Softwires (softwire) -------------------- Charter Last Modified: 2009-04-13 Current Status: Active Working Group Chair(s): Alain Durand David Ward Internet Area Director(s): Ralph Droms Jari Arkko Internet Area Advisor: Ralph Droms Technical Advisor(s): Xing Li Mailing Lists: General Discussion:softwires@ietf.org To Subscribe: softwires-request@ietf.org In Body: With a subject line: subscribe Archive: http://www.ietf.org/mail-archive/web/softwires/current/maillist.html Description of Working Group: The Softwires Working Group is specifying the standardization of discovery, control and encapsulation methods for connecting IPv4 networks across IPv6 networks and IPv6 networks across IPv4 networks in a way that will encourage multiple, inter-operable implementations. For various reasons, native IPv4 and/or IPv6 transport may not be available in all cases, and there is a need to tunnel IPv4 in IPv6 or IPv6 in IPv4 to cross a part of the network which is not IPv4 or IPv6 capable. The Softwire Problem Statement, RFC 4925, identifies two distinct topological scenarios that the WG will provide solutions for, "Hubs and Spokes" and "Mesh." In the former case, hosts or "stub" networks are attached via individual, point-to-point, IPv4 over IPv6 or IPv6 over IPv4 softwires to a centralized Softwire Concentrator. In the latter case (Mesh), network islands of one Address Family (IPv4 or IPv6) are connected over a network of another Address Family via point to multi-point softwires among Address family Border Routers (AFBRs). The focus of this WG is to: Document the softwire encapsulation and control protocol usage for one Address Family (IPv6 or IPv4) over another within the defined problem spaces set out in RFC 4925. Define "Dual-Stack Lite" which uses softwires and IPv4 NAT functions to reduce the amount of Global and RFC 1918 Local IPv4 addressing necessary for a Service Provider with an IPv6-enabled network to continue delivering IPv4 reachability to its customers. The WG will reuse existing technologies as much as possible and only when necessary, create additional protocol building blocks. For generality, all base SOFTWIRE encapsulation mechanisms should support all combinations of IP versions over one other (IPv4 over IPv6, IPv6 over IPv4, IPv4 over IPv4, IPv6 over IPv6). IPv4 to IPv6 translation mechanisms (NAT-PT), new addressing schemes, and block address assignments are out of scope. DHCP options developed in this group will be reviewed jointly with the DHC WG. BGP and other routing and signaling protocols developed in this group will be reviewed jointly with the proper working groups and other workings that may take interest (e.g. IDR, L3VPN, PIM, LDP, SAAG, etc). Goals and Milestones: Done Submit a problem statement to the IESG to be considered as an Informational RFC Nov 2008 Submit Mesh softwire encapsulation and control protocol to the IESG to be considered as a Proposed Standard Nov 2008 Submit H&S softwire encapsulation and control protocol to the IESG to be considered as a Proposed Standard Mar 2009 Submit dual-stack lite to the IESG to be considered as a Proposed Standard. The initial basis for this solution is described in draft-durand-dual-stack-lite-00.txt and draft-droms-softwires-snat-01.txt. Dec 2009 Submit softwires MIB to the IESG to be considered as Proposed Standard Internet-Drafts: Posted Revised I-D Title ------ ------- -------------------------------------------- Jun 2006 Apr 2009 Softwire Hub & Spoke Deployment Framework with L2TPv2 Jun 2006 May 2009 Softwire Security Analysis and Requirements Apr 2007 Feb 2009 Softwire Mesh Framework Mar 2008 Apr 2009 BGP IPsec Tunnel Encapsulation Attribute Dec 2008 May 2009 Load Balancing for Mesh Softwires Mar 2009 Mar 2009 Dual-stack lite broadband deployments post IPv4 exhaustion Request For Comments: RFC Stat Published Title ------- -- ----------- ------------------------------------ RFC4925 I Jul 2007 Softwire Problem Statement RFC5512 PS Apr 2009 The BGP Encapsulation Subsequent Address Family Identifier (SAFI) and the BGP Tunnel Encapsulation Attribute RFC5549 PS May 2009 Advertising IPv4 Network Layer Reachability Information with an IPv6 Next Hop RFC5543 PS May 2009 BGP Traffic Engineering Attribute