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

Versions: (draft-polk-ecrit-local-emergency-rph-namespace) 00 01 02 03 04

ECRIT Working Group                                          James Polk
Internet-Draft                                            Cisco Systems
Intended Status: Standards Track (as PS)                   Oct 27, 2008
Expires: April 27, 2009



            IANA Registering a SIP Resource Priority Header
              Namespace for Local Emergency Communications
           draft-ietf-ecrit-local-emergency-rph-namespace-00

Status of this Memo

   By submitting this Internet-Draft, each author represents that any
   applicable patent or other IPR claims of which he or she is aware
   have been or will be disclosed, and any of which he or she becomes
   aware will be disclosed, in accordance with Section 6 of 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 April 27, 2009.

Copyright Notice

   Copyright (C) The IETF Trust (2008).

Abstract

   This document creates and IANA registers the new Session Initiation
   Protocol (SIP) Resource Priority header (RPH) namespace "esnet" for
   local emergency usage to a public safety answering point (PSAP),
   between PSAPs, and between a PSAP and first responders and their
   organizations.







Polk                      Expires April 27, 2009               [Page 1]


Internet-Draft    SIP RPH Namespace for Local Emergencies      Oct 2008

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .  2
   2.  Rules of Usage of the Resource Priority Header  . . . . . . .  3
   3.  "esnet" Namespace Definition  . . . . . . . . . . . . . . . .  5
     3.1   Namespace Definition Rules and Guidelines . . . . . . . .  6
     3.2   The "esnet" Namespace . . . . . . . . . . . . . . . . . .  6
   4.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  7
     4.1   IANA Resource-Priority Namespace Registration . . . . . .  7
     4.2   IANA Priority-Value Registrations . . . . . . . . . . . .  7
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .  7
   6.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  7
   7.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  7
     7.1   Normative References  . . . . . . . . . . . . . . . . . .  7
     7.2   Informative References  . . . . . . . . . . . . . . . . .  8
       Author's Address  . . . . . . . . . . . . . . . . . . . . . .  8
       Intellectual Property and Copyright Statements  . . . . . . .  8


   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 [RFC2119].


1.  Introduction

   This document creates and IANA registers the new Session Initiation
   Protocol (SIP) Resource Priority header (RPH) namespace "esnet" for
   local emergency usage.  The SIP Resource-Priority header is defined
   in RFC 4412 [RFC4412]. This new namespace can be from a caller in
   distress, or added at the entry server into an emergency services
   managed network, towards a public safety answering point (PSAP),
   i.e., the 911 or 112-based emergency services call taker.  This
   new namespace can be used between PSAPs, and between a PSAP and
   first responders and their organizations.

   Within controlled environments, such as an IMS infrastructure or
   Emergency Services network (ESINet), where misuse can be reduced to
   a minimum where possible, providing an explicit priority indication
   facilitates treatment of emergency SIP messages according to local
   policy.  This indication is used to differentiate SIP signaling
   requests, or dialogs, from other requests or dialogs.

   Usage of the "esnet" namespace is to be defined in a future
   document(s). This document merely creates the namespace, per the
   rules within [RFC4412] necessitating a Standards Track RFC for
   IANA registering new RPH namespaces and their relative
   priority-value order.   [RFC4412] further states that modifying the
   order or the number of priority-values to a registered namespace
   SHOULD NOT occur, due to interoperability issues with dissimilar
   Implementations - perhaps separated by timing of each


Polk                      Expires April 27, 2009               [Page 2]


Internet-Draft    SIP RPH Namespace for Local Emergencies      Oct 2008

   implementation.

   From this fact about RFC 4412, and the possibility that within
   emergency services networks, a Multilevel Precedence and Preemption
   (MLPP)-like behavior can be achieved - ensuring more important calls
   are established or retained, the "esnet" namespace is given 5
   priority-levels.  MLPP-like SIP signaling is not defined in this
   document for 911/112/999 style emergency calling, but it is not
   prevented either.

   Within the ESINet, there will be emergency calls requiring different
   treatments, according to the type of call.  Does a citizen's call to
   a PSAP require the same, a higher or a lower relative priority than
   a PSAP's call to a police department, or the police chief?  What
   about either - relative to a call from within the ESINet to a
   federal government's department of national security, such as the US
   Department of Homeland Security?  For this reason, the "esnet"
   namespace is given multiple priority levels.

   This document does not define any of these behaviors, outside of
   reminding the rules of RFC 4412 apply - though examples of usage are
   included for completeness.  This document IANA registers the "esnet"
   RPH namespace for use within emergency services networks, not just
   of those from citizens to PSAPs.


2.  Rules of Usage of the Resource Priority Header

   This document updates the behaviors of the SIP Resource Priority
   header, defined in [RFC4412], during the treatment options
   surrounding this new "esnet" namespace only. The usage of the
   "esnet" namespace does not have a normal, or routine call level.
   Every use of this namespace will be in times of an emergency, where
   at least one end of the signaling is with a local emergency
   organization.

   The "esnet" namespace has 5 priority-values, in a specified relative
   priority order, and is a queue-based treatment namespace [RFC4412].
   Individual jurisdictions MAY configure their SIP entities for
   preemption treatment, but this is optional, and a local policy
   decision.

   Conceivably, this could be an example of a generic network diagram
   where the "esnet" namespace is used:










Polk                      Expires April 27, 2009               [Page 3]


Internet-Draft    SIP RPH Namespace for Local Emergencies      Oct 2008

                                                |<-"esnet" namespace->|
                                                |    *WILL* be used   |
     "esnet" namespace                          |        ,-------.
       can be used                              |      ,'         `.
     |<------------>|<---"esnet" namespace ---->|     /             \
  +----+            |       can be used      +-----+ |    ESINet     |
  | UA |---         |    --------------------|Proxy|-+    ------     |
  +----+   \        |   /                    +-----+ |               |
            \  ,-------+           ,-------.    |    |   +------+    |
  +----+     ,'         `.       ,'         `.  |    |   |PSAP-1|    |
  | UA |--- /  User       \     /   Service   \ |    |   +------+    |
  +----+   (    Network    +---+    Network    )|    |               |
            \             /     \             / |    |   +------+    |
  +----+    /`.         ,'       `.         .+-----+ |   |PSAP-2|    |
  | UA |----   '-------'           '-------' |Proxy|-+   +------+    |
  +----+            |                        +-----+ |               |
                    |                           |    |               |
  +----+            |                        +-----+ |   +------+    |
  | UA |---         |    --------------------|Proxy|-+   |PSAP-3|    |
  +----+   \        |   /                    +-----+ |   +------+    |
            \  ,-------+           ,-------.    |    |               |
  +----+     ,'         `.       ,'         `.  |    |               |
  | UA |--- /  User       \     /   Service   \ |    |   +------+    |
  +----+   (    Network    +---+    Network    )|    |   |PSAP-4|    |
            \             /     \             / |    |   +------+    |
  +----+    /`.         ,'       `.         .+-----+ |               |
  | UA |----   '-------'           '-------' |Proxy|-+  *ANY* can    |
  +----+            |                        +-----+ |  xfer a call  |
                    |                           |     \    | | |    /
                                                       `.  | | |  ,'
                                                         '-|-|-|-'
                                                           | | |
                                    Police  <--------------+ | |
                                             Fire <----------+ |
                                        Federal Agency <-------+

       Figure 1: Where 'esnet' Namespace Can or Will be used

   In Figure 1., UAs connect to service providers that can have SIP
   proxies.  When calling for emergency help, the UAs MAY include a
   "esnet" namespace in the SIP request.  Use of this new namespace is
   OPTIONAL, and likely is not trustworthy, unless SIP signaling is
   within a managed environment starting at the originating UAC.  This
   namespace, therefore, MAY be overwritten or deleted, contrary to the
   rules of RFC 4412 [RFC4412].  These proxies in the service provider
   MAY either

   o  accept the existing RPH value with "esnet" in it, if one is
      present, and grant relative preferential treatment to the request
      when forwarding it to the ESINet.

   o  replace any existing RPH value, if one is present, and insert an


Polk                      Expires April 27, 2009               [Page 4]


Internet-Draft    SIP RPH Namespace for Local Emergencies      Oct 2008

      "esnet" namespace and give relative preferential treatment to the
      request when forwarding it to the ESINet.

   o  insert an "esnet" namespace in a new RPH and give relative
      preferential treatment to the request when forwarding the SIP
      request towards the ESINet.

   Adjacent service providers can have a trust relationship in regards
   to emergency calling, and the receiving service provider can accept
   the inbound 'esnet' RPH namespace value and give preferential
   treatment to the request when forwarding it to the ESINet.

   On the other hand, SPs can choose to process each inbound SIP
   requests with its own policies, based on the type of request it is,
   in addition to the nature of the request.  If the request is
   destined for a PSAP, according to the receiving SP, it MAY treat the
   request as if it were coming directly from a UA, and act according
   to the 3 bullets above.

   Ultimately, the edge proxy at the ESINet will receive emergency SIP
   request, and process the request according to its rules.  Regardless
   of what RPH indications there are in the message, and what
   treatments the message has received, the ESINet edge proxy will
   ensure there is an RPH with the "esnet" namespace in the request.
   Local policy will dictate the priority-value to be assigned within
   the ESINet.  This document makes no recommendations.


3.  "esnet" Namespace Definition

   One thing to keep in mind for now is the fact that this namespace
   is not to be considered just "EMERGENCY" because there are a lot of
   different kinds of emergencies, some on a military scale ([RFC4412]
   defines 3 of these), some on a national scale ([RFC4412] defines 2
   of these), some on an international scale.  These types of
   emergencies can also have their own namespaces, and although there
   are 5 defined for other uses, more are possible - so the 911/112/999
   style of public user emergency calling for police or fire or
   ambulance (etc) does not have a monopoly on the word "emergency".

   Therefore the namespace "esnet" has been chosen, as it is most
   recognizable as that of citizen calling for help from a public
   authority type of organization.  This namespace will also be used
   for communications between emergency authorities, and MAY be used
   for emergency authorities calling public citizens.  An example of
   the later is a PSAP operator calling back someone who previously
   called 9111/112/999 and the communication was terminated before it
   should have been (in the operator's judgment).

   Here is an example of a Resource-Priority header using the esnet
   namespace:



Polk                      Expires April 27, 2009               [Page 5]


Internet-Draft    SIP RPH Namespace for Local Emergencies      Oct 2008

      Resource-Priority: esnet.0


3.1.  Namespace Definition Rules and Guidelines

   This specification defines one unique namespace for emergency
   calling scenarios, "esnet", constituting its registration with IANA.
   This IANA registration contains the facets defined in Section 9 of
   [RFC4412].

3.2.  The "esnet" Namespace

   Per the rules of [RFC4412], each namespace has a finite set of
   relative priority-value(s), listed (below) from lowest priority to
   highest priority.  In an attempt to not limit this namespace's use
   in the future, more than one priority-value is assigned to the
   "esnet" namespace.  This document does not RECOMMEND which
   priority-value is used where.  That is for another document to
   specify.  This document does RECOMMEND the choice within a national
   jurisdiction is coordinated by all sub-jurisdictions to maintain
   uniform SIP behavior throughout an emergency calling system.

   The relative priority order for the "esnet" namespace is as follows:

      (lowest)  esnet.0
                esnet.1
                esnet.2
                esnet.3
      (highest) esnet.4

   The "esnet" namespace will be assigned into the priority queuing
   algorithm (Section 4.5.2 of [RFC4412]) from the public user to the
   PSAP.  This does not limit its usage to only the priority queue
   algorithm; meaning the preemption algorithm can be used where the
   local jurisdiction preferred to preempt normal calls in lieu of
   completing emergency calls.  This document is not RECOMMENDING this
   usage, merely pointing out those behaviors is a matter of local
   policy.

   NOTE: at this time, there has not been sufficient discussion about
   whether or not preemption will be used for communications between
   PSAPs or between PSAPs and First responders (and their
   organizations).











Polk                      Expires April 27, 2009               [Page 6]


Internet-Draft    SIP RPH Namespace for Local Emergencies      Oct 2008

4.  IANA Considerations

4.1  IANA Resource-Priority Namespace Registration

   Within the "Resource-Priority Namespaces" of the sip-parameters
   section of IANA (created by [RFC4412]), the following entries will
   be added to this table:

                        Intended      New warn-   New resp.
   Namespace  Levels    Algorithm     code        code      Reference
   ---------  ------  --------------  ---------   --------- ---------
     esnet      5        queue           no          no     [This doc]


4.2  IANA Priority-Value Registrations

   Within the Resource-Priority Priority-values registry of the
   sip-parameters section of IANA, the following (below) is to be added
   to the table:

   Namespace: esnet
   Reference: (this document)
   Priority-Values (least to greatest): "0", "1","2", "3", "4"


5.  Security Considerations

   The Security considerations that apply to RFC 4412 [RFC4412] apply
   here.  This document introduces no new security issues relative to
   RFC 4412.

   That said, since this SIP header, used for emergency calling can
   have a great impact on local communications, providers SHOULD use
   caution when deciding if they want to use a preemption algorithm
   within the public space for 911/112/999 type calling.  As
   potentially already limited communications bandwidth might starve
   out all other types of calls in a location.  This decision might be
   desired; but this effect might not be desired.

6.  Acknowledgements

   Thanks to Ken Carlberg, Janet Gunn, Fred Baker and Keith Drage for
   help and encouragement with this effort.


7.  References

7.1  Normative References

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



Polk                      Expires April 27, 2009               [Page 7]


Internet-Draft    SIP RPH Namespace for Local Emergencies      Oct 2008

 [RFC4412] Schulzrinne, H., Polk, J., "Communications Resource
           Priority for the Session Initiation Protocol (SIP)", RFC
           4411, Feb 2006

7.2  Informative References

   none


Author's Address

   James Polk
   3913 Treemont Circle
   Colleyville, Texas  76034
   USA

   Phone: +1-817-271-3552
   Email: jmpolk@cisco.com



Full Copyright Statement

   Copyright (C) The IETF Trust (2008).

   This document is subject to the rights, licenses and restrictions
   contained in BCP 78, and except as set forth therein, the authors
   retain all their rights.

   This document and the information contained herein are provided on
   an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE
   REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE
   IETF TRUST AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL
   WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY
   WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE
   ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS
   FOR A PARTICULAR PURPOSE.


Intellectual Property

   The IETF takes no position regarding the validity or scope of any
   Intellectual Property Rights or other rights that might be claimed
   to pertain to the implementation or use of the technology described
   in this document or the extent to which any license under such
   rights might or might not be available; nor does it represent that
   it has made any independent effort to identify any such rights.
   Information on the procedures with respect to rights in RFC
   documents can be found in BCP 78 and BCP 79.

   Copies of IPR disclosures made to the IETF Secretariat and any
   assurances of licenses to be made available, or the result of an


Polk                      Expires April 27, 2009               [Page 8]


Internet-Draft    SIP RPH Namespace for Local Emergencies      Oct 2008

   attempt made to obtain a general license or permission for the use
   of such proprietary rights by implementers or users of this
   specification can be obtained from the IETF on-line IPR repository
   at http://www.ietf.org/ipr.

   The IETF invites any interested party to bring to its attention any
   copyrights, patents or patent applications, or other proprietary
   rights that may cover technology that may be required to implement
   this standard.  Please address the information to the IETF at
   ietf-ipr@ietf.org.


Acknowledgment

   Funding for the RFC Editor function is provided by the IETF
   Administrative Support Activity (IASA).






































Polk                      Expires April 27, 2009               [Page 9]


Html markup produced by rfcmarkup 1.129d, available from https://tools.ietf.org/tools/rfcmarkup/