> -----Original Message----- > From: [EMAIL PROTECTED] [mailto:openib-general- > [EMAIL PROTECTED] On Behalf Of James Lentini > Sent: Monday, August 29, 2005 3:35 PM > To: Guy German > Cc: openib-general@openib.org > Subject: Re: [openib-general] RDMA Generic Connection Management > > > What happens if multiple devices can reach the destination address? > How will they be enumerated to the consumer? >
Since its an IP based approach, it will work like traditional IP A preference is given to a device with the same subnet as destination In GbE if two NICs are on the same subnet then only one will be selected You can also use a LAG solution that will balance connections over multiple links, but it is done at the L2-3 layers (not exposed to the ULP) We should probably use the same approach and provide a single device handle to the ULP, we may have a virtual device handle representing few similar parallel devices (just like a LAG group has a virtual MAC), also maybe a good idea to pass an enum with some preference (e.g. single path or redundant or ...) Specifically in iSER the redundancy is handled in the upper layers The iSCSI discovery may return multiple src & dst IP addresses and the iSCSI multipath implementation will open multiple connections. There are many TCP/IP protocols that do that at the upper layers (e.g. GridFTP, ..), not sure how NFS does it. Also note that there was a new addendum to IB Multipath record query me & Hal proposed in IBTA that enable a client to ask "what are all the options to get from point A to point B ?", where A & B are identified by one of the GIDs we know about, and we can specify a flag for same port/hca/system preferences, this can be implemented under AT if we want. Yaron _______________________________________________ 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