[asterisk-users] PRI debugging ...

[Gordon Henderson]

On Fri, 16 May 2008, Gordon Henderson wrote:

> Have a problem with an ISDN30 line in the UK.

So following up my own post.. I've not solved this issue, but I think I 
know what causes it.

This was my experiment to put 2 cards in one 1.3GHz system - a TDM400 with 
2 x FXO and 2 x FSX and a TE120P - E1 card.

The PRI card loses interrupts, so I'm guessing it loses a frame of data 
when it loses an interrupt, and eventually it gives up and does a reset. 
The TDM card was rock solid. The system is using oslec too FWIW.

When I unloaded the wctdm module the PRI performend flawlessly.

So I'm suspecting the 1.3GHz processor and underlying IO is marginal for 
this application. The Mobo doesn't have an APIC, just old PIC hardware, 
although both cards were on separate IRQs - the TDM card had the higher 
priority IRQ though - didn't have time to test it with the cards swapped 
over, but loading the modules in a differnt order didn't make any 
difference. Turning off the USB hardware didn't help either.

The processor does seem to have a highish high-priority interrupt load (as 
seen by top). I'll be trying a newer kernel when I get a chance though 
(this is 2.6.18, compiled to match the motherboard exactly)

Making calls through the TDM card just made it worse.

However when it was working, it was working very well indeed, but the 
occasional time when it dropped all calls (about once an hour) wasn't 
good.

Gordon