[c-nsp] 4900M vs. 4503 for core

[Jason Gurtz]

We are doing a long overdue redesign of our network as part of a voip
implementation, hopefully ending up with a collapsed core w/routed access
layer.  A consultant has proposed the 4507 as access switches and a pair
of 3750-E switches as the core.  The 3750-E seems a strange choice to me
for a few reasons and I'm thinking a pair of 4900M or 4503 switches would
be a better fit looking forward.

We are a smaller shop (7 access switches including the datacenter) with
100Mb desktops and a mix of 100/1000 for servers.  Switch-to-switch trunks
are 1Gb.  The number of access switches is very unlikely to change and we
could, in the future move to a 10Gb.  The 4900M solution would save a
non-trivial amount over 4503 with Sup6.

Is there anything glaringly wrong with choosing the 4900M using twin-gig
based connections to the access layer over the 4503 Sup6 and 46xx line
cards in our situation?

~Jason