[openib-general] Re: [swg] Re: private data...

[Fab Tillier]

> From: Roland Dreier [mailto:rolandd at cisco.com]
> Sent: Thursday, October 20, 2005 1:18 PM
> 
>     Fab> My understanding was that we want the IBTA to add a section
>     Fab> in the IB spec to define this higher-level connection
>     Fab> management protocol, specifically the use of the first
>     Fab> 32-bytes of the private data in the REQ to contain the source
>     Fab> and destination IP addresses associated with the source and
>     Fab> destination GIDs in the primary and alternate paths.
> 
> Yes, but there's no point in doing this unless there's a defined range
> of service IDs to map TCP ports onto.  If every protocol needs to
> define its own service ID mapping, then the protocol might as well
> define how it uses the IB CM private data to carry IP addressing info.
> This is exactly what SDP does today.  However, this solution is
> apparently not acceptable for NFS/RDMA.  Hence the current discussion.

I'm not saying we shouldn't define a range of service IDs, I'm questioning
whether we should restrict the use of this protocol to just the defined range of
service IDs.  I think there's a benefit in having different protocols use a
well-established and defined way of mapping IP addresses to IB.

I'd like to see us define the protocol independent of the service ID.  We can
then establish a service ID range to be used with this protocol for NFS/RDMA, or
for more generic TCP mappings, but these are two different issues to me.

- Fab