Re: [Softwires] MTU problem in DS-lite

[Zhen Cao <caozhenpku at gmail.com>]

Got it. Thanks, Alain.

Best Regards,
Zhen

On Mon, Aug 17, 2009 at 8:43 PM, Durand,
Alain<Alain_Durand at cable.comcast.com> wrote:
>
>
>
> On 8/16/09 3:56 AM, "Zhen Cao" <caozhenpku at gmail.com> wrote:
>
> Hi Alain and All,
>
> I have a question on MTU issue in ipv4-in-ipv6 softwire. I notice
> Sec.10.2 of DS-Lite draft has discussed the MTU problem. The draft
> introduces one possible way of using TCP MSS option to avoid IP layer
> fragmentation and reassembly. It is a good idea but how about the case
> for UDP sockets? I suppose there should be a general way to handle the
> MTU issue? Thanks for any explanation.
>
>
> Zhen,
>
> The ‘generic’ way is as described in the draft & RFC2473, ie encapsulate the
> IPv4 datagram into an IPv6 datagram that happens to be too big to be
> transmitted and the fragment the IPv6 datagram. Reverse the procedure at the
> end of the tunnel.
>
>    - Alain.