[ofa-general] peer to peer connections support

[Sean Hefty]

>     My thinking was that the peer to peer model would have both sides call
>     connect only.  The peer to peer connection model only kicks in when both
>     sides are in the REQ sent state.
> 
> 
> Is this observation based on the wording used by the spec? if yes, can 
> you point on the sentence/s that does it?

I was basing this on the active side state diagram.

>From my reading, I could not conclude that implementing it in a way 
> that both sides do listen and later set the peer to peer bit on the REQ 
> such that --if-- there's a "matching" REQ for the incoming REQ one side 
> sends REP and the other side ignores the incoming REQ etc - is against 
> the spec.

This leaves a window where a REQ can be received the call to listen, and 
the call to connect.

> I understand that under TCP there's also a notion of peer to peer and 
> client/server connections, I'll give it a look next week to see what's 
> the foundations over there.

That would be good.  I think the difference is that with TCP the 
listener and connector would be distinguished by their local ports, so 
its clear how to direct an incoming request.  IB doesn't assign a SID to 
a connector.  I'm not sure how TCP handles the race condition.

- Sean