[c-nsp] 6500 GE modules comparison

[Eric Spaeth]

Kim Onnel wrote:
> Hi,
>
> Can i replace the WS-6748-GE-TX with WS-6548-GE-TX on a 6513 switch?
>   
Performance is lower, but that's a relative statement as the 6513 
architecture limits you to attachment to a single crossbar for slots 1-7.

> someone told me that the 65xx has less features to the 67xx, please
> help me identify what are those lacking features?
The 6548-GE-TX:

- Cannot do jumbo frames
- Has an 8G fabric attachment (vs 40G of the 6748, or 20G on your 1-7 
low speed slots)
- Has the same limitation of the 6148 in that every group of 8 ports is 
limited to 1gbit of output based on ASIC limitations
- Cannot be fitted with a distributed forwarding card
- Has a significantly lower buffer/port ratio.  The 6548 is 1MB per 8 
ports of buffer (ie, the ASIC has a 1MB buffer), whereas the 6748 is 
1.3MB per port.

This is definitely one of those cases where they cost less because you 
get less.

-Eric