[HELP/EXPLAIN]Delays, beeping, fax.. ?connected? to zttest

Hello.

    My problems with calls to PSTN started from strange during-conversation-growing delays. I.e. at the beginning of conversation delay is ~ 0.3 sec - after 5min it can become 1 - 2sec. The more interesting thing is that delay growth is preceded by some strange beepinng sound (as I undarstand it now - this sound is consequence of lost voice packets, but to be more laconic i'll call this process just by "beeping").
    The delay problem was eliminated by choosing SJphone as my softphone (but it still persists for Idefisk, X-Lite(EyeBeam) - so it's rather protocol-independent trouble), but the "beeping" is still exists...
    The next rake I stepped on was Fax recieving - everything seemed fine - fax is succesfully detected, fax extension is processed, rxfax recieves fax. But. The page is incomplete - I've red some posts and FAQ's (the most helpful was one from [www.soft-switch.org](http://www.soft-switch.org)) and came to thought that the problem is in "beeping" itself.

    The worst thing I was able to monitor by Zapata tools was zttest results, but from other point - I don't get what they mean hence I can't 

estimate their magnitude and how to make them better.
All I’ve read on this question was related to software manipulations i.e. stop X server, turn off USB ports… I will try this methods, but the deeper i dig the more magic actions I discover. I would be very glad if somebody put me on earth by explaining, i.e.: zttest results their dependences, what they monitor and how to fight for their improvement;

Zttest results:
— Results after 447 passes —
Best: 100.000000 – Worst: 9.448242 – Average: 96.269829

My configuration is following: TDM400P (3 FXO 1 FXS), ASUS K8V-MX, Semtron 2600, 512 RAM
Asterisk 1.2.10, zaptel 1.2.7 running on Suse 10.1 x64

Thanks alot.
WBR.

Hi, again.

Now my “new” results:

I’ve stopped USB, turned off parallel ports, turned off X-server. Zttest showd me this(it was running whole night) :

– Results after 58831 passes —
Best: 100.000000 – Worst: 5.969238 – Average: 96.271301

This is neither 99.98 nor 99.97.

My next step was to switch motherboards (i’ve got just the same one) - result is the same.

Now, additionally, I have following question: is it possible that the problem is in Built-in digium timer, and is there any way to switch to ztdummy to compare results of test (I haven’t try to recompile zapata drivers with ztdummy, for now - it’s the next step, btw I think just compiling them wouldn’t be enough to switch timer)

My next step will be to try it on different computer with SuSE 10 x32 on it, and I’m still asking for any guide/advice or just explanation of what I’ve encountered.

Thnx in advance…