[asterisk-users] Got event 17 (Polarity Reversal)...

[Gordon Henderson]

On Sat, 11 Oct 2008, Jorge Mendoza wrote:

> I founded this behaviour in the past. When the CO provides reversal
> polarity and the FXO port is configured to ignore polarity events, then
> a reversal polarity could be detected as ringing if the
> hardware/software is not well designed or configured.
> So, if the CO provides polarity reversal, why not set answer and release
> supervision to yes?

We need the flexability to answer either way...

Here in the UK the (BT) exchange will do a polarity reversal to signal 
incoming CLI - it then send the CLI, *then* sends the ring signals, so 
answering on polarity reversal would be wrong.

They also do a random polarity reversal most nights too - some sort of 
automated line testing. Eg. from my home box:

Oct  7 01:40:28 NOTICE[15581] chan_zap.c: Got event 17 (Polarity Reversal)...
Oct  9 03:53:06 NOTICE[19904] chan_zap.c: Got event 17 (Polarity Reversal)...

Note the times...

Gordon

>
> Jorge Mendoza
>
>
> Jim Duda wrote:
>> If by default Asterisk ignores all polarity events, then why
>> does it cause the Dialplan to start?
>>
>> I did set answeronplarityswitch to no, however, I have had
>> the problem occur once already, so, you suspicion might
>> be correct.
>>
>> Jim
>>
>> Tzafrir Cohen wrote:
>>
>>> On Fri, Oct 10, 2008 at 05:51:29PM -0400, Jim Duda wrote:
>>>
>>>> Tzafrir,
>>>>
>>>> Thanks for the tip.  I'm researching answeronpoliaryswitch.  I suspect
>>>> this will solve my issue.  I never would have know to look for this.
>>>>
>>>> Thanks much!  You made my day :-)
>>>>
>>> Hmm... I might have misled you. By default Asterisk ignores all polarity
>>> events. Using the polarity events can be a useful feature, but I suspect
>>> that it is not the cause of your original problem.
>>>
>>>
>>
>>
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>
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