Best QoS technique to reserve fixed bandwidth for an application

[pradeep.s]

Hi all,

One of my clients has a 64 Kbps Leased Line with ppp encapsulation between his HQ to it remote branch. The routers at HQ being 3660 series (IOS ver 12.1) and remote branch being 1750 series (IOS ver 12.1). The clients in the remote branch are running certain application accessing data from the server located at HQ. There are also other application traffic running between HQ and RO. The customer need is to reserve minimum guaranteed bandwidth of 15 Kbps for this application, at the same time this bandwidth allocated should not exceed 15 Kbps during non-congestion.

Now my question is how do I restrict this application to use only 15 Kbps of bandwidth on a 64 Kbps link irrespective of other traffic flowing across the HQ and Remote branch ? The remaining bandwidth available should be utilized by other traffic.

Is class based weighted Fair queuing with priority of 15 Kbps bandwidth suitable for this QoS implementation ?

Your suggestions are welcome !

Thank you

Pradeep

[bbranch]

If you need to restrict the bandwidth used by the app at all times to 15Kbps even if the link is not congested your best bet is either Committed Access Rate (CAR) or Generic Traffic shapping (GTS), CAR will police your traffic to 15Kbps and GTS wil shape your traffic to 15Kbps

CAR - http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/fqos_c/fqcprt1/qcfcar.htm

GTS - http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/fqos_c/fqcprt4/qcfgts.htm

[pradeep.s]

Thank you for that link, its really helpful one.

In the CAR technique, what if I set the normal burst and excess burst to zero and average rate across the link for that application to 15000 bps? Still I will get the commited rate of 15 Kbps for the application ?

thanks and regards,

Pradeep