Hello, hope everything is good.
So recently inherited a customer which has a self-hosted Issabel PBX with about 15 users, really small company.
For the past few days outgoing calls have been dropped at exactly 21 seconds, calls connect and you can hear the person on the other side of the line but at exactly 21 seconds call is dropped.
Fairly new to VOIP in general specially with this PBX, any tip greatly appreciated
Thanks in advance!
It’s worth a shot. Yes.
Often a firewall issue. SIP ALG or a required port not allowing traffic.
this is the answer
Interesting, but why exactly 21 seconds?
This is a known issue. Google it to narrow down further but essentially there is a keepalive that should be sent at around 30 seconds (roughly, depends somewhat on where you start counting). Without this keepalive packet the call will drop as the carrier assumes you left.
It’s been years since I hit this issue. Since you using a bad pbx system I won’t help further than say most have already given you the likely solution but it’s highly likely you need to consider ports, and said keepalive or ack in general.
Here’s people fighting and resolving: https://stackoverflow.com/questions/27614532/sip-call-drop-after-30seconds
Sounds like you have 21 seconds to go
