[c-nsp] DS3 Y-Cable

[Dave Temkin]

Agreed.  On the IGX, of the entire equation, the Y cables were the lowest
common denominator/most likely to fail item.  Kind of ironic, eh?


On Fri, 17 Mar 2006, Mark Rogaski wrote:

> An entity claiming to be Eric Pylko (eric at infinitenetworks.us) wrote:
> :
> : I don't know enough about the Y-adapter or the SMB cables it talks
> : about. I don't know if there is something in the MGX hardware that
> : "watches" the primary MGX for a failure state. That would be my guess.
> :
>
> The Y-cabling on the MGX is not between individual MGX chassis, but between
> corresponding ports on redundant service modules or trunk cards.  This is
> also used on the IGX and BPX platforms.  The PXM processor card in the MGX
> does indeed do the watching.  If a failure occurs on one of the service
> modules, the failed card is reset and the standby card turns on its
> transmitters and takes over.  In most cases it works pretty well, the
> connected devices may only see a small number of path errors and a few
> dropped packets.
>
> However, I've swapped enough y-cables to know that manufacturing quality
> is a big issue for this particular arrangement.
>
> Mark
>
>