Possible QoS issues

[olbs]

Good morning,

After a bit of research on the topic I've enabled some QoS between a 1721 and 2610 for VoIP, but the customer is still saying some calls are noisy. I've listed the commands and output of "sh policy-map int e0" from the 1721, the 2610 has the same settings and output. I'm thinking the point to point wireless link is a bit dodgy and dropping the voice UDP but am unable to prove this.

Basic network diagram is VoIPPBX <-> 1721 <-> WirelessAP <-> WirelessAP <-> 2610 <-> PoE switch with IP handsets.
Any ideas? I can see in the "sh pol int e0" that the link is getting congested and class-default traffic is getting dropped intentionally

!
!
class-map match-any VoiceTraffic
match access-group 100
!
!
policy-map VOIP
class VoiceTraffic
priority 2000 100000
class class-default
fair-queue
!
!
interface Ethernet0
ip address 10.0.8.4 255.255.255.248
half-duplex
service-policy output VOIP
!
interface FastEthernet0
ip address 10.0.2.1 255.255.255.0
speed auto
full-duplex
!
router eigrp 1
network 10.0.0.0
auto-summary
no eigrp log-neighbor-changes
!
ip classless
ip route 0.0.0.0 0.0.0.0 10.0.2.254
no ip http server
!
!
access-list 100 permit ip any any dscp af41
access-list 100 permit ip any any dscp ef
!

sh pol int e0
Ethernet0

Service-policy output: VOIP

Class-map: VoiceTraffic (match-any)
2346565 packets, 171280838 bytes
5 minute offered rate 5000 bps, drop rate 0 bps
Match: access-group 100
2346565 packets, 171280838 bytes
5 minute rate 5000 bps
Weighted Fair Queueing
Strict Priority
Output Queue: Conversation 264
Bandwidth 2000 (kbps) Burst 100000 (Bytes)
(pkts matched/bytes matched) 8308/607390
(total drops/bytes drops) 0/0

Class-map: class-default (match-any)
9151587 packets, 7780780143 bytes
5 minute offered rate 27000 bps, drop rate 0 bps
Match: any
Weighted Fair Queueing
Flow Based Fair Queueing
Maximum Number of Hashed Queues 256
(total queued/total drops/no-buffer drops) 0/4277437/0

 

[AzharMirza]

Hello,

Few tips:

1. Setup Cisco IP SLA to monitor 1way delay (should be <150msec), jitter (should be less than 30msec) , pkt loss(should be < 1%) and Voice MOS (> 4) to btn two routers. Try this with/without VoIP traffic.
If IP SLA stats are not as mentioned above then the link is NOT suitable for VOIP.


2. Set up ip nbar protocol discovery on both interfaces to monitor what applications are taking bandwidth & what is rate.

3. Make sure all VoIP traffic is pre marked as EF & AF41 as you have set. If not use match protocol RTP.