[swg] RE: [openib-general] socket based connectionmodel for IBproposal -round 4

[Yaron Haviv]

> -----Original Message-----
> From: openib-general-bounces at openib.org [mailto:openib-general-
> bounces at openib.org] On Behalf Of Sean Hefty
> Sent: Tuesday, November 29, 2005 6:30 PM
> To: Kanevsky, Arkady
> Cc: Ted H. Kim; swg at infinibandta.org; openib-general at openib.org
> Subject: Re: [swg] RE: [openib-general] socket based connectionmodel
for
> IBproposal -round 4
> 
> Kanevsky, Arkady wrote:
> > Sean,
> > SWG discussed today the extending private data format proposal to
> > SIDR_REQ.
> > The group does not see the need for it since ULP is no RDMA aware.
> > That is ULP does not use RDMA operations.
> > Do you have some specific ULP in mind for this functionality?
> > For UDP a different IP address can be used for each message. There
is no
> > persistent connection.
> 
> I didn't have any particular ULP in mind.  I was thinking more of a
> generic
> application that wanted to use UDP style addressing over IB, similar
to
> what's
> being discussed for using TCP style addressing over IB.
> 
> It seems that there needs to be a way to map a given destination
address
> to a
> remote QP/qkey.  Regardless if the IP address is carried in each ULP
> message, it
> would still need to be in the SIDR REQ in order to locate the correct
QP.
> 

Sean,

How about using ARP to get from IP to DGID+Partition
Followed by an SIDR to map DGID+PKey+Service to QKey & QP

It is the same concept as CMA that first uses IP stack (ARP etc') to get
to the remote end-point (in that case GID+PKey combination) followed by
SA-PR and CM REQ, we just substitute the CM REQ with a SIDR REQ
It may not solve all the cases but probably most of the practical ones 

Anyway the packets will need to carry some header (since it's not a
connected model), you can add more stuff in that header (e.g. can use
IPoIB header as is which contains already the src/dst IP) 

Yaron