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RE: [802.3ae_Serial] Serial PMD call Tuesday






I believe the first question here will be are these actually 
rate adaptive deives or can you order them for the specific
signaling rate of choice?  

In a true SONET transponder, the PHY must be capable of line timed
operation.  This capability requires a very low jitter transfer system
with a positive jitter transfer bandwidth limit of 120 kHz (for OC192
systems).  To get this low bandwidth, many transponders integrate
a crystal filter (VCXO) in the loop.  While other parts of the
transponder are multi-rate, the VCXO is not.

Ed Grivna
Cypress Semiconductor

> Hi All,
> I have been following the discussions in this group only recently.
> 
> We see lot of  transponder vendors now offering variable data rate
> transponders which can support  SONET, 10GBE LAN and WAN rates. 
> My question is what are the issues(optical or Physical layer) that will
> come up when we try to interoperate a SONET 10G transponder with a pure
> 10GBE transponder.
> 
> I would appreciate if the group can respond to this clarification 
> 
> Thankx
> Rao Tatavarti. Ph.D
> Ceyba Inc.,
> 450 March Road, 
> Kanata, Ontario K2K 3K2
> Email: rao@xxxxxxxxx
> Tel: 613 599-5797 ext 5083
> Fax: 613 599-1247