[openib-general] RMPP Requirements

[Hal Rosenstock]

Sean Hefty wrote:
> * The access layer needs to know if the RMPP header is in a MAD or
> not.  I think that this can be determined by the management class.

Not sure what you mean by "determined by the management class".
I think it is at a minimum class and method (at least for SA today).

> * It needs to know the offset of the RMPP header into the MAD.  This
> seems fixed for currently defined classes.

It is fixed for all classes using RMPP. Not sure what you mean by currently
defined classes.

> * The access layer needs to know what version of RMPP is being used.
> This is given in the RMPP header, which would work, provided that the
> header doesn't change.

I don't think the position of the version in the header can change without
the
base version changing. That's not likely any time soon :-)

> Given this, the access layer should be able to determine if RMPP is
> active.

Sure the RMPPFlags,Active can be checked. On the responder side,
do we want to make sure that RMPP is allowed/supported on that class/method
and possibly attribute ?

> I don't think it matters which of the three types of transfers are in use.

I'm not quite with you yet on this. I can see it for sender and receiver but
doesn't someone have to indicate a 2 sided transfer ? Where/how do you see
that being handled ?

I think timeouts need some exposure through the API somehow. In order to
handle the transaction timeout properly, it appears that the packet lifetime
in both directions needs to be obtained (passed in ?). It also appears that
in order to set the response time properly access to the
ClassPortInfo:RespTimeValue is needed (which may change) if present.

-- Hal