BLF, CAPI and remote users


I have two questions regarding BLF notification with Asterisk…

First, the easiest to explain : is it possible to monitor the two B channels of an ISDN adapter (AVM Fritz configured using chan_capi) ? I would like to see on my SIP phone (SNOM 360) when one or the two B channels are in use…

Second question, a little more complex to explain… here’s the situation :

I have two asterisk on two different locations, connected via IAX2… my SIP phone (SNOM 360) is connected on asterisk Site A, but i would like to monitor also extensions (other sip phones) connected on the Asterisk of the Site B…

I do not want to connect my sip phone directly to the server of site B, too much problems with the security (the two servers are on two DMZ connected via a VPN, my sip phone is not in this DMZ and thus cannot use this VPN).

Is it possible ?

big fat no to both i’m afraid.

It’s probably why i’ve never found the solution :smile:

I had not too much hope for the second question, but the first one is really more disapointing, the ability to see the status of external lines, see when there is incoming call without the need to ring the phone,… is one of the first possibility of a standard PABX :frowning: and in belgium, a company never use pstn lines but allways isdn (cheaper, easiest, multiple numbers, beter quality,…).

But anyway, thanks for your answer, asterisk stay a really great product, just cannot fully replace classic pabx when non-voip lines are used :frowning: at least in europe, i think that ISDN lines are much less used in US.

shared call appearance is regularly covered here, and it’s often requested.

in reality, it’s never really been a problem for me. e.g., a recent install of mine, they wanted to see what lines were available so they could select it then dial. “great” i said, “but that works ok for the 4 lines you have now. do you want to waste an additional 10 buttons/lights on your phone when we add in the SIP trunks ?”. big pause, dawn of realisation, end of problem.

the only person who really needs to see the line status is the operator, and she has FOP on a separate monitor. call parking also replaces the “press hold on this phone, pick it up on that phone”.

From my side, i’m much interested by incoming/outgoing lines than by internal extensions : we are maximum two in the office, i can see when the other is on the phone without using a light on my phone :smile: Thus, i have 12 buttons/lights that i can use for ISDN channels and SIP trunks… it’s for me the only purpose of this lights…

Also : i’m doing support, i like to see how many different lines are still waiting hearing the music when i’m already busy with one time consuming customer :smile:

I will have a look on the possibility to display this kind of info on the screen of my phone (i know i can easily see that on my computer, but i do not like that so much :smile:)…

if you have a phone that supports XML like the Snom or Aastras then this wouldn’t be hard.

in serious call centers i’ve worked “with”, there has often been a big screen with q details and operator stats visible for all to see.

and being able to see 80 FOP buttons in glorious technicolour has got to be better than LCD surely ? :smiley:


I don’t know is this is working with ISDN card but from my side, I’m able to monitor my PSTN line with the hint function. I have 7 PSTN line connected to TDM card. With my Aastra phone, I’m able to see if the ZAP channel (line) is busy but the light isn’t flashing if the line is ringing.

Take a look a the hint function. The phone you use must support BLF. If it’s possible to monitor ZAP channel, I figure out that it’s possible to monitor PRI too.

The difference between pstn (zap channels that i can of course monitor) and isdn is that with a single adaptor, and a single capi driver, isdn can handle two communications (ISDN provide two B channels), and those two channels are not distinct : at the channel level, asterisk only see one CAPI/contr1 , i cannot distinct the two B channels using hint as there is no CAPI/contr1/B1

Which becomes even worse when you have a single card handling 4x E1 connections, for a total of 120 incoming lines on four trunks. :smile: