I need to restart the server for call quality sake

Hi,

I have been using Asterisk 1.2.12 for a while and I use it to transfer calls from a Zap channel to another one. My problem is that call quality deteriorates after sometime and one or two party hear acho/noise. I have to restart the server ( restarting asterisk only is not enough). It seems to be a memory problem. Does anybody have any idea how to fix this problem?
I would really appreciate it.

How about more information. What kind of fxo card are you using? Zaptel version?

what run level you are using for Asterisk ?

I am using Openvox 12 port FXO cards together with a D-Link voip gateway.
I forward call from D-link gateway to an fxo port on the openvox card and yes its zaptel version.

Asterisk version: 1.2.12
Zaptel version: 1.2.9.1

How can I know what the run level of asterisk?

Thanks