Re: Comments on draft-ietf-multi6-multihoming-requirements-00

[xxvaf <xxvaf@mfnx.net>]

> Now here's what's missing:
...
> 3.8 Impact on host stacks
> 
>   The solution must not destroy IPv6 connectivity for a legacy host 
>   implementing RFC 2373, RFC 2460, RFC 2553 and other basic IPv6 
>   specifications current in 4/2001. That is to say, if a host can work 
>   in a single-homed site, it must still be able to work in a 
>   multihomed site, even if it cannot benefit from multihoming.
> 
>   It would be compatible with this requirement for such a host to lose 
>   connectivity if the site's primary ISP connection failed.
> 
>   If the solution requires changes to the host stack, these changes
>   must be either minor, or in the form of logically separate functions
>   added to existing functions.
> 
>   If the solution requires changes to the socket API and/or the transport
>   layer, it must be possible to retain the original socket API and transport
>   protocols in parallel, even if they cannot benefit from multihoming.

IMHO, while it is desireable that a solution be backward-compatible with
with early-adopter ipv6 implementations, making this a hard requirement
will eliminate many potential solutions. It may well be the case that a
scalable multihoming architecture will require incompatible changes to TCP,
UDP, or the socket API, as some aspects of those protocols are not amenable
to multihoming. 

	--Vince