Re: TCP limitations (was Re: ISCSI: Urgent Flag requirement violates TCP.)

["Bernard D. Aboba" <aboba@internaut.com>]

> Bernard:
> 
> Question for you.. I remember reading over Costa's RDMA 
> proposal and it seems to me that he proposes using TCP options.
> How does this interact with the use of SACK TCP? I know the
> WG has discussed the need for SACK (or possibly not) and I
> am just curious... will the use of a RDMA option limit you from
> using SACK?
> 

This is a very good question. In theory, there should be no reason
not to be able to do both. However, I'm also told that dealing with
all the option possibilities in silicon may be difficult at 10+ Gbps.
So in practice, designers may choose to focus on certain "likely"
option sets for the fast path.