topic Re: distorted voice in Voice over IP

distorted voice

biao-shen — Fri, 10 Jan 2003 05:36:49 GMT

hi,

we use E&M signal like : tel ---PBX----E&M---router----WAN------router----E&M----PBX---tel,

sometimes the voice quality is very good , sometimes it is too bad to understand, the configration is same and not for the reason of bandwidth.

the operation 4-wire , type V.

i need some advices.

BRs

Re: distorted voice

electro22 — Thu, 16 Jan 2003 19:21:11 GMT

Do you have a QoS policy in place on your WAN?

Re: distorted voice

lourenco — Thu, 16 Jan 2003 23:01:16 GMT

Hi,

You have to perform a traffic analysis on your network to identify the reasons for poor voice quality. Anyway, as you said the problem is not constant, look for bursty traffic on the wan, like ftp, file transfers, backups, database synchronization, etc. If that is the case and you can't eliminate the cause, implement QoS to manage the bandwidth distribution among the services and protocols. Custom queueing combined with packet fragmentation (lower MTU) and RTP header compression often give excellent results.

The problem has nothing to do with signaling.

Regards,

Luiz Lourenço

Re: distorted voice

sureshkumarv — Fri, 17 Jan 2003 12:39:33 GMT

hi,

it is due to high network traffic only. so check for valid data is transfered or some other noise is generated. it can be viewed by the " sh int ser x ".in this report verify the input errors, crc and frames.may be due to virus and network card.

rsu

Re: distorted voice

kmcsweeg — Sat, 01 Mar 2003 02:48:20 GMT

Has this been the case since installation?, if so you may want to move to newer code, i had similiar issues with quality that disappeared with a code update, i went from 12.2(13a)T1 to 12.2(16.1)T, Routers in cloud are 3662's

3640's.2612's.

Kevin