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i need to trunk two 6509's together, both w/ sup720's.
My question is what is the advantage of using one (or both) of the
1000base-t ports on the sup720's vs using a 10/100/1000 port on a regular
48port blade for the trunk link. I ask be/c we have not yet acquired the
gbics for the sup720 1000base-T ports.

-TIA

In article <>,
John Smith <> wrote:
:i need to trunk two 6509's together, both w/ sup720's.
:My question is what is the advantage of using one (or both) of the
:1000base-t ports on the sup720's vs using a 10/100/1000 port on a regular
:48port blade for the trunk link.

The 48 port blade is oversubscribed -- the maximum throughput
possible from the blade to the backplane is:
- Classic interface: 32 Gbps shared bus
- Cef256: 8 Gbps per slot, 32 Gbps shared bus
- Cef720: dual 20 Gbps per slot (40 Gbps total)

http://www.cisco.com/en/US/products/...d8017376e.html

Thus if you run off the blade, then whether you can get full
throughput or not depends upon the kind of blade you have and depends
upon how you have populated and are utilizing the blade. Different
48 port blades have different ways of handling oversubscription;
for example, some of them have one 1 Gbps link for every 6 ports,
and cannot make use of "spare bandwidth" on the other port groups.
--
Are we *there* yet??

I would also look at blades from the perspective of buffer size for each
port. Also it is important to understand your application transaction flow
in a web commerce environment to figure out the amount of traffic that will
need to traverse between blades in the same chassis. The mix of classic
cards and non-classic cards in the same chassis should be considered so you
can consider the amount of packets that needs to traverse the local bus. If
you have Sup720B or better you can see the traffic utilization on the local
bus. Keep in mind if you use CSMs for load-balancing they are classic cards.
Distributing servers across ASICs is something to be considered if you don't
need all the ports per blade.




"Walter Roberson" <> wrote in message
news:d0ks25$jo3$...
> In article <>,
> John Smith <> wrote:
> :i need to trunk two 6509's together, both w/ sup720's.
> :My question is what is the advantage of using one (or both) of the
> :1000base-t ports on the sup720's vs using a 10/100/1000 port on a regular
> :48port blade for the trunk link.
>
> The 48 port blade is oversubscribed -- the maximum throughput
> possible from the blade to the backplane is:
> - Classic interface: 32 Gbps shared bus
> - Cef256: 8 Gbps per slot, 32 Gbps shared bus
> - Cef720: dual 20 Gbps per slot (40 Gbps total)
>
> http://www.cisco.com/en/US/products/...d8017376e.html
>
> Thus if you run off the blade, then whether you can get full
> throughput or not depends upon the kind of blade you have and depends
> upon how you have populated and are utilizing the blade. Different
> 48 port blades have different ways of handling oversubscription;
> for example, some of them have one 1 Gbps link for every 6 ports,
> and cannot make use of "spare bandwidth" on the other port groups.
> --
> Are we *there* yet??
>