IP Telephony (iptel) -------------------- Charter Last Modified: 2007-10-15 Current Status: Active Working Group Chair(s): Jonathan Rosenberg Real-time Applications and Infrastructure Area Director(s): Jon Peterson Cullen Jennings Real-time Applications and Infrastructure Area Advisor: Cullen Jennings Mailing Lists: General Discussion:iptel@ietf.org To Subscribe: iptel-request@ietf.org In Body: put subscribe in subject Archive: http://www.ietf.org/mail-archive/web/iptel/index.html Description of Working Group: The focus of the IP Telephony (iptel) group is on the problems related to naming and routing for Voice over IP (VoIP) protocols. Naming is accomplished through the use of the tel URI, which specifies a URI for telephone numbers. The tel URI was originally defined in RFC 2806, which was developed outside of any IETF working group. The iptel working group is responsible for updating the specification based on extensive experience with the tel URI. It is chartered to develop any extensions to the tel URI, such as support for number portability indicators and trunk groups. Routing protocols for VoIP allow intermediaries, such as SIP proxies and H.323 gatekeepers, to make call routing decisions based on reachability information learned from peer elements. The iptel group has already defined a protocol, Telephony Routing over IP (TRIP), RFC 3219, which solves one aspect of this problem. Specifically, it handles the case where calls need to be routed between domains. It allows for the exchange of routing information between these providers, so that policies can be applied to the resulting data to create a forwarding information base. However, this protocol does not address all the scenarios of route information exchange between servers. One important scenario is the propagation of routing information between gateways and the signaling servers in front of them. This is also known as "gateway registration". It allows the signaling server to make a routing decision about which gateway to use based on dynamic information about the gateway resources. Vendors have deployed proprietary solutions for this communications interface. A standard is needed. The group will generate a standards track document that defines a protocol (possibly based on TRIP) for this interface. TRIP and the gateway registration protocol are orthogonal to the DNS-based mechanisms specified in ENUM and RFC 3264. Those mechanisms are used to translate a URI, representing a name, to an address. If that address is a phone number in the telephone network, trip and tgrep can be used to assist in determining the right route (through various gateways) to that number. The group will also generate a MIB document for TRIP. Note that the group is not working on elevating TRIP to Draft Standard at this time. Deliverables: 1. A proposed standard specification for gateway to server route exchange. 2. A proposed standard TRIP MIB specification, based heavily on the existing BGP-4 MIB documents. 3. A standards track update to the tel URI. 4. Standards track extensions to the tel URI for PSTN interoperability, such as number portability and trunk group identification. Goals and Milestones: Done Submit gateway location framework document to IESG for consideration as an RFC. Done Submit call processing syntax framework document to IESG for consideration as an RFC. Done Submit call processing syntax document to IESG for consideration as a Proposed Standard. Done Submit gateway location protocol document to IESG for consideration as an RFC. Done TRIP MIB Document submitted to IESG for consideration as proposed standard Done Tel URI revisions submitted to IESG Done Number portability extensions submitted to IESG for consideration as proposed standard Done Gateway to Server Route Exchange document submitted to IESG for consideration as proposed standard. Done Consider closing Internet-Drafts: No Current Internet-Drafts. Request For Comments: RFC Stat Published Title ------- -- ----------- ------------------------------------ RFC2824 I Jun 2000 Call Processing Language Framework and Requirements RFC2871 I Jul 2000 A Framework for a Gateway Location Protocol RFC3219 PS Jan 2002 Telephony Routing over IP (TRIP) RFC3872Standard Sep 2004 Management Information Base for Telephony Routing over IP (TRIP) RFC3880Standard Nov 2004 CPL: A Language for User Control of Internet Telephony Services RFC3966Standard Dec 2004 The tel URI for Telephone Numbers RFC4694 PS Oct 2006 Number Portability Parameters for the RFC4759 PS Dec 2006 The ENUM Dip Indicator Parameter for the RFC4904 PS Jun 2007 Representing trunk groups in tel/sip Uniform Resource Identifiers (URIs) RFC5140Standard Mar 2008 A Telephony Gateway REgistration Protocol (TGREP) RFC5341 PS Sep 2008 The Internet Assigned Number Authority (IANA) tel Uniform Resource Identifier (URI) Parameter Registry