spa3102 used as voip to pstn gateway issue

[francescoserpe]

hello,

i bought this voip gateway to perform a simple task: use my pc softphone to call using my home analogic line.

so far i managed to perform this, but there is an issue: everytime i send a voipcall to the adapter, the softphone shows the call as immediately connected even if the remote party is not even ringing yet...

how can i fix this? could it be somehow related to the fact that the spa is not correctly regionalized? (i live in italy, the spa was au)

tried modifying parameters here and there but so far the issue is still present.

any idea?

thanks in advance

francesco

[Dan Lukes]

I assume you know you bough EoS/EoL device.

everytime i send a voipcall to the adapter, the softphone shows the call as immediately connected even if the remote party is not even ringing yet

So many possible causes. You didn't described your topology and the call path. So hard to guess anything.

Can you disclose details ? Where/how both parties are connected, who is calling whom - e.g. call path, ...

Attach SPA3102 logs and SIP dialog packets. It will allow us to analyze the issue.

[francescoserpe]

hi, thanks for your reply.

i know that this device is quite outdated, but i used it some years ago and i thought it could perform the required task easly...

about your requests:

i don't know how to get logs from the gateway.. :|

Configuration topology quite simple: my laptop and the spa3102 gw are connected to the same lan (the spa is connected through the wan port), and the spa is also connected to the phoneline through the fxs (line) port...

About sip dialog, i attached the diagram with the exchange of the sip message of a call (call originated from my softphone to the gateway: immediate connect then after some 20 seconds remote party answers and after some seconds it closes the call, which is correctly recognized by the gateway, which closes the call on the voip side too)
below you can find the complete configuration.
thanks for supporting me

regards

[Dan Lukes]

i don't know how to get logs from the gateway.. :|

Follow Debug and syslog Messages from SPA Analog Telephone Adaptors.

But read bottom, it seems no log will not be necessary.

spa is also connected to the phoneline through the fxs (line) port

So the call starts on softphone, then SPA2102 relay it to old gold analog POTS line ? Such kind of line know no signal for "call has been answered". As SPA2102 know no true call state, it can just assume the call is connected.

If you will connect classic analog phone to outgoing line it will not know the call is connected or not either. SPA2102 converts POTS line into SIP, but it can't relay information not available on POTS side.

Analog POTS line know just three signals - seized and unseized (from phone to PBX) and ringing (from PBX to phone).

If you wish to know call state with better precision, you must use protocol suitable to carry such information. E.g. forget analog line, use SIP or so to upstream.

[francescoserpe]

yes i though of this but still the spa is able to detect disconnection from the remote side through the disconnection tone, so i supposed there was some analogic trick allowing to detect connection from the b side...

[Dan Lukes]

While disconnected call is signaled by busy tone, connected call have no specific tone that can be detected. Remember all those automatic messages like "called number doesn't exist" or other early-audio transmission - even if you will be able to detect human speaking, you still can't recognize connected line.

Even you, as human, can't recognize it reliably. I have phone number where we can speak together despite the call will never reach "connected" state. (so you will not be billed, even as caller).

Analog line is just so dumb for the feature you wish for. You need to convert your main phone line to something digital - like ISDN or H.323 or SIP to reliably recognize current call state.

[francescoserpe]

so no solution...

thanks for your replies

regards

[Dan Lukes]

It's short variant of my answer ...

But "fire POTS, use SIP insted" solution is still on the desk.

[francescoserpe]

yes i though of this but still the spa is able to detect disconnection from the remote side through the disconnection tone, so i supposed there was some analogic trick allowing to detect connection from the b side...