[Asterisk-Users] $100 Bounty/Bribe to get E&M Wink working.

Eric Wieling eric at fnords.org
Fri Feb 18 18:27:18 MST 2005


I am offering a $100 bounty (or bribe) (payed via paypal or check, 
your choice) to get this problem fixed before Monday 6am CST.

Rich Adamson wrote:

>>>>>I'm confused. Digium cards do not support E&M trunks, which are older
>>>>>interfaces that include either a two-wire or four-wire audio "plus"
>>>>>two additional wires called the "E" and the "M" leads. So, Wink
>>>>>timing is irrelevant (unless I'm misunderstanding your question).
>>>>
>>>>Uh... my zapata and zaptel.conf exmaple files both show E&M signaling options.  
>>>>I'm no telephony expert but I though that E&M signaling was just buried in the 
>>>>RBS bits like any other CAS T1 signaling.
>>>
>>>
>>>When I responded to Eric's original post, it sounded like he was trying
>>>to interface to an older pbx trunk interface (physical interface).
>>>Those physical E&M interfaces were as described above (each had either
>>>four or six wires).
>>>
>>>What the original post didn't say was the interface to the non-asterisk
>>>pbx was a T1, and one (or more) of the channels were configured for E&M
>>>signaling. Completely different then a physical E&M interface. (Someone
>>>else had asked about a physical interface not more then a couple of
>>>weeks ago, so the mind was oriented along those lines.)
>>
>>The original setup was:
>>
>>CLEC CT1 -> Channel Bank -> (analog) -> Nortel PBX.
>>
>>Current setup is:
>>
>>CLEC CT1 -> Astrisk -> CT1 -> Channel Bank (analog) -> Nortel PBX.
>>
>>The Nortel does not have T-1 interfaces in it and the company is 
>>unwilling to buy a T-1 card for the Nortel.
>>
>>Only 4 channels of the T-1 are E&M Wink (they are for DIDs), the rest 
>>of the channels are various other things.  For the voice channels that 
>>we care about we terminate the channels into Asterisk.  For channels 
>>we don't care about we use the Zappel DACS stuff to just patch the 
>>channels thru.
>>
>>Channels 9 - 12 are the E&M Wink channels.  This is what we see:
>>
>>Failure #1:
>>
>>-- Starting simple switch on 'Zap/9-1'
>>Feb 18 16:13:25 WARNING[1965]: chan_zap.c:4723 ss_thread: getdtmf on 
>>channel 9: Operation now in progress
>>-- Hungup 'Zap/9-1'
>>-- Starting simple switch on 'Zap/10-1'
>>Feb 18 16:13:29 WARNING[1966]: chan_zap.c:4723 ss_thread: getdtmf on 
>>channel 10: Operation now in progress
>>-- Hungup 'Zap/10-1'
>>
>>Failure #2
>>-- Starting simple switch on 'Zap/9-1'
>>Feb 18 16:13:25 WARNING[1965]: chan_zap.c:4723 ss_thread: getdtmf on 
>>channel 9: Operation now in progress
>>-- Hungup 'Zap/9-1'
>>-- Starting simple switch on 'Zap/10-1'
>>-- Executing NoOp("Zap/10-1", "EXTEN=189") in new stack
>>-- Executing Dial("Zap/10-1", "Zap/G3/189||g") in new stack
>>-- Called G3/189
>>
>>In Failure #2 the calls still go thru, as you can see.
>>
>>As you can see when a call suceeds I do not see the getdtmf WARNING 
>>message.
>>
>>We have no problems sending calls to the channel bank, only getting 
>>them from the CLEC.  Since the CLEC used to be directly connected to 
>>the channel bank and then to the Nortel I want to get the wink timings 
>>for the nortel to see if making Asterisk match the Nortel settings 
>>make any difference.
> 
> 
> Since you're really dealing with signaling bits embedded in the T1
> stream, my original comments relative to the physical interface obviously
> don't apply.
> 
> In the old E&M physical interfaces, the E lead represented signaling
> coming from the world (sort of E = everyone) to you, and the M lead
> was you signaling to the world (sort of M = me). The two leads were
> used to solve loop signaling issues, handle answer supervision, dial
> pulse signaling, trunk startup, etc. The audio path was either two-wire
> (eg, pbx interface) or four-wire (eg, LD circuits). I don't recall
> any config options (from my telephony engineering days) relative to
> wink duration, or any other timing adjustments.
> 
> My guess is the asterisk implementation for E&M signaling is probably
> "one" end of that interface, watching the signaling bits and translating
> those into something * can use to terminate the call. However, I'll 
> be the first to admit I'm not a programmer and probably wouldn't 
> recognize the code even if I seen it. Highly unlikely it is a 
> fully-baked E&M emulation, and even higher probability the code can 
> not source an E&M call.
> 
> Do you know if the incoming DID digits are actually dtmf, or is it
> possible the digits are dial pulse on the E lead? (I'd have to guess
> dial pulse from the looks of those messages.)
> 
> Since I have not personally heard of anyone actually using it, I'd have
> to guess that resolving the problem will boil down to writing debug
> code into asterisk, and then writing code that supports your needs.
> Or, change the interface from asterisk to the Nortel to some other
> trunking arrangement.
> 
> Rich




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