Softwire BOF (softwire)

xxxxxxxx, November x at xxxx-xxxx
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CHAIR: Alain Durand <Alain_Durand@cable.comcast.com>

DESCRIPTION: 

The Softwires Working Group is specifying the standardization of 
discovery, control and encapsulation methods for connecting IPv4 
networks across IPv6 networks, IPv6networks across IPv4 networks 
in a way that will encourage multiple, inter-operable vendor 
implementations. For various reasons (financial or political), 
native IPv4 and/or IPv6 transport may not be available in all 
cases, and there is need to tunnel IPv4 in IPv6 or IPv6 in IPv4 
to cross a part of the network which is not IPv4 or IPv6 capable. 
Configured tunnels or softwires are suited for the inter-networking 
job. Non-interoperable tunneling mechanisms have been developed 
based on the RFC3053 tunnel broker concept, and in addition, 
standardized mechanisms like RFC2893, RFC2473, GRE, L2TP, etc. have 
been used in some scenarios. Other deployments use non-standardized, 
incomplete solutions. The lack of interoperable and/or standardized 
solution in that space has been noted in the v6ops WG scenario 
analysis.

The focus of this WG is to define a softwire setup negotiation 
protocol and encapsulation to be use between a node and the 
corresponding softwire end-point. Softwire configuration includes 
two phases: softwire end point discovery and softwire set-up. A 
primary goal is to reuse and extend (if necessary) existing 
technologies.

In the softwire set-up phase, the initator and the ISP negotiate 
the parameters necessary to establish the softwire. Those include:

- The encapsulation type: IPv4-over-IPv6 or IPv6-over-IPv4 with 
  a possible intermediary layer (e.g. UDP). This encapsulation 
  negotiation should be extensible to cover future methods of 
  both unicast and multicast traffic.

- How to obtain the IP addresses to use for the softwire end-points. 
  This could be done with an out-of-band mechanism or directly 
  negotiated at set-up phase.

In the softwire end point discovery phase, the initiator gets a name 
or an IP address for the ISP-side end point of the softwire to 
establish. This phase is orthogonal to the set-up one.

The initial milestone for this working group will be the set-up phase. 
This WG is not chartered to work on the discovery phase and a re-charter 
will be needed prior to undertaking such work; once the base work has 
been completed (or is well under way), WG may consider re-chartering to 
address discovery.

The WG will reuse existing technologies as much as possible and will 
create additional building blocks when necessary


AGENDA:

- problem statement
- initial review of potential solutions