On Dec 6, 2006, at 2:05 AM, Gleb Natapov wrote:
Actually I was wondering why there is a facility for having
multiple
LIDs for the same port. This led me to the entire series of
questions.
It is still not very clear to, as to what is the advantage of
assigning multiple LIDs to the same port. Does it give some
performance advantages?
Each LID has its own path through the fabric (ideally), this is the
way to
lower a congestion.
More specifically, multi-LID support is best for networks where there
are multiple paths between the same pair of peers (e.g., a fat tree
network with multiple core switches). If you don't have a multi-
route topology on your IB network, multi-LID support from the same
port is not likely to be useful.
To answer your specific question: multi-LID support from a single
port is not a bandwidth multiplier because you're still sending and
receiving from a single port on the host (which has a fixed bandwidth
capability).
--
Jeff Squyres
Server Virtualization Business Unit
Cisco Systems
