specification dictates how excess traffic should be shaped in that
   case.

   When excess treatment is set to 'remark', the excess treatment
   parameter MUST carry the remark value, and the remark values and
   procedures MUST be specified in the QOSM specification document.  For
   example, packets may be remarked to pertain to a particular QoS class
   (DSCP value).  In the latter case, remarking relates to a DiffServ
   model where packets arrive marked as belonging to a  certain QoS
   class/DSCP, and when they are identified as excess, they should then
   be remarked to a different QoS Class (DSCP value) indicated in the
   'Remark Value', as follows:

   Remark Value (6 bits): indicates DSCP value [RFC2474] to remark
                          packets to when identified as excess

   If 'no metering or policing is permitted' is signaled, the QNE should
   accept the excess treatment parameter set by the sender with special
   care so that excess traffic should not cause a problem.  To request
   the Null Meter [RFC3290] is especially strong, and should be used
   with caution.

   A NULL metering application [RFC2997] would not include the traffic
   profile, and conceptually it should be possible to support this with
   the QSPEC.  A QSPEC without a traffic profile is not excluded by the
   current specification.  However, note that the traffic profile is
   important even in those cases when the excess treatment is not
   specified, e.g., in negotiating bandwidth for the best effort
   aggregate.  However, a "NULL Service QOSM" would need to be specified
   where the desired QNE Behavior and the corresponding QSPEC format are

Ash, et al.         <draft-ietf-nsis-qspec-23.txt>           [Page 41]

Internet Draft          QoS-NSLP QSPEC Template             January 2010


   described.

   As an example behavior for a NULL metering, in the properly
   configured DiffServ router, the resources are shared between the
   aggregates by the scheduling disciplines.  Thus, if the incoming rate
   increases, it will influence the state of a queue within that
   aggregate, while all the other aggregates will be provided sufficient
   bandwidth resources.  NULL metering is useful for best effort and
   signaling data, where there is no need to meter and police this data
   as it will be policed implicitly by the allocated bandwidth and,
   possibly, active queue management mechanism.

5.2.12 <PHB Class> Parameter

   The coding for the <PHB Class> parameter is as follows [RFC3140]:

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |M|E|N|r|           12          |r|r|r|r|          1            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |           PHB Field           |            (Reserved)         |
   +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+

   The above encoding is consistent with [RFC3140], and the following
   Four figures show four possible formats based on the value of the PHB
   Field.

Single PHB:

    0                   1
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | DSCP      |0 0 0 0 0 0 0 0 0 0|
   +---+---+---+---+---+---+---+---+

Set of PHBs:

    0                   1
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | DSCP      |0 0 0 0 0 0 0 0 1 0|
   +---+---+---+---+---+---+---+---+

   PHBs not defined by standards action, i.e., experimental or local use
   PHBs as allowed by [RFC2474].  In this case an arbitrary 12 bit PHB
   identification code, assigned by the IANA, is placed left-justified
   in the 16 bit field.  Bit 15 is set to 1, and bit 14 is zero for a
   single PHB or 1 for a set of PHBs.  Bits 12 and 13 are zero.

Single non-standard PHB (experimental or local):


Ash, et al.         <draft-ietf-nsis-qspec-23.txt>           [Page 42]

Internet Draft          QoS-NSLP QSPEC Template             January 2010


    0                   1
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |      PHB ID CODE      |0 0 0 1|
   +---+---+---+---+---+---+---+---+

Set of non-standard PHBs (experimental or local):

    0                   1
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |      PHB ID CODE      |0 0 1 1|
   +---+---+---+---+---+---+---+---+

   Bits 12 and 13 are reserved either for expansion of the PHB
   identification code, or for other use, at some point in the future.

   In both cases, when a single PHBID is used to identify a set of PHBs
   (i.e., bit 14 is set to 1), that set of PHBs MUST constitute a PHB
   Scheduling Class (i.e., use of PHBs from the set MUST NOT cause
   intra-microflow traffic reordering when different PHBs from the set
   are applied to traffic in the same microflow).  The set of AF1x PHBs
   [RFC2597] is an example of a PHB Scheduling Class.  Sets of PHBs
   that do not constitute a PHB Scheduling Class can be identified by
   using more than one PHBID.

   The registries needed to use RFC 3140 already exist, see
   [DSCP-REGISTRY, PHBID-CODES-REGISTRY].  Hence, no new registry needs
   to be created for this purpose.

5.2.13 <DSTE Class Type> Parameter

   A description of the semantic of the parameter values can be found in
   [RFC4124].  The coding for the <DSTE Class Type> parameter is as
   follows:

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |M|E|N|r|           13          |r|r|r|r|          1            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |DSTE Cls. Type |                (Reserved)                     |
   +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+

   DSTE Class Type: Indicates the DSTE class type.  Values currently
   allowed are 0, 1, 2, 3, 4, 5, 6, 7.

5.2.14 <Y.1541 QoS Class> Parameter

   The coding for the <Y.1541 QoS Class> parameter [Y.1541] is as
   follows:


Ash, et al.         <draft-ietf-nsis-qspec-23.txt>           [Page 43]

Internet Draft          QoS-NSLP QSPEC Template             January 2010


    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |M|E|N|r|           14          |r|r|r|r|          1            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |Y.1541 QoS Cls.|                (Reserved)                     |
   +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+

   Y.1541 QoS Class: Indicates the Y.1541 QoS Class. Values currently
   allowed are 0, 1, 2, 3, 4, 5, 6, 7.

   Class 0:
   Mean delay <= 100 ms, delay variation <= 50 ms, loss ratio <= 10^-3.
   Real-time, highly interactive applications, sensitive to jitter.
   Application examples include VoIP, Video Teleconference.

   Class 1:
   Mean delay <= 400 ms, delay variation <= 50 ms, loss ratio <= 10^-3.
   Real-time, interactive applications, sensitive to jitter.
   Application examples include VoIP, Video Teleconference.

   Class 2:
   Mean delay <= 100 ms, delay variation unspecified, loss ratio <=
   10^-3.  Highly interactive transaction data.  Application examples
   include signaling.

   Class 3:
   Mean delay <= 400 ms, delay variation unspecified, loss ratio <=

   10^-3.  Interactive transaction data.  Application examples include
   signaling.

   Class 4:
   Mean delay <= 1 sec, delay variation unspecified, loss ratio <=
   10^-3.  Low Loss Only applications.  Application examples include
   short transactions, bulk data, video streaming.

   Class 5:
   Mean delay unspecified, delay variation unspecified, loss ratio
   unspecified.  Unspecified applications.  Application examples include
   traditional applications of default IP networks.

   Class 6:
   Mean delay <= 100 ms, delay variation <= 50 ms, loss ratio <= 10^-5.
   Applications that are highly sensitive to loss, such as television
   transport, high-capacity TCP transfers, and TDM circuit emulation.

   Class 7:
   Mean delay <= 400 ms, delay variation <= 50 ms, loss ratio <= 10^-5.
   Applications that are highly sensitive to loss, such as television
   transport, high-capacity TCP transfers, and TDM circuit emulation.


Ash, et al.         <draft-ietf-nsis-qspec-23.txt>           [Page 44]

Internet Draft          QoS-NSLP QSPEC Template             January 2010


6. Security Considerations

   QSPEC security is directly tied to QoS NSLP security, and the QoS
   NSLP document [QoS-NSLP] has a very detailed security discussion in
   Section 7.  All the considerations detailed in Section 7 of
   [QoS-NSLP] apply to QSPEC.

   The priority parameter raises possibilities for theft of service
   attacks because users could claim an emergency priority for their
   flows without real need, thereby effectively preventing serious
   emergency calls to get through. Several options exist for countering
   such attacks, for example

   - only some user groups (e.g. the police) are authorized to set the
   emergency priority bit

   - any user is authorized to employ the emergency priority bit for
   particular destination addresses (e.g. police)

7. IANA Considerations

   This section defines the registries and initial codepoint assignments
   for the QSPEC template, in accordance with BCP 26 RFC 5226 [RFC5226].
   It also defines the procedural requirements to be followed by IANA in
   allocating new codepoints.

   This specification creates the following registries with the
   structures as defined below:

   Object Types (12 bits):
   The following values are allocated as specified in Section 5:
   0: QoS Desired
   1: QoS Available
   2: QoS Reserved
   3: Minimum QoS
   The allocation policies for further values are as follows:
   4-63: Specification Required
   64-127: Private/Experimental Use
   128-4095: Reserved
   (Note: 'Reserved' just means 'do not give these out'.)

   QSPEC Version (4 bits):
   The following value is allocated by this specification:
   0: assigned to Version 0 QSPEC
   The allocation policies for further values are as follows:
   1-15: Specification Required
   A specification is required to depreciate, delete, or modify QSPEC
   versions.

   QSPEC Type (5 bits):
   The following values are allocated by this specification:
   0: Default

Ash, et al.         <draft-ietf-nsis-qspec-23.txt>           [Page 45]

Internet Draft          QoS-NSLP QSPEC Template             January 2010


   1: Y.1541-QOSM [Y.1541-QOSM]
   2: RMD-QOSM [RMD-QOSM]
   The allocation policies for further values are as follows:
   3-12: Specification Required
   13-16: Local/Experimental Use
   17-31: Reserved

   QSPEC Procedure (8 bits):
   The QSPEC Procedure object consists of the Message Sequence
   parameter (4 bits) and the Object Combination parameter (4 bits), as
   discussed in Section 4.3.  Message Sequences 0 (Two-Way
   Transactions), 1 (Three-Way Transactions), and 2 (Resource Queries)
   are explained in Sections 4.3.1, 4.3.2, and 4.3.3, respectively.
   Tables 1, 2, and 3 in Section 4.3 assign the Object Combination # to
   Message Sequences 0, 1, and, 2, respectively.  The values assigned by
   this specification for the Message Sequence parameter and the Object
   Combination parameter are summarized here:

   MSG.|OBJ.|OBJECTS INCLUDED |OBJECTS INCLUDED   |OBJECTS INCLUDED
   SEQ.|COM.|IN QUERY MESSAGE |IN RESERVE MESSAGE |IN RESPONSE MESSAGE
   -------------------------------------------------------------------
   0   |0   |N/A              |QoS Desired        |QoS Reserved
       |    |                 |                   |
   0   |1   |N/A              |QoS Desired        |QoS Reserved
       |    |N/A              |QoS Available      |QoS Available
       |    |                 |                   |
   0   |2   |N/A              |QoS Desired        |QoS Reserved
       |    |N/A              |QoS Available      |QoS Available
       |    |N/A              |Minimum QoS        |
       |    |                 |                   |
   1   |0   |QoS Desired      |QoS Desired        |QoS Reserved
       |    |                 |                   |
   1   |1   |QoS Desired      |QoS Desired        |QoS Reserved
       |    |Minimum QoS      |QoS Available      |QoS Available
       |    |                 |(Minimum QoS)      |
       |    |                 |                   |
   1   |2   |QoS Desired      |QoS Desired        |QoS Reserved
       |    |QoS Available    |QoS Available      |
       |    |                 |                   |
   2   |0   |QoS Available    |N/A                |QoS Available

   The allocation policies for further values of the Message Sequence
   parameter (4 bits) are as follows:
   3-15: Specification Required
   The allocation policies for further values of the Object Combination
   parameter (4 bits) are as follows:
   3-15: Specification Required (Message Sequence 0)
   2-15: Specification Required (Message Sequence 1)
   1-15: Specification Required (Message Sequence 2)
   0-15: Specification Required (Message Sequence 3-15)

   A specification is required to depreciate, delete, or modify QSPEC

Ash, et al.         <draft-ietf-nsis-qspec-23.txt>           [Page 46]

Internet Draft          QoS-NSLP QSPEC Template             January 2010


   Procedures.

   Error Code (16 bits)
   The allocation policies are as follows:
   0-127: Specification Required
   128-255: Private/Experimental Use
   255-65535: Reserved
   A specification is required to depreciate, delete, or modify Error
   Codes.

   Parameter ID (12 bits):
   The following values are allocated by this specification:
   1-14: assigned as specified in Section 5.2:
   Parameter ID 1: <TMOD-1>
                2: <TMOD-2>
                3: <Path Latency>
                4: <Path Jitter>
                5: <Path PLR>
                6: <Path PER>
                7: <Slack Term>
                8: <Preemption Priority> & <Defending Priority>
                9: <Admission Priority>
                10: <RPH Priority>
                11: <Excess Treatment>
                12: <PHB Class>
                13: <DSTE Class Type>
                14: <Y.1541 QoS Class>

   The allocation policies for further values are as follows:
   15-255: Specification Required
   256-1024: Private/Experimental Use
   1025-4095: Reserved

   A specification is required to depreciate, delete, or modify
   Parameter IDs.

   Y.2171 Admission Priority Parameter (8 bits):
   The following values are allocated by this specification:
   0-2: assigned as specified in Section 5.2.9:
   Y.2171 Admission Priority 0: best-effort priority flow
                             1: normal priority flow
                             2: high priority flow
   The allocation policies for further values are as follows:
   3-63: Specification Required
   64-255: Reserved
   RPH Namespace Parameter (16 bits):
   Note that [RFC4412] creates a registry for RPH Namespace and Priority
   values already (see Section 12.6 of [RFC4412]), and an extension to
   this registry is created in [EMERGENCY-RSVP], which will also be used
   for the QSPEC RPH parameter.  In the extended registry, "Namespace
   Numerical Values" are assigned by IANA to RPH Namespaces and
   "Priority Numerical Values" are assigned to the RPH Priority.  There

Ash, et al.         <draft-ietf-nsis-qspec-23.txt>           [Page 47]

Internet Draft          QoS-NSLP QSPEC Template             January 2010


   are no additional IANA requirements made by this specification for
   the RPH Namespace Parameter.

   Excess Treatment Parameter (8 bits):
   The following values are allocated by this specification:
   0-3: assigned as specified in Section 5.2.11:
   Excess Treatment Parameter 0: drop
                              1: shape
                              2: remark
                              3: no metering or policing is
                                 permitted
   The allocation policies for further values are as follows:
   4-63: Specification Required
   64-255: Reserved

   Y.1541 QoS Class Parameter (8 bits):
   The following values are allocated by this specification:
   0-7: assigned as specified in Section 5.2.14:
   Y.1541 QoS Class Parameter 0: Y.1541 QoS Class 0
                              1: Y.1541 QoS Class 1
                              2: Y.1541 QoS Class 2
                              3: Y.1541 QoS Class 3
                              4: Y.1541 QoS Class 4
                              5: Y.1541 QoS Class 5
                              6: Y.1541 QoS Class 6
                              7: Y.1541 QoS Class 7
   The allocation policies for further values are as follows:
   8-63: Specification Required
   64-255: Reserved

8. Acknowledgements

   The authors would like to thank (in alphabetical order) David Black,
   Ken Carlberg, Anna Charny, Christian Dickman, Adrian Farrel, Ruediger
   Geib, Matthias Friedrich, Xiaoming Fu, Janet Gunn, Robert Hancock,
   Chris Lang, Jukka Manner, Martin Stiemerling, An Nguyen, Tom Phelan,
   James Polk, Alexander Sayenko, John Rosenberg, Hannes Tschofenig, and
   Sven van den Bosch for their very helpful suggestions.

9. Contributors

   This document is the result of the NSIS Working Group effort.  In
   addition to the authors/editors listed in Section 12, the following
   people contributed to the document:

   Roland Bless
   Institute of Telematics, Universitaet Karlsruhe (TH)
   Zirkel 2
   Karlsruhe  76131
   Germany
   Phone: +49 721 608 6413
   Email: bless@tm.uka.de

Ash, et al.         <draft-ietf-nsis-qspec-23.txt>           [Page 48]

Internet Draft          QoS-NSLP QSPEC Template             January 2010


   URI:   http://www.tm.uka.de/~bless

   Chuck Dvorak
   AT&T
   Room 2A37
   180 Park Avenue, Building 2
   Florham Park, NJ 07932
   Phone: + 1 973-236-6700
   Fax:+1 973-236-7453
   Email: cdvorak@research.att.com

   Yacine El Mghazli
   Alcatel
   Route de Nozay
   91460 Marcoussis cedex
   FRANCE
   Phone: +33 1 69 63 41 87
   Email: yacine.el_mghazli@alcatel.fr

   Georgios Karagiannis
   University of Twente
   P.O. BOX 217
   7500 AE Enschede
   The Netherlands
   Email: g.karagiannis@ewi.utwente.nl

   Andrew McDonald
   Siemens/Roke Manor Research
   Roke Manor Research Ltd.
   Romsey, Hants SO51 0ZN
   UK
   Email: andrew.mcdonald@roke.co.uk

   Al Morton
   AT&T
   Room D3-3C06
   200 S. Laurel Avenue
   Middletown, NJ 07748
   Phone: + 1 732 420-1571
   Fax: +.1 732 368-1192
   Email: acmorton@att.com

   Bernd Schloer
   University of Goettingen
   Email: bschloer@cs.uni-goettingen.de

   Percy Tarapore
   AT&T
   Room D1-33
   200 S. Laurel Avenue
   Middletown, NJ 07748
   Phone: + 1 732 420-4172

Ash, et al.         <draft-ietf-nsis-qspec-23.txt>           [Page 49]

Internet Draft          QoS-NSLP QSPEC Template             January 2010


   Email: tarapore@.att.com

   Lars Westberg
   Ericsson Research
   Torshamnsgatan 23
   SE-164 80 Stockholm, Sweden
   Email: Lars.Westberg@ericsson.com

10. Normative References

   [3GPP-1]  3GPP TS 22.067 V7.0.0 (2006-03) Technical Specification,
             3rd Generation Partnership Project; Technical Specification
             Group Services and System Aspects; enhanced Multi Level
             Precedence and Preemption service (eMLPP) - Stage 1
             (Release 7).

   [3GPP-2]  3GPP TS 23.067 V7.1.0 (2006-03) Technical Specification,
             3rd Generation Partnership Project; Technical Specification
             Group Core Network; enhanced Multi-Level Precedence and
             Preemption service (eMLPP) - Stage 2 (Release 7).

   [3GPP-3]  3GPP TS 24.067 V6.0.0 (2004-12) Technical Specification,
             3rd Generation Partnership Project; Technical Specification
             Group Core Network; enhanced Multi-Level Precedence and
             Preemption service (eMLPP) - Stage 3 (Release 6).

   [GIST]    Schulzrinne, H., Hancock, R., "GIST: General Internet
             Signaling Transport," work in progress.

   [QoS-NSLP] Manner, J., et al., "NSLP for Quality-of-Service
             Signaling," work in progress.

   [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
             Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC2210] Wroclawski, J., "The Use of RSVP with IETF Integrated
             Services", RFC 2210, September 1997.

   [RFC2212] Shenker, S., et al., "Specification of Guaranteed Quality
             of Service," September 1997.

   [RFC2215] Shenker, S., Wroclawski, J., "General Characterization
             Parameters for Integrated Service Network Elements", RFC
             2215, Sept. 1997.

   [RFC3140] Black, D., et al., "Per Hop Behavior Identification
             Codes," June 2001.

   [RFC3181] Herzog, S., "Signaled Preemption Priority Policy Element,"
             RFC 3181, October 2001.

   [RFC4124] Le Faucheur, F., et al., "Protocol Extensions for Support

Ash, et al.         <draft-ietf-nsis-qspec-23.txt>           [Page 50]

Internet Draft          QoS-NSLP QSPEC Template             January 2010


             of Diffserv-aware MPLS Traffic Engineering," RFC 4124, June
             2005.

   [RFC4412] Schulzrinne, H., Polk, J., "Communications Resource
             Priority for the Session Initiation Protocol(SIP)," RFC
             4412, February 2006.

   [RFC4506] Eisler, M., "XDR: External Data Representation Standard,"
             RFC 4506, May 2006.

   [Y.1541]  ITU-T Recommendation Y.1541, "Network Performance
             Objectives for IP-Based Services," February 2006.

   [Y.2171]  ITU-T Recommendation Y.2171, "Admission Control Priority
             Levels in Next Generation Networks," September 2006.

11. Informative References

   [COMPOSITION] Morton, A.,Stephan, E., "Spacial Composition of
             Metrics," work in progress.

   [DQOS]    Cablelabs, "PacketCable Dynamic Quality of Service
             Specification," CableLabs Specification
             PKT-SP-DQOS-I12-050812, August 2005.

   [EMERGENCY-RSVP] Le Faucheur, F., et. al., "Resource ReSerVation
             Protocol (RSVP) Extensions for Emergency Services," work in
             progress.

   [G.711]   ITU-T Recommendation G.711, "Pulse code modulation (PCM) of
             voice frequencies," November 1988.

   [IEEE754] Institute of Electrical and Electronics Engineers, "IEEE
             Standard for Binary Floating-Point Arithmetic," ANSI/IEEE
             Standard 754-1985, August 1985.

   [CL-QOSM] Kappler, C., "A QoS Model for Signaling IntServ
             Controlled-Load Service with NSIS," work in progress.

   [DSCP-REGISTRY] http://www.iana.org/assignments/dscp-registry.

   [NETWORK-OCTET-ORDER] Wikipedia, "Endianness,"
             http://en.wikipedia.org/wiki/Endianness.

   [PHBID-CODES-REGISTRY] http://www.iana.org/assignments/phbid-codes.


   [Q.2630]  ITU-T Recommendation Q.2630.3: "AAL Type 2 Signaling
             Protocol - Capability Set 3," September 2003.

   [RFC1701] Hanks, S., et. al., "Generic Routing Encapsulation (GRE),"
             RFC 1701, October 1994.

Ash, et al.         <draft-ietf-nsis-qspec-23.txt>           [Page 51]

Internet Draft          QoS-NSLP QSPEC Template             January 2010



   [RFC1702] Hanks, S., et. al., "Generic Routing Encapsulation over
             IPv4 Networks," RFC 1702, October 1994.

   [RFC2003] Perkins, C., "IP Encapsulation within IP," RFC 2003,
             October 1996.

   [RFC2004] Perkins, C., "Minimal Encapsulation within IP," RFC 2004,
             October 1996.

   [RFC2205] Braden, B., et al., "Resource ReSerVation Protocol (RSVP)
             -- Version 1 Functional Specification," RFC 2205, September
             1997.

   [RFC2473] Conta, A., Deering, S., "Generic Packet Tunneling in IPv6
             Specification," RFC 2473, December 1998.

   [RFC2474] Nichols, K., et al., "Definition of the Differentiated
             Services Field (DS Field) in the IPv4 and IPv6 Headers,"
             RFC 2474, December 1998.

   [RFC2475] Blake, S., et al., "An Architecture for Differentiated
             Services", RFC 2475, December 1998.

   [RFC2597] Heinanen, J., et al., "Assured Forwarding PHB Group," RFC
             2597, June 1999.

   [RFC2697] Heinanen, J., et al., "A Single Rate Three Color Marker,"
             RFC 2697, September 1999.

   [RFC2997] Bernet, Y., et al., "Specification of the Null Service
             Type," RFC 2997, November 2000.

   [RFC3290] Bernet, Y., et al., "An Informal Management Model for
             Diffserv Routers," RFC 3290, May 2002.

   [RFC3393] Demichelis, C., Chimento, P., "IP Packet Delay Variation
             Metric for IP Performance Metrics (IPPM), RFC 3393,
             November 2002.

   [RFC3550] Schulzrinne, H., et. al., "RTP: A Transport Protocol for
             Real-Time Applications," RFC 3550, July 2003.

   [RFC3564] Le Faucheur, F., et al., "Requirements for Support of
             Differentiated Services-aware MPLS Traffic Engineering,"
             RFC 3564, July 2003.

   [RFC4213] Nordmark, E., Gilligan, R., "Basic Transition Mechanisms
             for IPv6 Hosts and Routers," RFC 4213, October 2005.

   [RFC4301] Kent, S., Seo, K., "Security Architecture for the Internet
             Protocol," RFC 4301, December 2005.

Ash, et al.         <draft-ietf-nsis-qspec-23.txt>           [Page 52]

Internet Draft          QoS-NSLP QSPEC Template             January 2010



   [RFC4303] Kent, S., "IP Encapsulating Security Payload (ESP)," RFC
             4303, December 2005.

   [RFC5226] Narten, T., Alvestrand, H., "Guidelines for Writing an
             IANA Considerations Section in RFCs," RFC 5226, May 2008.

   [RFC5481] Morton, A., Claise, B., "Packet Delay Variation
                  Applicability Statement," RFC 5481, March 2009.

   [RMD-QOSM] Bader, A., et al., "RMD-QOSM - The Resource Management
             in Diffserv QOS Model," work in progress.

   [VERTICAL-INTERFACE] Dolly, M., Tarapore, P., Sayers, S., "Discussion
             on Associating of Control Signaling Messages with Media
             Priority Levels," T1S1.7 & PRQC, October 2004.

   [Y.1540]  ITU-T Recommendation Y.1540, "Internet Protocol Data
             Communication Service - IP Packet Transfer and Availability
             Performance Parameters," December 2002.

   [Y.1541-QOSM] Ash, J., et al., "Y.1541-QOSM -- Y.1541 QoS Model for
             Networks Using Y.1541 QoS Classes," work in progress.

12. Authors' Addresses

   Gerald Ash (Editor)
   AT&T
   Email: gash5107@yahoo.com

   Attila Bader (Editor)
   Traffic Lab
   Ericsson Research
   Ericsson Hungary Ltd.
   Laborc u. 1 H-1037
   Budapest Hungary
   Email: Attila.Bader@ericsson.com

   Cornelia Kappler (Editor)
   deZem GmbH
   Knesebeckstr. 86/87
   10623 Berlin
   Germany
   Email: cornelia.kappler@googlemail.com

   David R. Oran (Editor)
   Cisco Systems, Inc.
   7 Ladyslipper Lane
   Acton, MA 01720, USA
   Email:  oran@cisco.com

Appendix A. Mapping of QoS Desired, QoS Available and QoS Reserved of

Ash, et al.         <draft-ietf-nsis-qspec-23.txt>           [Page 53]

Internet Draft          QoS-NSLP QSPEC Template             January 2010


NSIS onto AdSpec, TSpec and RSpec of RSVP IntServ

   The union of QoS Desired, QoS Available and QoS Reserved can provide
   all functionality of the objects specified in RSVP IntServ, however
   it is difficult to provide an exact mapping.

   In RSVP, the Sender TSpec specifies the traffic an application is
   going to send (e.g. TMOD). The AdSpec can collect path
   characteristics (e.g. delay). Both are issued by the sender. The
   receiver sends the FlowSpec which includes a Receiver TSpec
   describing the resources reserved using the same parameters as the
   Sender TSpec, as well as a RSpec which provides additional IntServ
   QoS Model specific parameters, e.g. Rate and Slack.

   The RSVP TSpec/AdSpec/RSpec seem quite tailored to receiver-initiated
   signaling employed by RSVP, and the IntServ QoS Model. E.g. to the
   knowledge of the authors it is not possible for the sender to specify
   a desired maximum delay except implicitly and mutably by seeding the
   AdSpec accordingly. Likewise, the RSpec is only meaningfully sent in
   the receiver-issued RSVP RESERVE message. For this reason our
   discussion at this point leads us to a slightly different mapping of
   necessary functionality to objects, which should result in more
   flexible signaling models.

Appendix B. Example of TMOD Parameter Encoding

   An example VoIP application that uses RTP [RFC3550] and the G.711
   Codec [G.711] the TMOD-1 parameter could be set as follows:

   In the simplest case the Minimum Policed Unit m is the sum of the
   IP-, UDP- and RTP- headers + payload. The IP header in the IPv4 case
   has a size of 20 octets (40 octets if IPv6 is used). The UDP header
   has a size of 8 octets and RTP uses a 12 octet header. The G.711
   Codec specifies a bandwidth of 64 kbit/s (8000 octets/s). Assuming
   RTP transmits voice datagrams every 20ms, the payload for one
   datagram is 8000 octets/s * 0.02 s = 160 octets.

   IPv4+UDP+RTP+payload: m=20+8+12+160 octets = 200 octets
   IPv6+UDP+RTP+payload: m=40+8+12+160 octets = 220 octets

   The Rate r specifies the amount of octets per second. 50 datagrams
   Are sent per second.

   IPv4: r = 50 1/s * m = 10,000 octets/s
   IPv6: r = 50 1/s * m = 11,000 octets/s

   The bucket size b specifies the maximum burst. In this example a
   burst of 10 packets is used.

   IPv4: b = 10 * m = 2000 octets
   IPv6: b = 10 * m = 2200 octets


Ash, et al.         <draft-ietf-nsis-qspec-23.txt>           [Page 54]

Internet Draft          QoS-NSLP QSPEC Template             January 2010


   A number of extra headers (e.g. for encapsulation) may be included
   into the datagram. A non exhaustive list is given below. For
   additional headers m, r and b have to be set accordingly.

   Protocol Header Size
   --------------------------+-----------
   GRE [RFC1701]             | 8 octets
   GREIP4 [RFC1702]          | 4-8 octets
   IP4INIP4 [RFC2003]        | 20 octets
   MINENC [RFC2004]          | 8-12 octets
   IP6GEN [RFC2473]          | 40 octets
   IP6INIP4 [RFC4213]        | 20 octets
   IPSec [RFC4301, RFC4303]  | variable
   --------------------------+-----------

Appendix C. Change History & Open Issues

   This appendix should be removed by the RFC editor before publication.

C.1 Change History (since Version -14)

   Version -14:

   - Section 4.3.3 added text that QOSM specifications SHOULD NOT define
     new RMF functions
   - Section 5.1 added text that both mechanisms can be used
     simultaneously: a) tunneling a QSPEC through a local domain and b)
     defining a local QSPEC and encapsulating the initiator QSPEC
   - Section 4.1 added text that signaling functionality is only defined
     by the QoS NSLP document
   - Section 4.1 added text that QOSMs are free to extend QSPECs by
     adding parameters but are not permitted to reinterpret or redefine
     the standard QSPEC parameters specified in this document

   Version -15:

   - editorial revisions made to Sections 4.1, 4.3.3, 5.3.1, 5.3.2, and
     5.3.3 according to agreements on NSIS discussion list archive.

   Version -16:

   - QSPEC Types: additional QSPEC Types can be defined per IANA
     Considerations Section (already in place); QSPEC Type = 0 is
     default
   - Initiator/Local QSPEC bit added
   - various editorial fixes: DSCP parameter encoding; various edits
     carry over from QSPEC-1 parameter removal; QSPEC version number
     edits & additional error code

   Version -17:
   - QSPEC Header format: added Length field


Ash, et al.         <draft-ietf-nsis-qspec-23.txt>           [Page 55]

Internet Draft          QoS-NSLP QSPEC Template             January 2010


   Version -18:
   - clarified handling of Traffic Handling Directives in QoS Available
     in Sec. 4.3.3
   - classified Priority Parameters as Traffic Handling Directives
     (Previously and erroneously were classified as Constraint
     Parameters)
   - added units to TMOD parameter in 6.2.1
   - fixed error in possible object combination for Resource Queries in
   Sec 6.1
   - streamlined usage of QSPEC Type and added terminology

   Version -19:
   - changes made per NSIS chair review (as specified on list)

   Version -20:
   - changes made to Section 5.2.9 (Admission Priority) as specified on
     List

   Version -21:
   - added example of TMOD parameter encoding (Appendix B)
   - eliminated IANA registry for DSTE class types

   Version -22:
   - incorporated responses to AD review comments (see
     http://www.ietf.org/mail-archive/web/nsis/current/msg08601.html)

   Version -23:
   - incorporated responses to Gen-Art and IANA review comments (see
     http://www.ietf.org/mail-archive/web/nsis/current/msg08616.html)

C.2 Open Issues

   None.

Ash, et al.         <draft-ietf-nsis-qspec-23.txt>           [Page 56]

Html markup produced by rfcmarkup 1.109, available from https://tools.ietf.org/tools/rfcmarkup/