[dat-discussions] RE: [openib-general] Re: [swg] Re: private data...

[Yaron Haviv]

> -----Original Message-----
> From: dat-discussions at yahoogroups.com [mailto:dat-
> discussions at yahoogroups.com] On Behalf Of Kanevsky, Arkady
> Sent: Thursday, October 20, 2005 5:07 PM
> To: dat-discussions at yahoogroups.com; Sean Hefty
> Cc: Lentini, James; swg at infinibandta.org; openib-general at openib.org
> Subject: RE: [dat-discussions] RE: [openib-general] Re: [swg] Re:
private
> data...
> 
> 
> Once this is defined ULP can decide on which Service ID(s) to listen.
> Requestor can send conn req to a specific Service ID (IB specific)
> or use higher level abstraction - TCP port.
> CM may be capable to translate TCP port to Service ID based on ULP.
> For example, iSER over IPoIB will be mapped to one Service ID and
> native iSER over IB will be mapped to another. But this is not simple.
> On another hand every intermediate level protocol (SDP, IPoIB) can
> do conversion. But this is also hard and is extension of existing
> protocol.

A small correction, there is no iSER over IPoIB, just iSER over Native
RDMA
There can be an iSCSI/TCP session running over IPoIB but than it's a
connectionless UD session (without ServiceID), also the iSER spec
defines that iSCSI/iSER is in precedence to iSCSI/TCP.

To add to the ongoing discussion, one of the major benefits in
maintaining the TCP port numbers for RDMA protocols is the ability to
leverage on existing naming services and configuration mechanisms.

e.g. NFS use Port mappers, other protocols use DHCP, DNS, SLP, iSNS,
well defined numbers, or other mechanisms, this way the upper layers
beyond the transport stay the same and don't bother if its IB or iWarp
or even if its plain TCP.   

If we don't preserve a simple/linear port mapping, we probably need to
reinvent name-services for RDMA as well.

Yaron