On Friday 30 May 2008 18:29:01 Talpey, Thomas wrote: > Yes, at the moment TCP to the iWARP NIC is like talking to a different > host. But, RDMA-aware versions of a given protocol still need a second > port, unless there is explicit upper layer support for initiating the MPA > exchange. We have the same issue with NFSv3/RDMA, and we have > applied for a second port (the application is still pending within IANA).
This may also become a problem for RDS, but in a different sense. If you bind an RDS socket to a specific IP address, this also selects a transport. If you bind to an IP address owned by ib0, you select the IB transport. If you bind to an IP address owned by say eth0, you select the TCP transport. Now if the one and only NIC in the system is an iWARP NIC, which transport should we select? Both iWARP and TCP can be legitimate choices, depending on the hosts we're talking to (and how do we find out whether the remote node supports iWARP or not?) I think for now it's okay to default to iWARP and punt if the remote doesn't support it. But in the long run this is something that needs to be addressed - either in RDS, or in the way ofed handles iWARP NICs. In fact it may not be such a bad idea to treat an iWARP NIC as two devices, and register one ethX device (owned exclusively by the normal stack) and one ibX device (owned mostly by the ofed stack, maybe with the exception of ARP and such). Would that work with protocols like NFS/RDMA neogtiation - ie can you negotiate specify a secondary port _and_ address? Olaf -- Olaf Kirch | --- o --- Nous sommes du soleil we love when we play [EMAIL PROTECTED] | / | \ sol.dhoop.naytheet.ah kin.ir.samse.qurax _______________________________________________ general mailing list general@lists.openfabrics.org http://lists.openfabrics.org/cgi-bin/mailman/listinfo/general To unsubscribe, please visit http://openib.org/mailman/listinfo/openib-general
