[c-nsp] 1G (SFP) single-mode aggregation

Justin M. Streiner streiner at cluebyfour.org
Thu Dec 15 09:30:16 EST 2011

On Thu, 15 Dec 2011, Peter Rathlev wrote:

> So the question is: How many (1G) SFP switchports can one hope to
> terminate in a standard rack? And what is the smartest/cheapest/easiet
> way to do it?

How much space are you allocating for fiber termination bays and cable 

The one issue I've had with very high-density installations is that people 
often forget that someone needs to be able to make physical changes to the 
rack from time to time, and many peoples' fingers are not small enough to 
fumble around in an LC termination bay without potentially knocking 
something else offline (bump fade, so to speak).

The same issue exists with many switch vendors.  For example, with Cisco 
Cat6500s, the metal latches that are used to seat the cards in the chassis 
can interfere with access to the latches to uncouple LC jumpers from some 
of the SFP ports on a WS-X6748-SFP.

> ports. Power budget would seem to be around 8 kW per rack if the numbers
> from "show power" are used. (Anyone know what the real consumption is?)

The 6500s tend to pre-allocate power for each card when they are inserted 
or when the switch reboots, so the numbers you get from "show power" don't 
change much (if at all) as more SFPs are added to a linecard.


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