If you want to do Routing (ipv4 and ipv6)in hardware), the 4900M is a very good choice to go to 10G .
Also because of the Internal redundant Power supplies.
It has also much more CPU capacity and can run all 4k vlans with a spanning tree for each of them.
Also, full feature set ist less expensive than 3750G,
and cpu memory is sufficient to run routing-protocols with more than some dozend routes.
Cons:
- To use optical 1G SFP's in TwinGig Converters, you _must_ get the 2:1 oversubscribet half-module with the 8 X2 slots.
- just 512 M RAM for the CPU, boot messages indicate that just on DIMM has a module, but ther are'n any slots, its al solderd on-board
- 3750 fewer
- no netflow accounting -> also on 3750
- power consumption
For the HP-Way, i would recommend the 4800 (h3c/huawai) instead of the (really old) 5500 (3com) model,
or the 4210g-24 for access (fewer number of vlans than 4800); for 10G concentration, there is a high-sfp+-densityh3c 5800 model...
from http://h20195.www2.hp.com/v2/GetPDF.aspx/4AA1-4855ENN.pdf
that is the
HP A5820-24XG-SFP+ Switch (JC102A) for 24 10G SFP+ ports
-> a pair of them with , sa 4 10G bundled as interconnect and 1 or two links to each access-switch,
either
HP E4210-24G Switch (JF844A)
or the E 4800...
If you just want Layer2 with 100vlans and 6 switches with 4 10G ports suffit,
de E4210-48g will fit .
You may have problems getting a quote from hp for the former 3com/huawai/h3c products,
even when those swichtes are in their current marketing brocuhure July 2010 !
which in fact (esp the 4210) are cheaper than the 5500 (and a little bit newer)
and working very fine, i have a setup with 2 4800g-24sfp (interconnected with 10G cx4 "local connection module/cable!
to a bulk of 4200g-24 (optical sfp) , all prepared to get 10G upstream (insert xenpack) to
the 5820 when the bandwidth demand comes.
with the 5820, you can get internal second power supply, and less power consumption.
in Both Worlds, remember that for short connections (15 meters),
the "local connection Module" or CX4 Transcievers is much cheaper than optical module.
For SFP and SFP+, there are also Cables directly plugable into the sfp(+) slots to form the interconnect.
And last but not least, think of getting the optical modules from a third-party to reduce the project cost.
