On Tue, 7 Jun 2005, Michael Krause wrote: > At 09:28 AM 6/7/2005, Fab Tillier wrote: > > > From: Roland Dreier [mailto:[EMAIL PROTECTED] > > > Sent: Tuesday, June 07, 2005 8:38 AM > > > > > > Michael> Why not just use the IETF draft for RC / UC based IP over > > > Michael> IB and not worry about creating something new? > > > > > > I think we've come full circle. The original post was a suggestion on > > > how to handle the fact the the connected-mode IPoIB draft requires a > > > network stack to deal with different MTUs for different destinations > > > on the same logical link.
Yes, the ipoib wg opinion is that a node should be able to communicate in any IB mode. (I've had to implement such a setup for tokenring in the past - e.g. if the peer was on a ring with smaller MTU ). I beleive this is an issue that needs furhter discussion on the ipoverib discussion list in ietf. Would you restart the discussion there? We can update the draft as needed after a consensus is reached in the wg. > > > >That's right - by implementing IP segmentation in the IPoIB driver when going > >over UD, the driver could expose a single MTU to the network stack, thereby > >removing all the issues related to having per-endpoint MTUs. > > > >Keeping a 2K MTU for RC mode doesn't really take advantage of IB's RC > >capabilities. I'd probably target 64K as the MTU. > > The draft should state a minimum for all RC / UC which should be the TCP > MSS. Whether one does SAR over a UD endpoint independent of the underlying > physical MTU can be done but it should not require end-to-end understanding > of the operation, i.e. the send side tells its local that the TCP MSS is X > while the receive side only posts 2-4 KB buffers. This has been done over > Ethernet for years. > > Mike I suggest we move this discussion to ipoverib@ietf.org (can continue to cc this list) to involve all since there have been suggestions for draft update. Vivek __ Vivek Kashyap Linux Technology Center, IBM _______________________________________________ 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