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Bronze

SERIOUS VOICE QUALITY ISSUES

HELP,

having some serious voice quality issues with my customer. voice is missing, if i call into the auto attendant im not hearing complete sentences etc. internally it isnt working properly as well. im posting the running config for the router. any help would be greatly appreiciated.

7 REPLIES
Bronze

Re: SERIOUS VOICE QUALITY ISSUES

i must say also that it is intermittent, cause i just called in to check again and the voice quality was perfect.

Hall of Fame Super Silver

Re: SERIOUS VOICE QUALITY ISSUES

When do you have the quality issues? When you call remote phones, phones at the same site? What is your topology, where is the callamanager?

I did notice from the config that you did not apply the LLQ service-policy Link_CCTT to any of the frame subinterfaces, only to the ethernet interface. You need to apply is to the serial interfaces!

Also, in your policy-map you have

policy-map Link_CCTT

class voice

priority percent 60

class voice-sig

bandwidth 96

if you use percentage for one class you need to do the same for all others, change it to

policy-map Link_CCTT

class voice

priority percent 60

class voice-sig

bandwidth percent 5

Then run the following command:

sh policy-map interface serial x/x

to check if packets are matched correctly!

Read the QoS SRND www.cisco.com/go/srnd for further QoS configuration.

Rate all helpful posts!

Chris

Bronze

Re: SERIOUS VOICE QUALITY ISSUES

Everyone correct me if I am wrong.

I just read through your config briefly.... I saw it is frame-relay configuration, also I assume it is a huh and spoke design. The router seems like at Central site if I am not mistaking.

take your one of your map-class for an example:

map-class frame-relay POS_TO_SANDO

frame-relay cir 364000

frame-relay bc 3640

frame-relay be 0

frame-relay voice bandwidth 57000

frame-relay fragment 640

frame-relay fair-queue

service-policy output XXXX---> u should have LLQ under map-class, please put that at both end.

Create more LLQ for different bandwidth between site, it is because each site has different CIR.

Talking about your internal voice issue. Please make sure your layer 2 (switch) marking correctly.

Take 3550 for example:

Global:

1. mls qos

2. mls qos map cos-dscp 0 8 16 26 34 46 48 56

3. mls qos map ip-prec-dscp 0 8 16 26 34 46 48 56

Interface command (IP Phone):

1. interface fastethernet 0/1

2. mls qos trust cos

3. mls qos trust device cisco-phone

4. priority-queue out

5. wrr-queue cos-map 4 5

6. wrr-queue bandwidth 1 2 3 4

7. spanning-tree portfast

8. switch-port access vlan 2 -->Data

9. switch-port voice vlan 6 --> Voice

Interface command (connect to router)

1. interface fastethernet 0/24

2. mls qos trust dscp

3. priority-queue out

4. wrr-queue cos-map 4 5

5. wrr-queue bandwidth 1 2 3 4

Please rate this post if it helps. Let me know.

Thanks

Ken

Bronze

Re: SERIOUS VOICE QUALITY ISSUES

sorry i wasnt that specific,

initially they did have a frame-relay hub-/spoke config that we were using for VOIP. they then went to fibre to all the locations therefore removing the physical frame connections.

the voice quality issue seems to be internal as well as external, worse from external though.

ive attach a diagram of the present network for a better understanding.

honestly, as you might figure by now, QOS is beating me. i really need to be well versed with QOS.

Bronze

Re: SERIOUS VOICE QUALITY ISSUES

GOODING,

Your problem is a very board... That best thing for you read QoS SRND like Cederen mention.

But you can use these command to start your troubshoot:

show policy-map interface serial/ethernet/fastethernet x/x

to see any packet match at your LLQ.

Use show interface serial/ethernet/fastethernet x/x

to see any output drop, queue or error.

If there is no voice problem before move from frame-relay to fiber. The problem might caused by fiber connection or QoS at fiber.

Thanks

Ken

Bronze

Re: SERIOUS VOICE QUALITY ISSUES

makes sense and please bear with me,

im reading the pdf right now and will be going to the customer. however, im not seeing it as a "WAN" issue per say. it is and issue residing only at this head office. here is the scenario

i call into the router from the PSTN, i reach the ipcc and hear my prompts, my prompts are broken. when transfered to an agent, the quality is better but not ideal. now if i work with this scenario, it means that the call enters the router, goes to the LAN and then the callmanager and then to the ip phone when available. the voice therefore passes from the router, then to the ehternet interface connected to the lan then to the call manager. Therefore, my issue resides on the ethernet interface of the router to the LAN and/or the connection from the switches to the call-manager.

although im seeing that the QOS is not configured optimally on the WAN interfaces, am i not by passing that since my router is the first point of contact calling from the PSTN. as well, can it probably point to an issue within the network itself?

again, reading the pdf and ill see how it goes.

thanks a million for the replies.

Bronze

Re: SERIOUS VOICE QUALITY ISSUES

makes sense and please bear with me,

im reading the pdf right now and will be going to the customer. however, im not seeing it as a "WAN" issue per say. it is and issue residing only at this head office. here is the scenario

i call into the router from the PSTN, i reach the ipcc and hear my prompts, my prompts are broken. when transfered to an agent, the quality is better but not ideal. now if i work with this scenario, it means that the call enters the router, goes to the LAN and then the callmanager and then to the ip phone when available. the voice therefore passes from the router, then to the ehternet interface connected to the lan then to the call manager. Therefore, my issue resides on the ethernet interface of the router to the LAN and/or the connection from the switches to the call-manager.

although im seeing that the QOS is not configured optimally on the WAN interfaces, am i not by passing that since my router is the first point of contact calling from the PSTN. as well, can it probably point to an issue within the network itself?

again, reading the pdf and ill see how it goes.

thanks a million for the replies.

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