Cisco Catalyst 6500 switch capacity questions

We have a customer that requires redundant 10-GE uplinks from a Cisco Catalyst 6500-series switch to 15 closets.  The customer is hoping to implement a 6513.  I realize that the 10-GE line cards are oversubscribed on this platform (2:1 for the 8-port, and 4:1 on the 16-port modules), but I have several "deeper dive" questions.

We've received information indicating that the 6509 is better suited to handle this level of 10-GE density than , and I'm wondering why.  Here's a link indicating that the 6513 can only handle 20 10-GE (XENPAK) ports, and that the 6509 can handle 32.

These switches handle non-XENPAK line cards, however, including 8-port and 16-port boards w/ X2 modules.  I realize these are oversubscribed at 2:1 and 4:1, respectively, but the Cisco Product dictates that you can achieve a total of 84 such ports in the 6513 chassis (compared to 130 for the 6509).

So, my questions:

1) Why would the 6513 would top out, from a design perspective, at less than 30 10-GE ports if we were using X2 modules instead.

2) If we're using Supervisor 720 engines (720-Gbps backplane) and this provides 48-Gbps per slot, why again would there be such a limit?

Thanks in advance for hopefully somewhat-detailed answers to these two...

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Actually found it in the doc you provided.  If you look at second document and search on "slot requirements" you can see that the cards can go into any slot in the 6509 or 6509E, but in the 6513 they can only go into slots 9-13.

So on the 6509/E you can have 7 cards, but in the 6513 you can only have 13.  Fewer cards, so fewer ports.

I will have to see if I can find it, but there are different types of slots in the 6500 and not all line cards can be put in all of the slots.

My guess is that the 6513 was designed to high port count for "slower" ports (1 Gbps and below) and so not all of the slots can support the higher speed cards.

However, I would have expected the 6513 to support at least as many high speed ports as the 6509.
Don JohnstonInstructorCommented:
On the 6513, only slots 9 - 13 are "dual-channel" fabric capable. Slots 1 - 8 are "single-channel" with half the bandwidth (about 24gbps per slot).

On the 6509, all the slots are "dual-channel".

cardsfan73Author Commented:
Thanks guys - I gave giltjr the bulk since he did point me to the correct answer first, but the dual-channel input by don helped me find a great architecture doc on these.

Thanks again!
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