[openib-general] IPoIB Question

[Michael Krause]

At 10:19 AM 10/23/2006, Michael S. Tsirkin wrote:
>Quoting r. Sean Hubbell <shubbell at dbresearch.net>:
> > I am looking at libsdp for the TCP funcationality and wanted to know if
> > libsdp supports UDP as well
>
>AFAIK, SDP can only emulate TCP sockets.

SDP is defined to work with AF_INET applications.  If using a shared 
library approach / pre-load, one can transparently enable any AF_INET 
application to utilize SDP without a recompile, etc.   The SDP Port Mapper 
specification for iWARP / service id for IB enable the connection 
management or whatever service it is implemented within to 
application-transparent discover the real target listen port and establish 
a SDP session nominally during connection establishment.    Implementations 
may vary in the robustness or policies used to determine what to off-load, 
number of off-load sessions, etc.  - in other words, a lot of opportunity 
and flexibility is provided to use SDP.

Note: WinSocks Direct on Windows provides an equivalent service though uses 
a proprietary protocol.  Vista will have SDP as defined in the specifications.

There are currently no plans to develop an equivalent for datagram 
applications.   Any datagram application (user or kernel) can already 
access the hardware directly and given RDMA is not defined for datagram, it 
was felt such a specification would provide minimal value.

Mike