[c-nsp] DWDM optics on 6500s

[Richard A Steenbergen]

On Mon, Oct 05, 2009 at 04:06:31PM +0100, Nick Hilliard wrote:
> Depends on what you do with them.  They are a first generation blade, and 
> are 6yo technology at this stage and, well, things have moved on since 
> 2003.  XENPAK is moribund as a transceiver type which means that any money 
> you invest into buying transceivers will probably be written off when you 
> retire the blade.

Don't forget they are absurdly under-buffered (16MB per card, compared
to 256MB for 6708), and you can easily cause head of line blocking with
certain traffic profiles. If you want to run anywhere close to line rate
on them you need to monitor for drops or overruns and be prepared to
play the port shuffle game to find an arrangement that works. Passing a
lot of traffic within the same fabric channel (from port 1<->2, or
3<->4) is the biggest sin, it will start dropping at 7 Gbps.

-- 
Richard A Steenbergen <ras at e-gerbil.net>       http://www.e-gerbil.net/ras
GPG Key ID: 0xF8B12CBC (7535 7F59 8204 ED1F CC1C 53AF 4C41 5ECA F8B1 2CBC)