3-way Calling - CallManager

[cmatiella]

Hello-for some reason the 3-way calling feature on my CallManager 3.3 is not working anymore. I get a fast busy after I dial the 3rd party and press the conference button to connect them. We're using Cisco IP 7960 IP phones. The feature has been installed for a few years and has been working properly. Where do I even begin my trouble shooting?

[Jaime Valencia]

could be a codec issue since it happens after the 2nd conference push

HTH

java

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[cmatiella]

Hi,

Thanks for your reply. I know nothing about the CCM, codec, etc. I don't know where to look for a codec issue. I've checked the server for error messages and did not find any. Do you know of a good resource that I may use to trouble shoot this? Like I said. 3way calling has been set up and working for a few yrs and then it stopped working. I do know that a change was made on our call manager that switched the compression algorhythm from G711 to G729.

Thanks for your response,

CEM

[Jaime Valencia · Accepted solution]

ok, there is no need to troubleshooting you just answered why this is not working. i bet you're using the SW CFB which only handles G711, if you plan to use it you need to switch to G711, OR use HW CFB

go to region, there you set the codec, the region is set at device pool, device pool to devices. change it

HTH

java

if this helps, please rate

[cmatiella]

Hi,

It appears that you were absolutely correct. One of my vendors (who doesn't know much about the call manager) had switched the settings to G729 so that calls would use less bandwidth. How do I find information about switching to hardward CFB and exactly what's involved with configuring it.

Thanks,

CEM

[Jaime Valencia · Accepted solution]

Configuring Enhanced Conferencing and Transcoding for Voice Gateway Routers

http://www.cisco.com/en/US/docs/ios/12_3/vvf_c/interop/intcnf2.html

DSP Calculator

http://www.cisco.com/cgi-bin/Support/DSP/cisco_dsp_calc.pl

CCO needed for the above link

CallManager and IOS Gateway DSP Farm Configuration Example

http://www.cisco.com/en/US/products/sw/voicesw/ps556/products_configuration_example09186a0080334294.shtml

Once you have it it's just a matter of playing around with the MRGL and MRG to have phones use it.

HTH

java

if this helps, please rate