[c-nsp] Cheap 10G between 7600 and Procurve 5406zl

[Lincoln Dale]

On 18/03/2010, at 7:10 PM, Marian Ďurkovič wrote:
>>> In addition, by buying kit which takes X2 modules, you're committing a
>>> huge amount of transceiver capex on a particular vendor (i.e. Cisco or
>>> HP) which cannot then be moved to another vendor, because no-one else in
>>> the industry uses them.  This is strong vendor lock-on.
> 
> I'll add a few points here:
> 
> 1) (multirate) XFP is universal module - it can be used in LAN switches for both
> LAN PHY and WAN PHY, in routers for both ethernet and POS interfaces, in
> SONET/SDH equipment, in DWDM equipment, in various L1 converters/repeaters, etc.

no disagreement.  SFP+ is not intended for "telecom" use cases.  its why Clock Data Rate recovery is not part of SFF-8431.

again - choice point for X2 _originally_ was because XFP did not exist at that point in time.

> 
> 2) XFPs don't contain XAUI->serial muxes/demuxes inside, thus need less power
> and have lower latency.

this is a moot point if the ASIC in question is already operating in XAUI, which is often the case if same port handles 1GbE ports.


> 3) XFPs have less electronics inside and are produced in larger quantities so
> their price is much lower - it might well be around 1/2 of the X2 price.

not sure if you are comparing to X2 or SFP+ but as has been pointed out SFP+ has less electronics in it than XFP.
in many uses (particularly datacenter where its targeted), power consumption & latency are lower than XFP particularly in the CX1 case.

again, i'd say there is no one "sing;e perfect transceiver".  different markets, different places in the network, different requirements.


cheers,

lincoln.