On 11/4/05, Bob Woodruff <[EMAIL PROTECTED]> wrote: > Woody wrote, > >Perhaps if tunneling udp packets over RC connections rather than > >UD connections provides better performance, as was seen in the RDS > >experiment, then why not just convert > >IPoIB to use a connected model (rather than datagrams) > >and then all existing IP upper level > >protocols would could benefit, TCP, UDP, SCTP, .... > > Saying this another way. > Make the hardware run the existing protocols better, don't > design a new protocol to work around the problems with a > specific hardware transport. >
What about SDP? Isn't SDP bypassing the existing TCP protocol stack to take advantage of a specific harware transport - IB? RDS is somewhat like SDP in that it offloads/accelerates SOCK_DGRAM instead of SOCK_STREAM. > woody > > > > > -----Original Message----- > From: Caitlin Bestler [mailto:[EMAIL PROTECTED] > Sent: Friday, November 04, 2005 2:31 PM > To: Woodruff, Robert J; Rick Frank; Ranjit Pandit; Grant Grundler > Cc: openib-general@openib.org > Subject: RE: [openib-general] [ANNOUNCE] Contribute RDS ( > ReliableDatagramSockets) to OpenIB > > > > > -----Original Message----- > > From: [EMAIL PROTECTED] > > [mailto:[EMAIL PROTECTED] On Behalf Of Bob Woodruff > > Sent: Friday, November 04, 2005 2:15 PM > > To: 'Rick Frank'; Ranjit Pandit; Grant Grundler > > Cc: openib-general@openib.org > > Subject: RE: [openib-general] [ANNOUNCE] Contribute RDS ( > > ReliableDatagramSockets) to OpenIB > > > > Rick wrote, > > >I've atttached a draft proposal for RDS from Oracle which discusses > > >some of > > > > >the motivation for RDS. > > > > Couple of questions/comments on the spec. > > > > > > AF_INET_OFFLOAD should be renamed to something like AF_INET_RDS. > > > > Would something like SCTP provide the same type of > > capabilities (relaible datagrams) that you are suggesting to > > add with RDP ? > > > > Each stream within an SCTP association provides a reliable, > ordered service. > > There would be two primary constraints in using SCTP for > this usage profile: > > 1) The Stream ID is 16 bits, and the natural mapping would > be to have each stream represent a source/destination > pairing. That would imply fewer than 256 endpoints per > host. If the source were encoded by hand then the limitation > would be 64K, but that's an awkard mix of application and > transport layer encoding. > 2) The network has to be composed of SCTP friendly equipment. > When IP network equipment operated exclusively at L2/L3, > and L4 was left to the endpoints, SCTP would have had no > problem being deployed. But because of security and IPV4 > address shortages there are a lot of middleboxes that are > L4 aware, and generally that L4 awareness is limited to > TCP and UDP. > > SCTP support would also have to be part of the offload device. > RDS enables reliable datagrams using existing offloaded RC > services (IB RC, iWARP, TOE). No NIC enhancements are required. > > > > > _______________________________________________ > openib-general mailing list > openib-general@openib.org > http://openib.org/mailman/listinfo/openib-general > > To unsubscribe, please visit > http://openib.org/mailman/listinfo/openib-general > > _______________________________________________ > openib-general mailing list > openib-general@openib.org > http://openib.org/mailman/listinfo/openib-general > > To unsubscribe, please visit http://openib.org/mailman/listinfo/openib-general > _______________________________________________ openib-general mailing list openib-general@openib.org http://openib.org/mailman/listinfo/openib-general To unsubscribe, please visit http://openib.org/mailman/listinfo/openib-general