I have a strange problem here, but according to
this post it seems to be a known problem.
As my sip provider sipgate.de doesn't allow sip calls to or from other sip providers, i use voxalot as my main sip account and have voxalot registered with sipgate. So my dialplan is simply forwarding all calls to sipgate.de. Everything works fine in almost any cases, incoming as well as outgoing. But in a certain situation it doesn't work:
If I call a a number of another sipgate.de user, and this user is also using voxalot to register, then i get a busy signal. But if I call the same number over PSTN it works perfectly. Also if the user doesn't register over voxatel, but directly registers his device at sipgate.de, it works perfectly. So the problem only occurs, if the path is
my device -> voxalot -> sipgate.de -> voxalot -> his device
pstn -> sipgate -> voxalot -> his device
and
my device -> voxalot -> sipgate.de -> his device
works.
I cannot use the SIP-code to call these people, as sipgate.de doesn't allow calls from outside anymore. I also have no way to find out the voxalot number of the user to call him directly. So my only possibility in these cases (if I identify it as such a problem at all) is to call the person over PSTN and ask him for his voxatel number.
Any suggestions? Is this problem being worked on?
Thanks and cheers,
Sven