VoIP QOS

[bryantsteve]

Need help in understanding where to apply VoIP QOS on my VPN network. Using C2800 routers with a private networks behind the non IP address 0/1 interface the Voice, data and management subnets are subinterfaces  eg 0/1.1 data, 0/1.2 voice, etc.. The IPSEC VPNs are mapped to the outside interface 0/0. I need to be able to prioritize the traffic going out the VPN to prefer VoIP but I am not sure where/how to apply the QOS polcies generated by the VoIP auto QOS feature. Thanks

[Jason Gervia]

Hello,

Not sure what your exact configuration is, but typically QOS would be applied to the unencrypted traffic vs encrypted.

Try looking at this:

http://www.cisco.com/en/US/tech/tk543/tk545/technologies_tech_note09186a008017405e.shtml#charactrafficqos

--Jason

[bryantsteve]

Thanks Jason

Site to Site VPN network,  Basically config looks like this

crypto map XXXX 10 ipsec-isakmp

interface FastEthernet0/0

Real Internet Address
crypto map XXXX

interface FastEthernet0/1
no ip address

interface FastEthernet0/1.1
description data
encapsulation dot1Q 10
ip address 10.X.X.X.1  255.255.255.0

interface FastEthernet0/1.2
  description VoIP
  encapsulation dot1Q 10
  ip address 10.X.X.Y.1  255.255.255.0

.....

h323-gateway voip bind srcaddr

So would I apply QOS to the 0/1 interface and prequalify on the crypto map interface to enforce  VoIP QOS on the unencrypted private network?

[Lei Tian]

Hi,

QoS queuing is happen on the WAN interface, fa0/0 on your case; QoS marking is happen on the LAN interface, fa0/1.1 and fa0/1.2 on your case.

HTH,

Lei Tian

[bryantsteve]

Thanks Lei,  one more question if you would please,  how do I utilize the auto qos voip feature on these interfaces to create the QOS  configuration ?

[Jason Gervia · Accepted solution]

If you put pre-classify on the crypto map, you can apply QOS settings on the outgoing interface based on the pre IPSEC encapsulated headers.

[bryantsteve]

OK I think I've got a good idea now how to proceeed thanks for the help!