Need to reserve bandwidth when certain IP in use

mark · ‎02-06-2008

Cisco 1841 router connected up to a T1. Router is subnetted on the two interfaces with one of the interfaces going to a Cisco PIX and the other one goes directly to a Polycom teleconferencing device.

We want all 1.5mbit available EXCEPT when the Polycom is in use. When the Polycom is in use, we would like to have the router always give it 384/384. 99% of the time the Polycom is off.

Is there a series of commands to do this?

Edison Ortiz · ‎02-06-2008

You need to implement QoS. Documentation can be found at http://www.cisco.com/univercd/cc/td/doc/product/software/ios124/124cg/hqos_c/index.htm

HTH,

__

Edison.

mark · ‎02-06-2008

So it's a little more than a few commands I take it?

Edison Ortiz · ‎02-06-2008

Most definitely, it's more like a 'project'.

You need to classify the traffic you want to allocate bandwidth to - you need to mark this traffic and then apply a policy to it.

You have 2 option, bandwidth allocation or policing.

Reading the documentation I provided is the best bet.

Joseph W. Doherty · ‎02-06-2008

Might be done easily (depending on interface type) to do outbound with CBWFQ; issues doing inbound. Inbound best done on far side's outbound. Special consideration when working with "cloud" WANs, e.g. frame-relay, ATM, MPLS; i.e. what happens within cloud.

For CBWFQ approach, first identify Polycom traffic, within a class-map. Can be done many different ways, one of which might be using ToS markings if Polycom marks its traffic.

Second define policy map reserving 384 (or same %).

Apply service policy to outbound interface.

e.g. perhaps something like this

class-map polycom

match ip dscp af41

policy-map yourname

class polycom

bandwidth 384000

serial #

service policy yourname output