Best place to apply QOS

[roger perkin]

I would like to limit the bandwidth used by a host at a remote site but only to a specific server.

Where is the best place to apply the policing?

1: the Core switch that the server is plugged into

2. The Wan switch

3. On the service provider router (have to pay!)

4. on the remote switch

Also is policing the best way to go - I just want to limit user to specific server to 1Mb

Thanks

Roger

[Shashank Singh]

Hi Roger,

Policing can be done on any of the above devices mentioned. However, there are two best practices when it comes to policing:

++Policing should be done as close to the source as possible.

++Whenever possible, policing should be done in Catalyst hardware rather than Cisco IOS Software.

If we go by the above guidelines, the best place to police the traffic is the 3750 switch to which host (traffic source) is connected. Please be informed that 3750 platform supports policing in hardware and only on ingress.

Let me know if there are more questions and please rate this post if your query is answered.

Regards,

Shashank

[roger perkin]

Shashank,

If you say the best place to apply QOS is as close to the source as you can - why not the 6509?

If a user is requesting a lot of traffic from the server - is the server the source?

Thanks

Roger

[Shashank Singh]

Hi Roger,

Yes server is the source for the return traffic. However if you apply the policer on the 6509 near the server, only the server data will be policed to less than 1 Mb. If data from server is the only data that is coming to the host, this will be as good as having the policer near the host. But if the host is accessing other resources also, say internet, then total ingress at the server may be more than 1 Mb.

Hope that was helpful.

Regards,

Shashank

[Joseph W. Doherty]

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Posting

Also is policing the best way to go - I just want to limit user to specific server to 1Mb

Assuming the problem is you don't want this particular server impacting other traffic if it generates lots of traffic, I would suggest deprioritizing its bandwidth usage so it effectively only has access to unused bandwidth.