Bad voice quality through VIC2B-S/T

[pcobley]

Hi,

I have got major voice quality problems through a 2600 gateway using a VIC2B-S/T.

I have tried :-

New IOS

New NM-1V

New VIC2B-S/T

Different router chassis - 2621 & 2611XM

Different ISDN circuits

Different ISDN cable

Adding the gateway to my own CCM cluster (as opposed to customer's CCM cluster).

So, I've tried pretty much everything but still get really bad voice quality - even ringback is bad.

This isn't even a problem with QoS on the LAN since the gateway is now on our live CCM network where we have a 2600 E1 MGCP g/w and this works fine (and has done for 3 years).

Here's the relevent config :-

=====

isdn switch-type basic-net3

call rsvp-sync

!

interface FastEthernet0/0

ip address 192.168.40.3 255.255.255.0

duplex auto

speed auto

!

interface BRI1/0

no ip address

isdn switch-type basic-net3

isdn incoming-voice voice

!

ip classless

ip route 0.0.0.0 0.0.0.0 192.168.40.1

ip http server

!

voice-port 1/0/0

!

dial-peer cor custom

!

dial-peer voice 9 pots

incoming called-number .

destination-pattern 9T

direct-inward-dial

port 1/0/0

!

dial-peer voice 760471 voip

answer-address 760471

destination-pattern 760471

session target ipv4:192.168.30.3

!

=====

Any help or pointers would be very much appreciated. I really can't think of what else to try.

Thanks in advance,

Paul.

[umedryk]

Hi Paul,

You could check the trouble shooting section under : www.cisco.com/techsupport/---------> Products ----------> Routers ---------> 2600 Series

[pacameron]

add the command 'compand-type a-law' under the voice port 1/0/0

The default coding on the BRI cards is ulaw, so the audio coming in will be all distorted if there is a codng mismatch.

Be aware that if you use a BRI VIC in a NM-1V, you will onl be able to get one port to fuction as there is only 2 DSP resources on the NM-1V card and the BRI VIC can handle 2 BRI ports, or 4 calls.

[pcobley]

Thanks for that Paul - it works !!