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New Member

Default Codec on 7912G

Running Callmanager Express 3.3 on 2800 hardware. When calling between sites, using 7960 handsets, quality of call is perfect, using 7912G to 7960, very poor quality. I have read that the 7912G defaults to G.711 codec unless you enable g.729. Can anyone confirm this, and if thats right, how do you change it (profile ? webpage ?)

Thanks

7 REPLIES
Bronze

Re: Default Codec on 7912G

All devices in your CME group should use the same codec as set in the DSPfarm. 7912, 7940, 7960, etc.. should not vary unless they are in a different CME group.

The command should be

Router(config-dspfarm-profile)# codec g711ulaw

I believe this to be true in 3.3, as the doc indicates transcoding for g.729 was only between two-party calls in 3.2 and prior.

http://www.cisco.com/en/US/customer/products/sw/voicesw/ps4625/products_configuration_guide_chapter09186a00804ad867.html

Hope that helps.

Tom

New Member

Re: Default Codec on 7912G

Sorry, perhaps I didnt make it very clear. The problems are between 2 CME system, over a wide area link. I assumed that selecting the codec in the dial-peer statement was enough to ensure that g729 was used, but I dont think it is - hence the quality problems.

Anything anyone can add to that ?

Bronze

Re: Default Codec on 7912G

Did you configure the router in global mode to use 729 also?

Try this:

Router#conf term

Router(config)#voice class codec 99

Router(config-class)#codec preference 1 g729r8

Router(config-class)#codec preference 2 g711ulaw

Router(config-class)#end

Then assign 729 to the dial-peer as well.

See if that helps.

New Member

Re: Default Codec on 7912G

Thanks, I will apply and test. Do you know any way of checking the codec used in an active call ? (sorry if thats a stupid question)

Pete

Bronze

Re: Default Codec on 7912G

Pete:

Use 'sho call active voice' on the router from privileged mode.

... and I was told by a very wise man once that the only stupid question is the one that doesn't get asked.

Tom

New Member

Re: Default Codec on 7912G

Oh :( that blows that idea then; looks like we are using 729r8, so thats not my problem. Still cant understand why calls between 7960's are working but calls to 7912's are jittering.

output from show command:

Router# sho call active voice

Telephony call-legs: 1

SIP call-legs: 0

H323 call-legs: 1

Call agent controlled call-legs: 0

SCCP call-legs: 0

Multicast call-legs: 0

Total call-legs: 2

GENERIC:

SetupTime=1868195990 ms

Index=1

PeerAddress=771

PeerSubAddress=

PeerId=20001

PeerIfIndex=39

LogicalIfIndex=38

ConnectTime=1868200590 ms

CallDuration=00:00:46 sec

CallState=4

CallOrigin=2

ChargedUnits=0

InfoType=speech

TransmitPackets=0

TransmitBytes=0

ReceivePackets=1150

ReceiveBytes=46000

TELE:

ConnectionId=[0x58CEC485 0x4CA311DB 0x833B8EBE 0x6294392]

IncomingConnectionId=[0x58CEC485 0x4CA311DB 0x833B8EBE 0x6294392]

CallID=516

TxDuration=39320 ms

VoiceTxDuration=39320 ms

FaxTxDuration=0 ms

CoderTypeRate=g729r8

NoiseLevel=0

ACOMLevel=0

OutSignalLevel=0

InSignalLevel=0

InfoActivity=2

ERLLevel=0

SessionTarget=

ImgPages=0

CallerName=Pete Moore

CallerIDBlocked=False

OriginalCallingNumber=771

OriginalCallingOctet=0x0

OriginalCalledNumber=

OriginalCalledOctet=0x80

OriginalRedirectCalledNumber=

OriginalRedirectCalledOctet=0x0

TranslatedCallingNumber=771

TranslatedCallingOctet=0x0

TranslatedCalledNumber=

TranslatedCalledOctet=0x80

TranslatedRedirectCalledNumber=

TranslatedRedirectCalledOctet=0x0

GwCollectedCalledNumber=100108

GwReceivedCallingNumber=771

GwReceivedCallingOctet3=0x0

GwReceivedCallingOctet3a=0x0

Telephony call-legs: 1

SIP call-legs: 0

H323 call-legs: 0

Call agent controlled call-legs: 0

SCCP call-legs: 0

Multicast call-legs: 0

Total call-legs: 1

The number of call legs at the end of the show process

is not equal to the initial count. Some call-legs were

terminated or created during the viewing process.

Number of call-legs counted during viewing: 1

Bronze

Re: Default Codec on 7912G

Pete:

This may seem strange to ask, but we ran into it once. Are your user's network ports nailed-up to a specific speed and duplex?

The 7912G is not able to be hard set to a speed or duplex - auto is the only option. The 7940/60G is able to be set and, as a result, reduced the duplex mismatches we were getting in our environment. Call quality improved, too.

Just a thought.

Tom

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