[c-nsp] Cisco 6509 and Bus speeds

[Tim Stevenson]

At 12:53 PM 1/13/2005, cisco-nsp-request at puck.nether.net averred:
>Message: 1
>Date: Thu, 13 Jan 2005 18:12:20 +0100 (CET)
>From: Mikael Abrahamsson <swmike at swm.pp.se>
>Subject: Re: [c-nsp] Cisco 6509 and Bus speeds
>To: cisco-nsp at puck.nether.net
>Message-ID: <Pine.LNX.4.44.0501131810220.3584-100000 at uplift.swm.pp.se>
>Content-Type: TEXT/PLAIN; charset=US-ASCII
>
>On Thu, 13 Jan 2005, Tim Stevenson wrote:
>
> > This card is not fully non-blocking, but it is nearly (like >98%) line
> > rate on all 4 ports with large packets. You can't ever get full 40G wire
> > ethernet across the fabric, as we add 32 bytes of overhead to every
> > packet.  Also, the fwding engine is the bottleneck at 64B packets, ie,
> > either the sup (30Mpps) or a DFC3 (48Mpps) has less capacity than 4x10G
> > ports (60Mpps).
>
>But in the case of i-mix (avg 300 byte packets) it's able to do at least
>90% of all ports?

Yes.

>  Is there any combination of ports that are bundled
>together asic-wise or channelwise on the 6704, or are all ports equal in
>respect to each other?

Yes, ports 1-2 share one 20G channel to the fabric, and ports 3-4 share the 
other.

For full non-blocking 10G on 2 ports, you use one port from each channel.

Tim


>
>--
>Mikael Abrahamsson    email: swmike at swm.pp.se



Tim Stevenson, tstevens at cisco.com
Routing & Switching CCIE #5561
Technical Marketing Engineer, Catalyst 6500
Cisco Systems, http://www.cisco.com
IP Phone: 408-526-6759
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