[asterisk-dev] PSTN Hangup Problem with Asterisk

[leo at datvoiz.com]

Quoting Chan Kwang Mien <kwangmien at asgent-tech.com>:

> Hi,
>
> sipphone <--> Asterisk <--> PSTN <--> Cell Phone
>
> Cell Phone calls sipphone. When Cell Phone hangs up,
> Asterisk shows "Hangup Zap/1-1" immediately.
>
> However, there is hangup problem for the following case :
>
> sipphone calls Cell Phone. When Cell Phone hangs up, it took about
> 1 minute for the message "Hangup Zap/1-1" to show up.
>
>> From the debug logs of wctdm, I could see the following immediately.
>
> Aug 16 16:41:03 localhost kernel: 70132 Polarity reversed (-1 -> 1)
> Aug 16 16:41:43 localhost kernel: 80319 Polarity reversed (1 -> -1)
>
> My guess is that the hangup is detected immediately by the wctdm driver.
> But Asterisk wasn't able to detect the hangup immediately. Could it be
> that wctdm did not inform Asterisk of the Hangup ?

Are you using loopstart or kewlstart? If you're in Singapore, you  
should use loopstart. From my own experience, kewlstart partly works  
but can generate strange polarity reversed conditions. During those  
states, Asterisk gets confused about the line's actual state. These  
are the issues I've experienced when using fxs_ks signalling:
a) hangup is not detected, or
b) hangup is detected as a hangup followed by a new call.

Changing the signalling to fxs_ls and using busydetect=3, everything  
went away.

Hope this helps.

Leo