Signaling Transport (sigtran)

Last Modified: 2008-07-31

Additional information is available at tools.ietf.org/wg/sigtran

Chair(s):

Real-time Applications and Infrastructure Area Director(s):

Real-time Applications and Infrastructure Area Advisor:

Technical Advisor(s):

Mailing Lists:

General Discussion: sigtran@ietf.org
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Archive: http://www.ietf.org/mail-archive/web/sigtran/index.html

Description of Working Group:

The primary purpose of this working group will be to address the
transport of packet-based PSTN signaling over IP Networks, taking into
account functional and performance requirements of the PSTN signaling.

For interworking with PSTN, IP networks will need to transport
signaling
such as Q.931 or SS7 ISUP messages between IP nodes such as a
Signaling
Gateway and Media Gateway Controller or Media Gateway.

Examples of such transport include:

  - transport of signaling between a Signaling Gateway and Media
Gateway
    or Media Gateway Controller
  - transport of signaling ("backhaul") from a Media Gateway to a Media
    Gateway Controller
  - transport of TCAP between a Signaling Gateway and other IP nodes

Applications include:

  - Internet dial-up remote access
  - IP telephony interworking with PSTN
  - Other services as identified


Specific goals are:

1. Architecture and Performance Requirements: The working group will
  produce an informational RFC identifying functionality and
  performance requirements to support signaling over IP. Signaling
  messages have very stringent loss and delay requirements in the
  existing telephone networks that need to be supported.

2- Transport: The working group will produce a standards track
  proposal or proposals defining transport of signaling protocols
  using SCTP, based on the requirements identified above.


These proposals will identify the method of encapsulation of different
signaling protocols.  This will include differentiating between
different protocols being carried, and what components are
transported,
translated or terminated at the SG.  Security and resilience must be
addressed.

Note: TCAP is a transaction protocol with different functions and
      requirements than call control signaling.  This will need to be
      taken into account in its mapping to IP networks.

      This work will be done in conjunction with other IETF working
      groups looking at similar issues.  The working group will also
      ensure that good information conduits exist with groups in other
      standards groups with expertise in the relevant signaling
      protocols or in the network requirements for the transport of
the
      relevant signaling protocols.

The group will make use of existing IETF QoS and security technology
and
will not address creation of new QoS or security functions for IP
networks. Nor will the working group work on defining new call control
or device control protocols.

Goals and Milestones:

Done    Submit Initial draft of Signaling Architecture and Performance Requirements document as an Internet-Draft
Done    Issue initial IDs on Transport Layer Protocols and Encapsulation of Signaling Protocols
Done    Submit requirements document to IESG for publication as an RFC
Done    Submit revised version of drafts incorporating discussions and early implementation experience.
Done    Submit IP-based transport protocol draft to IESG for publication as a Standards-track RFC
Done    Submit initial adaptation drafts to IESG for consideration as a Proposed Standard
Done    Submit protocol Applicability Statements draft to IESG for consideration as an Informationl RFC
Done    Submit protocol MIB draft to IESG for consideration as an Proposed Standard
Done    Submit security framework to IESG for consideration as Proposed Standard
Done    Resubmit updated IUA specification to IESG for consideration as proposed standard
Done    Submit remaining adaptation drafts to IESG for consideration as a Proposed Standard
Done    Submit implementation guidelines and other extensions based on testing to IESG for consideration as Proposed Standard

No Current Internet-Drafts

Request For Comments:

Architectural Framework for Signaling Transport (RFC 2719) (48646 bytes)
Stream Control Transmission Protocol (RFC 2960) (297757 bytes) obsoleted by RFC 4960/ updated by RFC 3309
ISDN Q.921-User Adaptation Layer (RFC 3057) (140327 bytes) obsoleted by RFC 4233/ updated by RFC 3807
Stream Control Transmission Protocol Applicability Statement (RFC 3257) (24198 bytes)
Signaling System 7 (SS7) Message Transfer Part (MTP)2 - User Adaption Layer (RFC 3331) (210807 bytes)
SS7 MTP3-User Adaptation Layer (M3UA) (RFC 3332) (265055 bytes) obsoleted by RFC 4666
Security Considerations for SIGTRAN Protocols (RFC 3788) (27125 bytes)
V5.2-User Adaption Layer (V5UA) (RFC 3807) (49748 bytes) updates RFC 3057
Stream Control Transmission Protocol Management Information Base (RFC 3873) (82403 bytes)
Signalling Connection Control Part User Adaptation Layer (SUA) (RFC 3868) (294116 bytes)
Signaling System 7 (SS7) Message Transfer Part 2 (MTP2) - User Peer-to-Peer Adaptation Layer (M2PA) (RFC 4165) (114669 bytes)
Digital Private Network Signaling System (DPNSS)/Digital Access Signaling System 2 (DASS 2) Extensions to the IUA protocol (RFC 4129) (29034 bytes)
Integrated Services Digital Network (ISDN) Q.921-User Adaptation Layer (RFC 4233) (157857 bytes) obsoletes RFC 3057/ obsoleted by RFC 5133
Telephony Signalling Transport over Stream Control Transmission Protocol (SCTP) Applicability (RFC 4166) (46659 bytes)
Signaling System 7 (SS7) Message Transfer Part 3 (MTP3) - User Adaptation Layer (M3UA) (RFC 4666) (292991 bytes) obsoletes RFC 3332
Terminal Endpoint Identifier (TEI) Query Request Number Change (RFC 5133) (7279 bytes) obsoletes RFC 4233