[Asterisk-Users] Freak incidents, who's to blame?

[Ryan Courtnage]

On 3-May-05, at 10:34 AM, Eric Wieling aka ManxPower wrote:

> Ryan Courtnage wrote:
>
>> Hello all,
>> Everyone has probably experienced this at some point in the past:
>> You pick up your analog phone.  Rather than hearing dialtone, you  
>> are  connected with someone who has just called you.  Neither you  
>> nor them  heard a ring.
>> Maybe it's just me, but it seems these "freak incidents" would  
>> occur  more frequently years ago, than now.
>> I've now experienced this a couple of times with an * system  
>> (TDM400p  - quad FXO):
>> A SIP exten dials digits which are answered by a Zap trunk.  As  
>> soon  as Zap answers, the SIP extension is connected with an  
>> inbound (PSTN)  caller (who was expecting to hear an IVR).
>> My questions are:  Who's to blame (telco, tdm card, * config,   
>> gremlins)?  Is this avoidable?
>>
>
> It's called "glare".

Thank you, I'm now walking down the right path.

 From what I've read, glare is common in 2-way loopstart (kewlstart)  
circuits, and is impossible(?) to eliminate completely.  But now I'm  
wondering what Nortel would tell a customer who experiences glare on  
their new Meridian system... they must do something to prevent glare  
from happening.  Any ideas?

Ryan