[Asterisk-Users] Re: Problems with TDM400P card

[Steve Underwood]

Rich Adamson wrote:

>>>I am new to Asterisk, but so far, having looked at this thread (which is
>>>quite long and full of lot's of hard work), the zttest code, the Digium web site,
>>>and the spandsp website, and having talked to Digium sales/support about
>>>the TDM, I think the issue belongs the spandsp community.  They may be
>>>able to point out an improvement to the TDM product that Digium may or
>>>may not implement.  Or they may need to adapt to an improvement on new TDM
>>>cards. It does not appear that Digium has promised support to
>>>the spandsp add-on function to Asterisk. I also didn't see where the spandsp
>>>project was committed to staying up to date with each new revision of
>>>TDM card - that's what the community is for.
>>> 
>>>
>>>      
>>>
>>Then you think wrong. This is totally unrelated to spandsp. Any FAX 
>>machine, modem, or other timing critical device has the same problems 
>>with these cards. Something is broken, and since it used to work OK with 
>>the hardware I am using now I assume it is the TDM driver.
>>    
>>
>
>Steve, is there anyway that you might be able to help us out to identify
>the source of the issues?  I'd really really love to get spandsp working
>with the TDM card; pretty please!
>
>I can give you remote access to a machine with the latest TDM card in
>it if you need.
>  
>
Well, I was thinking of writing a test something like this.

- don't plug anything into the TDM card, so the hybrid echo will be 
maximised.
- send and receive audio, so the echo of the transmitted signal will be 
received.
- send a signal where phase hops will show up easily, and look for any 
hops in the received signal.

This could run quite simply, and report every hiccup. I still need 
something more general purpose to ease support issues, though. The main 
support activity I have with spandsp is dealing with people who have 
slips. Despite trying to publicise the issue adequately, they still 
bother me with the problem and feel they absolutely must have things 
right. Well, the reality is many have E1/T1 lines with the clocking set 
wrong, and I need some automated test to identify those. The reality is 
also that many people having inadequate hardware, or are running X11 and 
loosing interrupts. I also need an automated test to find those. Lastly, 
people with TDM cards just have trouble, and we need to sort this out. 
It seems without a simple repeatable way to show up the problem, it 
isn't going to be fixed.

Regards,
Steve


Regards,
Steve