[c-nsp] Guaranteed bandwidth THROUGH our network

[Oliver Boehmer (oboehmer)]

Rick Kunkel <> wrote on Wednesday, March 21, 2007 6:40 AM:

> Hello,
> 
> Hypothetical situation here, which will become real in fairly short
> order: 
> 
[...]
> 
> The premium customer wants a guaranteed 50 Mbps to the Internet, at
> least as far as we have control over.  So, if possible, I need to
> make sure that if there is contention for bandwidth across these 2
> traversed Gigabit links, his is a minimum of 50 Mbps.

Use DiffServ QoS. Create a "Premium" class and reserve the required
bandwidth (i.e. number_of_customers * 50 Mbps) through your network
using the available mechanisms (depends on the platform, i.e. WRR for
Cat6k, CBWFQ for 7200 or other central SW platforms, MDRR for GSR,
etc.).
Use a policer at the edge to enforce the SLA, i.e. mark the traffic with
the "Premium" DSCP/Precedence value as long as it's below 50Mbps, and
re-color exceeeding traffic to a different class/drop precedence
(out-of-contract Premium). Map the different drop precedence to a
different RED threshold in your core so you'll drop the out-of-contract
traffic earlier in case the "Premium" queue fills up. 

This is direction Customer --> Internet. The other direction is much
more complicated as you'll receive the Internet traffic through a single
interface, so you can't really police there except if you look at the
destination address (i.e. the customer) and apply multiple policers on
the Interface to enforce the SLA and perform the "out-of-contract"
re-coloring..

Which platforms do you use? QoS can be complicated..

	oli