Detecting the Presence of Other Extensions

[olivermsubadra]

Hi,

Without wishing to stray too far into the world of development here ... We're building a softphone that should (like the 3cx mobile client) be able to detect whether or not other extensions are 'online' or not. We have the code to do this, but haven't been able to test it as the requests it sends to subscribe to the presence of our extensions are being rejected (489: Event Package Not Supported). Are there any ports in particular that we need to open/settings we need to change in the PBX in order to get this working?

We're using v15 of the phone system. All other functionality works fine.

Thanks in advance for your advice.

 

[olivermsubadra]

I've been trying to Wireshark the 3cx android client, since the presence feature works fine there, and it seems a logical place to start looking for answers. However, only the registration request/response is shown in the WS log -- nothing presence-related (even though the presence subscription has obviously happened as I can see a list of offline/online extensions). Why so?

 

[leejor]

So, if I understand you correctly, you are trying to duplicate the features of the 3CX softphone insomuch as the Presence feature, is that correct?

As far as I'm aware, and someone at 3CX would have to clarify, that feature is not a standard SIP function, and I assume, could be considered "proprietary", no? Given that the 3CX softphone has changed, from version to version, a number of times, I would expect that this will happen, again, at some point in the future, which may render your efforts obsolete.

If you, or your customers are using the 3CX PBX, why not make use of the 3CX softphones, already developed, for no charge?

 

[olivermsubadra]

Hi leejor,

Yes, that's exactly what we're trying to do.

I'm not sure how presence would be 'proprietary' or unique to 3CX, since the code library we're using has a presence feature (and so do other clients I've looked at). But whether or not it's a standard SIP function, you'd probably know better than me. I suppose that's all I really need to know.

 

[leejor]

To get the definitive answer , you would have to approach the people at 3CX directly. I'm not sure if the Presence feature is, or is not, something that would "translates over" to other SIP soft phones. Are you aware of other SIP(non proprietary) PBX providers that offer a similar feature?