[ofa-general] [PATCH] rds: use separate ports for TCP and IB

[Talpey, Thomas]

At 12:09 PM 5/30/2008, Roland Dreier wrote:
>
> > >> Not really much we can do about the general port space collision problem
> > >> unless and until the network stack guys are willing to cooperate though.
> > 
> > I don't think it has anything to do with the network stack code. 
>It's basically
> > an Internet license plate, issued by a separate authority.
>
>I just meant that currently, I can bind an iWARP listen and a normal TCP
>listen to the same port, and a connect attempt to one or the other will fail.

Oh THAT problem. :-)

Yes, at the moment TCP to the iWARP NIC is like talking to a different
host. But, RDMA-aware versions of a given protocol still need a second
port, unless there is explicit upper layer support for initiating the MPA
exchange. We have the same issue with NFSv3/RDMA, and we have
applied for a second port (the application is still pending within IANA). 

The second port is not needed for future NFSv4.1, which has RDMA
negotiation in its session establishment. And it's also not needed for
IB, which doesn't have an RDMA upgrade at all. But for simplicity, we'll
continue to use both.

Tom.