QOS

[MAHESH.K]

Hi,

I have been provided 30Mb/s connection by ISP and i want to split the bandwidth 15Mb/s between two different network using QOS. If one of the network is utilizing less bandwidth than allocated Bandwidth ,then other network should utilize maximum available bandwidth.

Im confused how to configure ingress and egress traffic?

difference between CIR and egress committed burst size.

[Georg Pauwen]

Hello,

on ingress, you can only configure policing, so at most you can limit inbound traffic to 15MB max, which is probably not what you want.

Instead of CIR, you could use the 'bandwidth percentage' command. Match both your networks in the respective access lists. Both will be assigned 50 percent of the bandwidth, and if less is used by one network, it will be available for the other network:

class-map LAN_1

 match access-group 101

class-map LAN_2

 match access-group 102

policy-map 30_MB_SPLIT

 class LAN_1

  bandwidth percentage 50

 class LAN_2

  bandwidth percentage 50

service-policy output 30_MB_SPLIT

[Joseph W. Doherty]

Just to re-emphasis what Gpauwen shows for a policy, it can only be used for egress.  If would be great for your traffic to the ISP, not for traffic from the ISP.

As Gpauwen also mentioned, you can police the ingress bandwidth, but beside precluding allowing use of unused bandwidth, it won't always preclude more than half the bandwidth being used before it reaches your policers.

NB: really good management of ingress bandwidth is difficult.  There are dedicated 3rd party traffic management appliances that can help, but even they are not 100% good in all cases.