SPA3K doesn't detect my building's lobby phone

[robo]

I've got the Sipura unit almost setup exactly the way I want. I can make and take calls from my analog handset, make and take calls from my computer (via Asterisk), and call from the analog handset to my computer (and vice versa).

However, I have one problem; I live in a condominium high rise and in the lobby of my building, there is a building directory with a handset to dial a number to gain access to the building; for guests, deliveries... but most importantly, pizza ;-).

Anyway, these calls never ring through. I know that they don't because they never show up in my log files (whereas all my other calls do).

Has anyone you seen this problem before and if so, can you provide me with a solution? (And by the way I am not blocking anonymous callers on the Sipura.)

Thanks in advance for your help!

[mberlant]

Please describe your environment a little better, including just how your lobby phone is provisioned. What country are you in?

Can we assume that you have this lobby phone system connected to the FXO port of your SPA-3000? Does this line handle any other traffic, like your POTS phone? Some systems are designed simply to dial your POTS phone from the lobby, while others are designed to be connected to individual telephones in each apartment. What kind is yours?

[robo]

Originally Posted by mberlant

Please describe your environment a little better, including just how your lobby phone is provisioned.

I'm not sure how exactly it is provisioned, but I get the impression that it somehow grabs the line and sends it's own ringing. In fact, the ring from this lobby phone is different (distinctive) than my PSTN calls.

Originally Posted by mberlant

What country are you in?

Canada.

Originally Posted by mberlant

Can we assume that you have this lobby phone system connected to the FXO port of your SPA-3000?

The FXO is connected to the PSTN which the lobby phone also rings through on.

Originally Posted by mberlant

Does this line handle any other traffic, like your POTS phone?

Yes.

Originally Posted by mberlant

Some systems are designed simply to dial your POTS phone from the lobby, while others are designed to be connected to individual telephones in each apartment. What kind is yours?

I'm guessing it is the latter.

Is this possibly related to a lower ringing voltage (this purely speculation on my part)?


Thanks so much again for your time and attention!

[robo]

Well, I've tried adjusting the ring voltage downward to 60 volts with no change. :-(

Does anybody have even a guess as to what I should try?

[Jackson]

Most apartment intercom system uses some kind of a basic ring generator circuit to ring the PSTN phone in individual units, hence there is no call info associated with the ringing signal. If Asterisk cannot process such call, then you are probably out of luck.

[robo]

Point of clarification, the PSTN line (which is what the lobby phone also uses), is plugged into a Sipura SPA-3000, not Asterisk.

Isn't ringing all the same from a device detecting it perspective?

[toddvelie]

OK - Here's a bunch of random thoughts that occured to me... hopefully something will point you in a good direction. :-)

How long does the lobby call ring your phone? Is it something where it just rings when the user is pushing a button, or is it like a real call, where the ringing goes until someone picks up the phone?

If it's a quick one time thing, then maybe the Sipura is 'waiting' to answer for 5 seconds or so, and the ringing stops, so it never picks it up. If this is the case, setting the answer delay to 0 might fix it.

If the system keeps ringing until someone picks it up though... then that idea's kinda blown.

Have you tried having someone ring from the lobby, then as you *know* the phone is ringing, check the status web page for the SPA? (i.e. Sit on it in a webbrowser, and hit refresh when the line is ringing.) This will let you see if the SPA actually thinks that the line is ringing or not. It'll also let you see the true line voltage.

Another thing to check would be PSTN hangup detection. Perhaps the SPA really is being tricked into picking up the line, but the second it does, it realizes that the 'caller' has hung up, since it's being given a standard dailtone. It might not try to pass the caller to asterisk at that point. Maybe you could futz with how the SPA "see's" the line as hung up to make it less reliable. (i.e. take longer to reject or something.)

[robo]

Thanks for the suggestions, I really would like to get this to work as I am sometimes physically unable to answer the phone, yet if I could provide helpers and friends with a touch tone PIN, I could set up Asterisk to open the door (by sending a DTMF ‘6’ upon receipt of a correct PIN).

Anyway, to answer your question, the line does ring repeatedly until it's answered, although, it does eventually time out after a minute or so.

I'll see if I can get someone to call up from the lobby while I try and capture the specifics from the Sipura status page.

[AbNormal]

I don't have the answer to your question, but let me add a few missing details as to how the "Lobby phone" typically works.

First, there are several manufacturers of these devices (EnterPhone is one example), and they operate similarly. The "EnterPhone" system (substitute your brand here) is connected to "your" phone line such that it sits between "your phone" and the telephone company. It is essentially placed "in series", hardware-wise.

All normal telephone calls therefore, pass through the "EnterPhone" system, as though it were transparent. So far, so good. When someone arrives at your building (or front gate, etc) and initiates a call to your residence or suite, then EnterPhone places a call to your phone, with possibly a distinctive ring. Or, if the line is busy, it activates the "call waiting" tone so that you may temporarily talk to the door. A normal voice call takes place between the front door and called party, and if the person being called wishes to allow the visitor access, presses a single-digit code (like 6) to unlock the door, or open the gate.

The operation is actually quite simple, and the first question is: can someone ring you from the lobby, and can you answer the call and establish voice communications? This is key, and unless and until this sequence can be carried out, the rest is pointless.

If you can successfully talk with someone calling from the lobby, then it is "simply" a matter of getting the Sipura to send the DTMF tones "in-band" (most likely), so that the EnterPhone can respond to your command.

Hope this helps somewhat...

[AbNormal]

I've tried adjusting the ring voltage downward to 60 volts

Just an additional comment, that both Canada and the U.S. specify 90 volts for Ring Voltage, at 20 Hz. I believe Sipura ships with default settings of 60 volts at 25Hz.

You may want to re-check these, too.