What’s your timing source?

you need to make sure you have Zaptel (or dahdi) running to use Meetme… if you are not using any digium hardware cards… you still need it and a module called ztdummy will load…

asterisk needs this for the correct timing (clocking) or the sound quality on Meetme calls will be very chip-choppy…



ztdummy is mutually incompatible with dahdi, as it is a Zaptel module.

You need a 2.6 series kernel, in which case it can use the RTC, or a suitable USB controller. If the module is properly loaded, it will find any suitable hardware.

I’m assuming this system isn’t virtual.


Please provide the output of

Also please provide details of the hardware and OS on which you are running, and confirm that you are not using any virtual machine environment.



That basically leaves a network or processor overload.

Are you running anything else on the same (physical) processor? Note that X-Windows can cause significant load problems, so any active X-Windows sessions count here. If just running Asterisk, you should have more than enough processor power.

For the network, the results of

might be useful.

(Incidentally the particular inforamation I was after about the hardware was the USB controllers. However, as you are using the high resolution timer, that has become unimportant.)


Are any clients running over the internet? Verify that your voice is not choppy from poor internet/lan management. (read not utilizing QoS)


I doubt there is anything relevant in dahdi, once you have timing configured, which you appear to have.

No tuning should be necessary, so the problem is trying to work out what is wrong with your system. Until we know what is wrong, it is difficult to say how to fix it.

The fact that u-law works better than other (presumably more heavily compressed) codecs suggests to me that you are running something resource intensive on the same machine, but you haven’t answered any of my questions about that.