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. _______________________________________________ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
