Cisco Unity Express QoS with CME
Configuring QoS between CUE and CME requires identification and re-marking of packets that match the following criteria:
- Payload: RTP (i.e. UDP > 16384)
- Signaling: SIP (TCP 5060)
CUE actually already marks RTP traffic as DSCP EF, and signaling (SIP) as DSCP AF31, however best practice dictates that we will make traffic on the service policy ingress. In fact, look at the access-list counters iterate when applied to the service-engine interface (this is before any QoS marking is applied - we simply apply an ACL to verify traffic characteristics):
CME#sh ip access-lists 115
Extended IP access list 115
10 permit ip host 192.168.255.98 any dscp af31 log (8 matches)
20 permit ip host 192.168.255.98 any dscp ef log (409 matches)
30 permit ip any any (27 matches)
The following configuration provides ingress QoS marking from CUE to CME.
class-map match-all sip
 match protocol sip
class-map match-all rtp
 match access-group 120
class-map match-all default-catch-all
!
!
policy-map cue
 class sip
  set ip dscp cs3
 class rtp
  set ip dscp ef
!
interface Service-Engine1/0
 service-policy input sip
Now, make a call to CUE from any phone registered with CME. Notice the packet counts increment on the service-policy. Ensure you specify the interface to confirm hit counters. What's interesting is that the catch all "class-default" sees hits; on closer investigation, there is some unexpected traffic:
Jan 27 09:40:53.199: IP: s=192.168.255.98 (Service-Engine1/0), d=192.168.255.99, len 128, rcvd 4
Jan 27 09:40:53.199: ICMP type=3, code=3
ICMP type 3 code 3 - Port unreachable errors! Weird. Might just be something about my configuration, however my setup is pretty simple. Anyway, I digress... The next step is to verify hits on the ingress policy-map.
CME#sh policy-map interface service-Engine 1/0
 Service-Engine1/0
  Service-policy input: cue
    Class-map: sip (match-all)
      17 packets, 7445 bytes
      5 minute offered rate 0 bps, drop rate 0 bps
      Match: protocol sip
      QoS Set
        dscp cs3
          Packets marked 17
    Class-map: rtp (match-all)
      860 packets, 182808 bytes
      5 minute offered rate 0 bps, drop rate 0 bps
      Match: access-group 110
      QoS Set
        dscp ef
          Packets marked 860
    Class-map: class-default (match-any)
      122 packets, 91969 bytes
      5 minute offered rate 0 bps, drop rate 0 bps
      Match: any
That's all there is to it. Applying quality of service to an NM-CUE/AIM-CUE is identical to applying QoS on more "traditional" fixed interfaces.
