distorted voice

[biao-shen]

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

[benng]

Hello,

Although you have mentioned that bandwidth is not a problem, a good place to start is to make sure there are sufficient QoS configuration for your two routers connected by WAN and make sure that RTP packets are properly prioritized.

Please see below for LLQ configuration for PPP leased lines or Frame Relay.

http://www.cisco.com/en/US/tech/tk652/tk701/tech_configuration_examples_list.html

-ben