MPLS Working Group                                    E. Bellagamba, Ed.
Internet-Draft                                              L. Andersson, Ed. Andersson
Intended status: Standards Track                                Ericsson
Expires: June 13, September 11, 2011                           P. Skoldstrom, Ed.
                                                                Acreo AB
                                                                 D. Ward
                                                                J. Drake
                                                                 Juniper
                                                       December
                                                          March 10, 2010 2011

  Configuration of pro-active MPLS-TP Operations, Administration, and
               Maintenance (OAM) Functions Using LSP Ping
              draft-ietf-mpls-lsp-ping-mpls-tp-oam-conf-00
              draft-ietf-mpls-lsp-ping-mpls-tp-oam-conf-01

Abstract

   This specification describes the configuration of pro-active MPLS-TP
   Operations, Administration, and Maintenance (OAM) Functions for a
   given LSP using a common set of TLVs that is carried on LSP Ping.

Status of this Memo

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Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  3
     1.1.  Contributing Authors  . . . . . . . . . . . . . . . . . . . 3
     1.2.  Requirements Language  . . . . . . . . . . . . . . . . . . .  3
     1.3.
     1.2.  Overview of BFD OAM operation  . . . . . . . . . . . . . . .  4
   2.  Overview of MPLS OAM for Transport Applications  . . . . . . . .  4
   3.  Theory of Operations . . . . . . . . . . . . . . . . . . . . .  5
     3.1.  MPLS OAM Configuration Operation Overview  . . . . . . . . .  5
     3.2.  TLVs structure  OAM Functions TLV  . . . . . . . . . . . . . . . . . . . .  7
       3.2.1.  BFD Configuration sub-TLV  . . . 5
     3.3. . . . . . . . . . . .  8
         3.2.1.1.  Local Discriminator sub-TLV  . . . . . . . . . . . 10
         3.2.1.2.  Negotiation Timer Parameters sub-TLV . . . . . . . 10
         3.2.1.3.  MPLS OAM SOURCE MEP-ID TLV for LSP Ping sub-TLV . . . . . . . . . . 6
   4. 12
         3.2.1.4.  BFD Authentication sub-TLV . . . . . . . . . . . . 12
       3.2.2.  MPLS OAM configuration errors PM Loss sub-TLV . . . . . . . . . . . . . . . 13
       3.2.3.  MPLS OAM PM Delay sub-TLV  . . 6
   5.  Security . . . . . . . . . . . . 14
       3.2.4.  MPLS OAM FMS sub-TLV . . . . . . . . . . . . . . . . . 15
     3.3.  IANA Considerations  . . . . . . . . . . . . . . . . . . . 16
   4.  OAM configuration errors . 7
   6.  References . . . . . . . . . . . . . . . . . . 16
   5.  Security Considerations  . . . . . . . . 7
     6.1.  Normative . . . . . . . . . . . 17
   6.  References . . . . . . . . . . . . . . . . . . . 7
     6.2.  Informative . . . . . . . 17
     6.1.  Normative References . . . . . . . . . . . . . . . . . . 8
   Appendix A.  Additional Stuff . 17
     6.2.  Informative References . . . . . . . . . . . . . . . . . . 9 18
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 9 19

1.  Introduction

   This document describes the configuration of pro-active MPLS-TP
   Operations, Administration, and Maintenance (OAM) Functions for a
   given LSP using a common set of TLVs that can be carried on either
   RSVP-TE [RFC3209] or in LSP Ping [BFD-Ping].  In particular
   it specifies the mechanisms necessary to establish MPLS-TP OAM
   entities monitoring an LSP and defines information elements and
   procedures to configure pro-active MPLS OAM functions.
   Initialization and control of on-
   demand on-demand MPLS OAM functions are
   expected to be carried out by directly accessing network nodes via a
   management interface; hence configuration and control of on-demand
   OAM functions are out-of-scope for this document.

   Because the Transport Profile of MPLS, by definition [RFC5654], must
   be capable of operating without a control plane, there are two
   options for in-band OAM: by using an NMS or by using LSP-Ping LSP Ping if a
   control plane is not instantiated.

   Pro-active MPLS OAM is based on the Bidirectional Forwarding
   Detection (BFD) protocol [BFD]. [RFC5880].  Bidirectional Forwarding
   Detection (BFD), as described in [BFD], [RFC5880], defines a protocol that
   provides low- overhead, short-duration detection of failures in the
   path between two forwarding engines, including the interfaces, data
   link(s), and to the extent possible the forwarding engines
   themselves.  BFD can be used to track the liveliness and detect data
   plane failures of MPLS-TP point-to-point and might also be extended
   to p2mp connections.

   MPLS Transport Profile (MPLS-TP) describes a profile of MPLS that
   enables operational models typical in transport networks, while
   providing additional OAM, survivability and other maintenance
   functions not currently supported by MPLS.  [MPLS-TP-OAM-REQ]  [RFC5860] defines the
   requirements for the OAM functionality of MPLS-TP.

   BFD has been chosen to be the basis of pro-active MPLS-TP OAM
   functions.  MPLS-TP OAM extensions for transport applications, for
   which this document specifies the configuration, are specified in
   [BFD-CCCV], [MPLS-PM], and [MPLS-FMS].

1.1.  Contributing Authors

   The editors gratefully acknowledge the contribution of John Drake.

1.2.  Requirements Language

   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].

1.3.

1.2.  Overview of BFD OAM operation

   BFD is a simple hello protocol that in many respects is similar to
   the detection components of well-known routing protocols.  A pair of
   systems transmits BFD packets periodically over each path between the
   two systems, and if a system stops receiving BFD packets for long
   enough, some component in that particular bidirectional path to the
   neighboring system is assumed to have failed.  Systems may also
   negotiate to not send periodic BFD packets in order to reduce
   overhead.

   A path is only declared to be operational when two-way communication
   has been established between systems, though this does not preclude
   the use of unidirectional links to support bidirectional paths (co-
   routed or bidirectional or associated bidirectional).

   Each system estimates how quickly it can send and receive BFD packets
   in order to come to an agreement with its neighbor about how rapidly
   detection of failure will take place.  These estimates can be
   modified in real time in order to adapt to unusual situations.  This
   design also allows for fast systems on a shared medium with a slow
   system to be able to more rapidly detect failures between the fast
   systems while allowing the slow system to participate to the best of
   its ability.  However, in some cases one may want to configure these
   timers manually, in those cases the TLVs defined in this document can
   be used.

   The ability of each system to control the BFD packet transmission
   rate in both directions provides a mechanism for congestion control,
   particularly when BFD is used across multiple network hops.

   As recommended in [BFD-CCCV], the BFD tool needs to be extended for
   the proactive CV functionality by the addition of an unique
   identifier in order to meet the requirements.  The document in [BFD-
   CCCV] specifies the BFD extension and behavior to meet the
   requirements for MPLS-TP proactive Continuity Check and Connectivity
   Verification functionality and the RDI functionality as defined in
   [MPLS-TP-OAM-REQ].
   [RFC5860].

2.  Overview of MPLS OAM for Transport Applications

   [MPLS-TP-OAM-FWK] describes how MPLS OAM mechanisms are operated to
   meet transport requirements outlined in [MPLS-TP-OAM-REQ]. [RFC5860].

   [BFD-CCCV] specifies two BFD operation modes: 1) "CC mode", which
   uses periodic BFD message exchanges with symmetric timer settings,
   supporting Continuity Check, 2) "CV/CC mode" which sends unique
   maintenance entity identifiers in the periodic BFD messages
   supporting Connectivity Verification as well as Continuity Check.

   [MPLS-PM] specifies mechanisms for performance monitoring of LSPs, in
   particular it specifies loss and delay measurement OAM functions.

   [MPLS-FMS] specifies fault management signals with which a server LSP
   can notify client LSPs about various fault conditions to suppress
   alarms or to be used as triggers for actions in the client LSPs.  The
   following signals are defined: Alarm Indication Signal (AIS), Link
   Down Indication (LDI) and Locked Report (LKR).  To indicate client
   faults associated with the attachment circuits Client Signal Failure
   Indication (CSF) can be used.  CSF is described in [MPLS-TP-OAM-FWK]
   and in the context of this document is for further study.

   [MPLS-TP-OAM-FWK] describes the mapping of fault conditions to
   consequent actions.  Some of these mappings may be configured by the
   operator, depending on the application of the LSP.  The following
   defects are identified: Loss Of Continuity (LOC), Misconnectivity,
   MEP Misconfiguration and Period Misconfiguration.  Out of these
   defect conditions, the following consequent actions may be
   configurable: 1) whether or not the LOC defect should result in
   blocking the outgoing data traffic; 2) whether or not the "Period
   Misconfiguration defect" should result a signal fail condition.

3.  Theory of Operations

3.1.  MPLS OAM Configuration Operation Overview

   Refer to section 3.1 of

   LSP Ping, or alternatively RSVP-TE [RSVP-TE CONF] for the applicability
   scenarios description and their related configurations and
   mechanisms.  In fact, each of them CONF], can be completely reused in case
   of LSP Ping configuration as well as already done for RSVP-TE.

   The only exception is that used to
   simply establish (i.e., bootstrap) a BFD session or it can
   selectively enable and configure all pro-active MPLS OAM functions.
   For this specification, BFD MUST be run in asynchronous mode and both
   sides should be in active mode.

   In the simplest scenario LSP Ping needs Ping, or alternatively RSVP-TE [RSVP-TE
   CONF], is used only to bootstrap the BFD session.  In this case the
   initiating node includes an extra "OAM Functions TLV" in the LSP Echo
   Request message it sends to the receiving node at the other end of
   the LSP.  This TLV includes a number of flags that are used to carry
   indicate what types of OAM should be enabled as well as sub-TLVs
   containing the
   information required for parameters to be used with corresponding OAM
   functions.  In this simple case it has the "CV/CC mode" CC OAM [BFD-CCCV] Functions flag is
   set, and defined
   in [MPLS-TP-IDENTIF].  Such information a "BFD Configuration sub-TLV" is supplied included.  The sub-TLV
   carries a "Local Discriminator sub-TLV" with the discriminator value
   selected by the initiating node for the BFD session associated with
   the LSP.  The N flag in the "BFD Configuration sub-TLV" MUST be set
   to enable timer negotiation/re-negotiation via BFD Control Messages.

   The receiving node MUST use the Local Discriminator value it receives
   to identify the remote end of the BFD session.  The receiving node
   must send a LSP Echo Response message to the initiating node that
   includes an additional
   sub-TLV "OAM Functions TLV" containing the same values as defined it
   received, except for the "Local Discriminator sub-TLV", which
   contains the local discriminator value selected by the receiving node
   for the BFD session.

   Timer negotiation is performed in section 3.3.

3.2.  TLVs structure subsequent BFD control messages.
   This operation is similar to LSP Ping follows based bootstrapping described
   in [RFC5884].

   If timer negotiation is to be done using the same TLV structure TLVs defined for RSVP-TE in
   [RSVP-TE CONF] from section 3.2 to section 3.6. this
   document rather than with BFD Control packets, the N flag of the "BFD
   Configuration sub-TLV" MUST be cleared and a "Timer Negotiation
   Parameters sub-TLV" MUST be present in the "BFD Configuration sub-
   TLV".  In addition, an extra TLV this case, there are two configuration options, symmetric
   and asymmetric.  If symmetric configuration is defined used, the S flag in
   "BFD Configuration sub-TLV" MUST be set.  If the flag is cleared, the
   configuration is completed asymmetrically in the two directions.
   Section 3.3.1 includes a detailed explanation of such configuration.

   In the case of the "CV/CC mode" OAM [BFD-CCCV], the "CV" flag MUST be
   set in addition to the CC flag in the "BFD Configuration sub-TLV".
   The information required to support this functionality is defined in
   [MPLS-TP-IDENTIF].  If the "CV" flag is set the "BFD Configuration
   sub-TLV" MUST include a "MPLS OAM SOURCE MEP-ID sub-TLV" containing
   these parameters.

   When BFD Control packets are transported in the G-ACh they are not
   protected by any end-to-end checksum, only lower-layers are providing
   error detection/correction.  A single bit error, e.g. a flipped bit
   in the BFD State field could cause the receiving end to wrongly
   conclude that the link is down and thus trigger protection switching.
   To prevent this from happening the "BFD Configuration sub-TLV" has an
   Integrity flag that when set enables BFD Authentication using Keyed
   SHA1 with an empty key (all 0s) [RFC5880].  This would make every BFD
   Control packet carry an SHA1 hash of itself that can be used to
   detect errors.

   If BFD Authentication using a shared key / password is desired (i.e.
   actual authentication not only error detection) the "BFD
   Authentication sub-TLV" MUST be included in the "BFD Configuration
   sub-TLV".  The "BFD Authentication sub-TLV" is used to specify which
   authentication method that should be used and which shared key /
   password that should be used for this particular session.  How the
   key exchange is performed is out of scope of this document.

   Additional OAM functions may be configured by setting the appropriate
   flags in the "OAM Functions TLV", these include Performace
   Measurements (packet loss and packet delay) and Fault Management
   Signal handling.

   By setting the PM Loss flag in the "OAM Functions TLV" and including
   the "MPLS OAM PM Loss sub-TLV" one can configure the measurement
   interval and loss threshold values for triggering protection.

   Delay measurements are configured by setting PM Delay flag in the
   "OAM Functions TLV" and including the "MPLS OAM PM Loss sub-TLV" one
   can configure the measurement interval and the delay threshold values
   for triggering protection.

   To configure Fault Monitoring Signals and their refresh time the FMS
   flag in the "OAM Functions TLV" MUST be set and the "MPLS OAM FMS
   sub-TLV" included.

3.2.  OAM Functions TLV

   The "OAM Functions TLV" depicted below is carried as a TLV of the LSP
   Echo request/response messages.

    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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |  OAM Func. Type (16) (IANA)   |           Length              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |C|V|L|D|F|           OAM Function Flags                        |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   ~                           sub-TLVs                            ~
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   The "OAM Functions TLV" contains a number of flags indicating which
   OAM functions should be activated as well as OAM function specific
   sub-TLVs with configuration parameters for the particular function.

   Type: indicates a new type, the "OAM Functions TLV" (IANA to define,
   suggested value 16).

   Length: the length of the OAM Function Flags field including the
   total length of the sub-TLVs in octets.

   OAM Function Flags: a bitmap numbered from left to right as shown in
   the figure.

   These flags are defined in this document:

   OAM Function Flag bit#             Description
   ---------------------      ---------------------------
            0 (C)             Continuity Check (CC)
            1 (V)             Connectivity Verification (CV)
            2 (L)             Performance Monitoring/Loss (PM/Loss)
            3 (D)             Performance Monitoring/Delay (PM/Delay)
            4 (F)             Fault Management Signals (FMS)
            5-31              Reserved (set all to 0s)

   Sub-TLVs corresponding to the different flags are as follows:

      - "BFD Configuration sub-TLV", which MUST be included if the CC
      OAM Function flag is set.  This sub-TLV MUST carry a "BFD Local
      Discriminator sub-TLV" and a "Timer Negotiation Parameters sub-
      TLV" if the N flag is cleared.  If the CV flag is set, the CC flag
      MUST be set at the same time and a "MPLS OAM SOURCE MEP-ID sub-
      TLV" MUST be included in the "BFD Configuration sub-TLV".  It MAY
      carry a "BFD Authentication sub-TLV" if the I flag is set.  If the
      I flag is set but no "BFD Authentication sub-TLV" is included
      Keyed SHA1 with an empty key is used.

      - "MPLS OAM PM Loss sub-TLV", which MAY be included if the PM/Loss
      OAM Function flag is set.  If the "MPLS OAM PM Loss sub-TLV" is
      not included, default configuration values are used.

      - "MPLS OAM PM Delay sub-TLV", which MAY be included if the PM/
      Delay OAM Function flag is set.  If the "MPLS OAM PM Delay sub-
      TLV" is not included, default configuration values are used.

      - "MPLS OAM FMS sub-TLV", which MAY be included if the FMS OAM
      Function flag is set.  If the "MPLS OAM FMS sub-TLV" is not
      included, default configuration values are used.

3.2.1.  BFD Configuration sub-TLV

   The "BFD Configuration sub-TLV" (depicted below) is defined for BFD
   OAM specific configuration parameters.  The "BFD Configuration sub-
   TLV" is carried as a sub-TLV of the "OAM Functions TLV".

   This TLV accommodates generic BFD OAM information and carries sub-
   TLVs.

    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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |  BFD Conf. Type (1) (IANA)    |           Length              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |Vers.| PHB |N|S|      Reserved (set to all 0s)                 |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   ~                           sub TLVs                            ~
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type: indicates a new type, the "BFD Configuration sub-TLV" (IANA to
   define, suggested value 1).

   Length: indicates the length of the TLV including sub-TLVs but
   excluding the Type and Length field, in octets.

   Version: identifies the BFD protocol version.  If a node does not
   support a specific BFD version an error must be generated: "OAM
   Problem/Unsupported OAM Version".

   PHB: Identifies the Per-Hop Behavior (PHB) to be used for periodic
   continuity monitoring messages.

   BFD Negotiation (N): If set timer negotiation/re-negotiation via BFD
   Control Messages is enabled, when cleared it is disabled.

   Symmetric session (S): If set the BFD session MUST use symmetric
   timing values.

   Integrity (I): If set BFD Authentication MUST be enabled.  If the
   "BFD Configuration sub-TLV" does not include a "BFD Authentication
   sub-TLV" the authentication MUST use Keyed SHA1 with an empty pre-
   shared key (all 0s).

   The "BFD Configuration sub-TLV" MUST include the following sub-TLVs
   in the LSP Echo request message:

      - "Local Discriminator sub-TLV";

      - "Negotiation Timer Parameters sub-TLV" if N flag is cleared.

   The "BFD Configuration sub-TLV" MUST include the following sub-TLVs
   in the LSP Echo reply message:

      - "Local Discriminator sub-TLV;"

      - "Negotiation Timer Parameters sub-TLV" if:

         - N flag and S are cleared

         - N flag is cleared and S flag is set and a timing value higher
         than the one received needs to be used

   Reserved: Reserved for future specification and set to 0.

3.2.1.1.  Local Discriminator sub-TLV

   The "Local Discriminator sub-TLV" is carried as a sub-TLV of the "BFD
   Configuration sub-TLV" and is depicted below.

    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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |  Lcl. Discr. Type (1) (IANA)  |         Length (4)            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                       Local Discriminator                     |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type: indicates a new type, the "Local Discriminator sub-TLV" (IANA
   to define, suggested value 1).

   Length: indicates the TLV total length in octets.

   Local Discriminator: A unique, nonzero discriminator value generated
   by the transmitting system and referring to itself, used to
   demultiplex multiple BFD sessions between the same pair of systems.

3.2.1.2.  Negotiation Timer Parameters sub-TLV

   The "Negotiation Timer Parameters sub-TLV" is carried as a sub-TLV of
   the "BFD Configuration sub-TLV" and is depicted below.

    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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |  Timer Neg.  Type (2) (IANA)  |          Length (16)          |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |         Acceptable Min. Asynchronous TX interval              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |         Acceptable Min. Asynchronous RX interval              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |               Required Echo TX Interval                       |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |  Detect. Mult.|           Reserved  (set to all 0s)           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type: indicates a new type, the "Negotiation Timer Parameters sub-
   TLV" (IANA to define, suggested value 2).

   Length: indicates the length of the parameters in octets (16).

   Acceptable Min. Asynchronous TX interval: in case of S (symmetric)
   flag set in the "BFD Configuration" TLV, it expresses the desired
   time interval (in microseconds) at which the LER initiating the
   signaling intends to both transmit and receive BFD periodic control
   packets.  If the receiving edge LSR can not support such value, it is
   allowed to reply back with an interval greater than the one proposed.

   In case of S (symmetric) flag cleared in the "BFD Configuration sub-
   TLV", this field expresses the desired time interval (in
   microseconds) at which a edge LSR intends to transmit BFD periodic
   control packets in its transmitting direction.

   Acceptable Min. Asynchronous RX interval: in case of S (symmetric)
   flag set in the "BFD Configuration sub-TLV", this field MUST be equal
   to "Acceptable Min. Asynchronous TX interval" and has no additional
   meaning respect to the one described for "Acceptable Min.
   Asynchronous TX interval".

   In case of S (symmetric) flag cleared in the "BFD Configuration sub-
   TLV", it expresses the minimum time interval (in microseconds) at
   which edge LSRs can receive BFD periodic control packets.  In case
   this value is greater than the "Acceptable Min. Asynchronous TX
   interval" received from the other edge LSR, such edge LSR MUST adopt
   the interval expressed in this "Acceptable Min. Asynchronous RX
   interval".

   Required Echo TX Interval: the minimum interval (in microseconds)
   between received BFD Echo packets that this system is capable of
   supporting, less any jitter applied by the sender as described in

   [RFC5880] sect. 6.8.9.  This value is also an indication for the
   receiving system of the minimum interval between transmitted BFD Echo
   packets.  If this value is zero, the transmitting system does not
   support the receipt of BFD Echo packets.  If the receiving system can
   not support this value an error MUST be generated "Unsupported BFD TX
   rate interval".

   Detection time multiplier: The negotiated transmit interval,
   multiplied by this value, provides the Detection Time for the
   receiving system in Asynchronous mode.

   Reserved: Reserved for future specification and set to 0.

3.2.1.3.  MPLS OAM SOURCE MEP-ID sub-TLV

   The "MPLS OAM SOURCE MEP-ID sub-TLV" depicted below is carried as a
   sub-TLV of the "OAM Functions TLV".

    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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | Src MEP-ID  Type (3)  (IANA)  |        Length (8)             |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                         SRC NODE ID                           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |           TUNNEL ID           |           LSP ID              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type: indicates a new type, the "MPLS OAM SOURCE MEP-ID sub-TLV"
   (IANA to define, suggested value 3).

   Length: indicates the length of the parameters in octets (8).

   SRC NODE ID: 32-bit node identifier as defined in [MPLS-TP-IDENTIF].

   TUNNEL ID: a 16-bit unsigned integer unique to the node as defined in
   [MPLS-TP-IDENTIF].

   LSP ID: a 16-bit unsigned integer unique within the Tunnel_ID as
   defined in [MPLS-TP-IDENTIF].

3.2.1.4.  BFD Authentication sub-TLV

   The "BFD Authentication sub-TLV" is carried as a sub-TLV of the "BFD
   Configuration sub-TLV" and is depicted below.

    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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |    BFD Auth. Type (4) (IANA)  |          Length = 8           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |   Auth Type   |  Auth Key ID  |         Reserved (0s)         |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type: indicates a new type, the "BFD Authentication sub-TLV" (IANA to
   define).

   Length: indicates the TLV total length in octets. (8)

   Auth Type: indicates which type of authentication to use.  The same
   values as are defined in section 4.1 of [RFC5880] are used.

   Auth Key ID: indicates which authentication key or password
   (depending on Auth Type) should be used.  How the key exchange is
   performed is out of scope of this document.

   Reserved: Reserved for future specification and set to 0.

3.2.2.  MPLS OAM PM Loss sub-TLV

   The "MPLS OAM PM Loss sub-TLV" depicted below is carried as a sub-TLV
   of the "OAM Functions TLV".

    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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |  PM Loss Type (2) (IANA)      |          Length (12)          |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |Vers.|E|C|     |           Reserved  (set to all 0s)     | PHB |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                    Measurement Interval                       |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                      Loss Threshold                           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type: indicates a new type, the "MPLS OAM PM Loss sub-TLV" (IANA to
   define, suggested value 2).

   Length: indicates the length of the parameters in octets (12).

   Version: indicates the Loss measurement protocol version.

   Configuration Flags:

      - E: exclude from the Loss Measurement all G-ACh messages

      - C: require the use of a counter in the "Querier Context" field
      described in [MPLS-PM]

      - Remaining bits: Reserved for future specification and set to 0.

   PHB: identifies the per-hop behavior of packets with loss
   information.

   Measurement Interval: the time interval (in microseconds) at which
   Loss Measurement query messages MUST be sent on both directions.  If
   the edge LSR receiving the Path message can not support such value,
   it can reply back with a higher interval.

   Loss Threshold: the threshold value of lost packets over which
   protections MUST be triggered.

3.2.3.  MPLS OAM PM Delay sub-TLV

   The "MPLS OAM PM Delay sub-TLV" depicted below is carried as a sub-
   TLV of the "OAM Functions TLV".

    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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |  PM Delay Type (3) (IANA)     |          Length (12)          |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |Vers.| Flags   |           Reserved  (set all to 0)      | PHB |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                    Measurement Interval                       |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                      Delay Threshold                          |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type: indicates a new type, the "MPLS OAM SOURCE MEP-ID TLV" in
   order PM Delay sub-TLV" (IANA to supply
   define, suggested value 3).

   Length: indicates the information needed for length of the Connectivity
   Verification functionality.  In fact, RSVP-TE does not need such TLV
   because it already encodes this information parameters in other mandatory
   objects already included octets (12).

   Version: indicates the Delay measurement protocol version.

   Configuration Flags:

      - E: exclude from the Loss Measurement all G-ACh messages
      - C: require the use of a counter in its messages.

   The MPLS OAM SOURCE MEP-ID TLV is intended to be inserted the "Querier Context" field
      described in [MPLS-PM]

      - Remaining bits: Reserved for future specification and set to 0.

   PHB: - identifies the
   scope per-hop behavior of packets with delay
   information.

   Measurement Interval: the "OAM configuration TLV" together time interval (in microseconds) at which
   Delay Measurement query messages MUST be sent on both directions.  If
   the edge LSR receiving the Path message can not support such value,
   it can reply back with a higher interval.

   Delay Threshold: the othe sub-TLV threshold value of measured delay (in
   microseconds) over which protections MUST be triggered.

   [Author's note: TBD if we want to include the timestamp format
   negotiation as defined in [RSVP-TE CONF] section 3.2.

3.3. [MPLS-PM] 4.2.5.]

3.2.4.  MPLS OAM SOURCE MEP-ID TLV for LSP Ping FMS sub-TLV

   The "MPLS OAM SOURCE MEP-ID TLV for LSP Ping" FMS sub-TLV" depicted below is carried as a sub-TLV of
   the "OAM Configuration TLV" in case LSP Ping
   is used. Functions TLV".

    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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | Fault mgmt Type (6) (4) (IANA)    |        Length = 12 (8)             |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                         SRC NODE ID
   |A|D|L|C|                Reserved (set to all 0s)       |E| PHB |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |           TUNNEL ID           |           LSP ID                      Refresh Timer                            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type: indicates a new type, the "MPLS OAM SOURCE MEP-ID" FMS sub-TLV" (IANA to
   define).
   define, suggested value 4).

   Length: indicates the TLV total length of the parameters in octets.

   SRC NODE ID: 32-bit node identifier octets (8).

   Signal Flags: are used to enable the following signals:

      - A: Alarm Indication Signal (AIS) as defined described in [MPLS-TP-IDENTIF].

   TUNNEL ID: [MPLS-FMS]

      - D: Link Down Indication (LDI) as described in [MPLS-FMS]

      - L: Locked Report (LKR) as described in [MPLS-FMS]
      - C: Client Signal Failure (CSF) as described in [MPLS-CSF]

      - Remaining bits: Reserved for future specification and set to 0.

   Configuration Flags:

      - E: used to enable/disable explicitly clearing faults

      - PHB: identifies the per-hop behavior of packets with fault
      management information

   Refresh Timer: indicates the refresh timer (in microseconds) of fault
   indication messages.  If the edge LSR receiving the Path message can
   not support such value, it can reply back with a 16-bit unsigned integer unique higher interval.

3.3.  IANA Considerations

   This document specifies the following new TLV types:

      - "OAM Functions" type: 16;

   sub-TLV types to the node as defined be carried in
   [MPLS-TP-IDENTIF].

   LSP ID: a 16-bit unsigned integer unique within the Tunnel_ID as
   defined "OAM Functions TLV":

      - "BFD Configuration" type: 1;

      - "MPLS OAM PM Loss" type: 2;

      - "MPLS OAM PM Delay" type: 3;

      - "MPLS OAM FMS" type: 4.

   sub-TLV types to be carried in [MPLS-TP-IDENTIF]. the "BFD Configuration sub-TLV":

      - "Local Discriminator" type: 1;

      - "Negotiation Timer Parameters" type: 2;

      - "MPLS OAM SOURCE MEP-ID" type: 3.

      - "BFD Authentication" sub-TLV type: 4.

4.  BFD  OAM configuration errors

   In addition to error values specified in [OAM-CONF-FWK] and [ETH-OAM]
   this

   This document defines the following values for the "OAM Problem"
   Error Code: specifies additional Return Codes to LSP Ping:

      - "MPLS OAM Unsupported Functionality"; Functionality" (IANA to assign, suggested
      value 16);

      - "OAM Problem/Unsupported TX rate interval". interval" (IANA to assign,
      suggested value 17.

5.  Security Considerations

   The signaling of OAM related parameters and the automatic
   establishment of OAM entities introduces additional security
   considerations to those discussed in [RFC3473].  In particular, a
   network element could be overloaded, if an attacker would request
   liveliness monitoring, with frequent periodic messages, for a high
   number of LSPs, targeting a single network element.

   Security aspects will be covered in more detailed in subsequent
   versions of this document.

6.  References

6.1.  Normative References

   [BFD]      Katz, D. and D. Ward, "Bidirectional Forwarding
              Detection", 2009, <draft-ietf-bfd-base>.

   [MPLS-CSF]
              He, J. and H. J., Li, H., and E. Bellagamba, "Indication of Client
              Failure in MPLS-TP", 2009, 2010, <draft-he-mpls-tp-csf>.

   [MPLS-FMS]
              Swallow, G., Fulignoli, A., and M. Vigoureux, M., Boutros, S.,
              and D. Ward, "MPLS Fault Management OAM", 2009, <draft-sfv-mpls-tp-fault>.
              <draft-ietf-mpls-tp-fault>.

   [MPLS-PM]  Bryant, S. and D. Frost, "Packet Loss and Delay
              Measurement for the MPLS Transport Profile", 2009,
              <draft-frost-mpls-tp-loss-delay>.

   [MPLS-TP-IDENTIF]
              Bocci, M. 2010,
              <draft-ietf-mpls-tp-loss-delay>.

   [MPLS-PM-Profile]
              Bryant, S. and G. Swallow, "MPLS-TP Identifiers", 2009,
              <draft-swallow-mpls-tp-identifiers>.

   [MPLS-TP-OAM-REQ]
              Vigoureux, M., Ward, D., D. Frost, "A Packet Loss and M. Betts, "Requirements Delay
              Measurement Profile for
              OAM in MPLS MPLS-based Transport Networks", 2009,
              <draft-ietf-mpls-tp-oam-requirements>.
              2010, <draft-ietf-mpls-tp-loss-delay-profile>.

   [MPLS-TP-IDENTIF]
              Bocci, M., Swallow, G., and E. Gray, "MPLS-TP
              Identifiers", 2010, <draft-ietf-mpls-tp-identifiers>.

   [OAM-CONF-FWK]
              Takacs, A., Fedyk, D., and J. van He, "OAM Configuration
              Framework for GMPLS RSVP-TE", 2009,
              <draft-ietf-ccamp-oam-configuration-fwk>.

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

   [RFC3471]  Berger, L., "Generalized Multi-Protocol Label Switching
              (GMPLS) Signaling Functional Description", RFC 3471,
              January 2003.

   [RFC5586]  Bocci, M., Vigoureux, M., and S. Bryant, "MPLS Generic
              Associated Channel", RFC 5586, June 2009.

   [RFC5654]  Niven-Jenkins, B., Brungard, D., Betts, M., Sprecher, N.,
              and S. Ueno, "Requirements of an MPLS Transport Profile",
              RFC 5654, September 2009.

   [RFC5860]  Vigoureux, M., Ward, D., and M. Betts, "Requirements for
              Operations, Administration, and Maintenance (OAM) in MPLS
              Transport Networks", RFC 5860, May 2010.

   [RFC5880]  Katz, D. and D. Ward, "Bidirectional Forwarding Detection
              (BFD)", RFC 5880, June 2010.

   [RSVP-TE CONF]
              Bellagamba, E., Ward, D., Andersson, L., and P.
              Skoeldstroem,
              Skoldstrom, "Configuration of pro-active MPLS-TP
              Operations, Administration, and Maintenance (OAM)
              Functions Using RSVP-TE", 2010,
              <draft-ietf-ccamp-rsvp-te-mpls-tp-oam-ext>.

6.2.  Informative References

   [BFD-CCCV]
              Fulignoli, A., Boutros, S.,
              Allan, D., Swallow, G., and M. Vigoreux, "MPLS-TP BFD
              for Proactive CC-CV J. Drake, "Proactive
              Connectivity Verification, Continuity Check and RDI", 2009,
              <draft-asm-mpls-tp-bfd-cc-cv>. Remote
              Defect indication for MPLS Transport Profile", 2010,
              <draft-ietf-mpls-tp-bfd-cc-cv-rdi>.

   [BFD-Ping]
              Bahadur, N., Aggarwal, R., Ward, D., Nadeau, T., Sprecher,
              N., and Y. Weingarten, "LSP-Ping "LSP Ping and BFD encapsulation
              over ACH", 2009,
              <draft-nitinb-mpls-tp-lsp-ping-bfd-procedures-02>. 2010,
              <draft-ietf-mpls-tp-lsp-ping-bfd-procedures-02>.

   [ETH-OAM]  Takacs, A., Gero, B., Fedyk, D., Mohan, D., and D. Long,
              "GMPLS RSVP-TE Extensions for Ethernet OAM", 2009,
              <draft-ietf-ccamp-rsvp-te-eth-oam-ext>.

   [LSP Ping]
              Kompella, K. and G. Swallow, "Detecting Multi-Protocol
              Label Switched (MPLS) Data Plane Failures", 2006, <RFC
              3479>.

   [MPLS-TP OAM Analysis]
              Sprecher, N., Nadeau, T., van Helvoort, H., and Weingarten, Y., and E. Bellagamba, "MPLS-TP
              OAM Analysis", 2006,
              <draft-sprecher-mpls-tp-oam-analysis>.

   [MPLS-TP-FWK] 2011, <draft-ietf-mpls-tp-oam-analysis>.

   [MPLS-TP-OAM-FWK]
              Bocci, M., Bryant, S., Frost, D., M. and L. Levrau, "OAM
              Configuration Framework for GMPLS RSVP-TE", 2009,
              <draft-ietf-mpls-tp-framework>.

   [MPLS-TP-OAM-FWK]
              Busi, I. D. Allan, "Operations, Administration and B. Niven-Jenkins, "MPLS-TP OAM
              Maintenance Framework and
              Overview", 2009, for MPLS-based Transport Networks",
              2010, <draft-ietf-mpls-tp-oam-framework>.

   [RFC4447]  Martini, L., Rosen, E., El-Aawar, N., Smith, T., and G.
              Heron, "Pseudowire Setup and Maintenance Using the Label
              Distribution Protocol (LDP)", RFC 4447, April 2006.

Appendix A.  Additional Stuff

   This becomes an Appendix.

   [RFC5921]  Bocci, M., Bryant, S., Frost, D., Levrau, L., and L.
              Berger, "A Framework for MPLS in Transport Networks",
              RFC 5921, July 2010.

Authors' Addresses

   Elisa Bellagamba (editor)
   Ericsson
   Farogatan 6
   Kista,   164 40
   Sweden

   Phone: +46 761440785
   Email: elisa.bellagamba@ericsson.com

   Loa Andersson (editor)
   Ericsson
   Farogatan 6
   Kista,   164 40
   Sweden

   Phone:
   Email: loa.andersson@ericsson.com
   Pontus Skoldstrom (editor)
   Acreo AB
   Electrum 236
   Kista,   164 40
   Sweden

   Phone: +46 8 6327731
   Email: pontus.skoldstrom@acreo.se

   Dave Ward
   Juniper

   Phone:
   Email: dward@juniper.net

   John Drake
   Juniper

   Phone:
   Email: jdrake@juniper.net