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

[Marian Ďurkovič]

On Wed, Mar 17, 2010 at 10:16:42AM +0000, Phil Mayers wrote:
> Hearing statements which add up to "this whole transceiver platform 
> depends on the transceiver, linecard hardware and firmware interacting 
> correctly" may read to some as "we plan on screwing you with expensive 
> official cisco transceivers".

Yet worse. This whole SFP+ ecosystem does not work right even with official
transceivers due to various pitfalls.

Apparently, Nexus 7000 linecards use older, less-flexible host-side
chipset which doesn't have adaptive EDC - thus current twinax (CX1)
cables don't work.

On Nexus 5000, Cisco made an effort to support other vendor's CX1s since
the chipset allows it, but this still means the system doesn't work in
general, but only with a few tested combinations where the EDC parameters
are known. 

This is definitely not what anyone could call general-purpose, interoperable,
standards-based and reliable network. 
   
And let's face it - the lower costs of CX1 are no way coupled to SFP+ form
factor. XFP has serial host interface as well so attaching twinax cables
is straightforward. Better yet, EDC resides in the XFP module, so XFP-CX1
will work in any XFP slot available today.

Bottom line: SFP+ form factor aimed at lower costs to speed up 10G adoption.
But the reality looks much different - limited options, sparse CX1 support,
interop issues, more vendor locks. All of those drive costs *up*.