qos question

kope · ‎10-01-2009

I wonder if i need to implement qos under this situation?

SiteA-3825 - 1 gig ethernet interface

SiteB-6509 - 1 gig ethernet interface

I am connecting SiteA and SiteB by using a service provider ethernet link which has a 20 meg bandwidth (cir).

1. Since the interface is 1 gig and the link is 20 meg, Do i need to implement qos (traffic shaping)? The bandwidth usage between these two sites are expected to be 8 meg usage.

2. If it require traffic shaping; what command would be best for the 3825 and 6509? Can MQC apply?

Please advise.

Giuseppe Larosa · ‎10-01-2009

Hello Peter,

1) yes shaping just below service provider contract is recommended to adapt traffic to circuit characteristics.

2)

C3825 can use MQC for sure, in the case of C6509 the configuration depends on the type of linecard the GE port belongs to.

I'm afraid some types of linecards don't allow you to shape on C6500.

Hope to help

Giuseppe

Joseph W. Doherty · ‎10-02-2009

Do you need to shape?

You should check with your service provider what happens if you oversubscribe. If they drop such traffic, shaping would be a good idea.

As Giuseppe notes, 6500 Ethernet port QoS features are very dependent on line card. The 6500 "WAN" cards are pretty well featured for QoS, but if you don't have one, you might fine it less expensive to drop another device between the 6509 service provider. Depending on your needs, an 8 port 2960 can provide some very basic QoS (would work best if handoff were 100 Mbps, though). Otherwise, you could drop in another ISR. For gig interfaces and up to 20 Mbps duplex, a 2821 would suffice.