[openib-general] Re: Dual Sided RMPP Support as well as OpenSMImplications

[Hal Rosenstock]

Hi Todd,

On Tue, 2006-04-11 at 13:15, Rimmer, Todd wrote:
> I haven't been watching this thread so I might be missing the point.
> 
> > -----Original Message-----
> > From: openib-general-bounces at openib.org
> > [mailto:openib-general-bounces at openib.org]On Behalf Of Hal Rosenstock
> > Sent: Tuesday, April 11, 2006 12:48 PM
> > 
> > On Tue, 2006-04-11 at 12:38, Sean Hefty wrote:
> > > Hal Rosenstock wrote:
> > > > I don't think that can work. If the request and response 
> > are RMPP'd, I
> > > > think a direction switch is needed so this can't be done.
> > > 
> > > A direction switch is only needed if we want to follow the 
> > DS RMPP protocol. 
> > > Why can't both sides just follow the sender-initiated 
> > protocol instead?  
> > 
> > In thinking about this a little, I see no reason this 
> > couldn't work. In
> > fact, that's one mode I have toyed with (a non conformant SA GetMulti*
> > mode) in developing SA MultiPathRecord.
> 
> It is a bad idea to implement a custom double sided approach.  This will 
> suddenly create various compliance and interop issues.  For example
> Windows Open Fabrics and Linux OpenSM might not interoperate.  Not to 
> mention other OSs (such as Solaris) which have their own IB stacks.

Understood. All I said was I used this as a development vehicle. It is
not intended to be checked into the tree.

> More interestingly, it is very likely that most uses of getmulti would 
> involve a requestor providing a request which would fit into a single 
> MAD packet and the RMPP protocol would not be fully needed by the 
> sender (eg. just the simple case of a single packet RMPP transfer 
> by sender with a multipacket RMPP response).  

Right.

> You will note up to 10 
> GIDs can fit in the request within a single packet.  The most common 
> uses will probably involve 2 source GIDs and 2 destination GIDs.

Yes.

> Hence perhaps the complexity of a compliant double sided solution 
> could even be avoided for now.

You lost me here. What do you have in mind ?

-- Hal

> Todd Rimmer