[c-nsp] cat4k, module 4548, architecture, backplane performance

[Jochen Kaiser]

Hi,


I've a problem with cat4k architecture.
 
We are using a Cisco 4548 module.        
The board has 48 10/100/1000 Mbit ethernet ports. Each eight ports 
have a shared 1 Gigabit connection to the backplane. The total 
backplane bandwidth per module/blade is 6Gbit (12 Gbit FD).
The ports are combined in modulo 8 ranges:
... first gigabit connection serves ports 1 to 8 and so on.
   
How is the communication between ports:

a) 1 and 2?
b) 1 and 9?

Is there a switch logic on the board which grants short paths (without
using the backplane (except for some lookups)) or is this communication
in case a) and b) going over the backplane?
 
regards,
Jochen
-- 
Dipl. Inf. Jochen Kaiser, GPG 0x3C93A870, phone +49 9131 85-28681
Network Administration  mailto:jochen.kaiser at rrze.uni-erlangen.de
Regionales Rechenzentrum Universitaet Erlangen-Nuernberg, Germany
http://ipv6.rrze.uni-erlangen.de/~unrz111 private:jnkaiser at gmx.de