[asterisk-users] TDM808B 8 port FXO setting problem

Tzafrir Cohen tzafrir.cohen at xorcom.com
Fri Nov 23 05:35:56 CST 2007

On Fri, Nov 23, 2007 at 02:33:34AM -0800, satish patel wrote:
> Dear all
>             I have TDM808B 8 port FXO it is configure perfectly 
> but i got some problem of incomming phone Hangup and callerid display 
> problem 
>            i am going to explain you the issue i have install asterisk 
> 1.4 and i have 100 of SIP phone now everything is fine but problem is 
> when i incoming call on FXO and dial sip extention SIP phone is rining 
> but when i disconnect my incoming phon from mobile ( i hangup my cell 
> phone ) still my sip phone rining not  disconnect notification reached 
> to my sip phone so what is the problem 

The FXO can't really know that the remote FXS (your PSTN provider) has
hung up (because the FXO - the phone) is the one that decides if the
circuit is open or closed (if the phone is onhook or offhook).

So you need either to get a hint from your PSTN provider that the call
has ended or (in the worst case) try to guess that from the busy tone.

As for hints: Asterisk (and your card) supports two common ways for
that: polarity reversal (for that: set handuponpolarityswitch=yes [*])

A different method, also used in various places, is power denial. But I
figure that detecting it is already enabled on your system ("ks" as
opposed to "ls" signalling).

[*] Hint for those who cannot memorize this strange name:
strings /usr/lib/modules/chan_zap.so | grep polarity

Being more specific about which PSTN provider it is may help.

               Tzafrir Cohen
icq#16849755              jabber:tzafrir.cohen at xorcom.com
+972-50-7952406           mailto:tzafrir.cohen at xorcom.com
http://www.xorcom.com  iax:guest at local.xorcom.com/tzafrir

More information about the asterisk-users mailing list