Dropped and dead air calls

[CAW1915]

We are currently running 3cx on premise V20, Up-date 6, Build 724. It is a Pro 24 SC license and we have about 70 handsets connected to it. There are no softphones and the client is not using the web client. All calls are going through the handsets. This install is experiencing dropped calls handset to handset as well as inbound and outbound calls. The client makes roughly 800 - 1000 calls a day and they have about a 20% failure rate on the calls. When we look at the log files from both the 3cx server and the SIP provider, the calls are connecting with no issue. It appears that the audio is getting dropped. We are looking for any suggestions as what to do next to resolve the dropped calls.

 

[SteveITS]

Does the firewall check pass? (note it restarts services)

Try enabling the Monitor Connection Quality on an extension or three for a while.

 

[CAW1915]

Thank you for the response. We will try both rerunning the firewall checker and turn on the Monitor Connection Quality on a subset of phones..

 

[CAW1915]

So after running the Firewall Checker and getting a green check (pass), we are still having about a 10 to 20 percent of calls with some type of audio drop. The Monitor Connection Quality shows that there is a "network problem between 3CX" and whatever number the client is attempting to dial. Having said that, this occurs on every external call both inbound and outbound across all of our 3cx installations. Only internal calls (handset to handset or to VM) are marked as excellent. Any advice on what our next steps should be. We are contemplating trying (testing) another Sip Provider.

 

[SteveITS]

Can you packet capture the stream and/or record the call? (and check that audio)
https://www.3cx.com/docs/capture-network-traffic/

 

[CAW1915]

The client has 70+ handsets and makes about 1000 calls a day. It has not been consistent as to which calls will have an issue. Do we capture all calls and wait to hear from the client which one had issues? So far our problem has been we don't find out about dropped calls until the end of the day. Also, I think this would require turning on packet capture for several hours while all phones are in use. From what we've read so far, this might be a bad idea as per the link "Reproduce the issue as quickly as possible, since traffic capture consumes resources and disk space." Any advice on how best to do a packet capture on random dropped audio calls? BTW Thank you for your input. I greatly appreciate your responses.

 

[KyriacosS_3CX]

Indeed packet capture can take up a lot of disk space and some general processing resources if left for too long. Perhaps you can do a short test, capture 5 minutes to see what capture size you have and whether you have the space to do a longer one.

You mention you get "network problem between 3CX..." for basically all external calls. This would in general indicate something wrong with your internet link or with the SIP provider themselves.

See if your ISP or wherever you are getting your internet connection from can do some line metrics for you, such as line saturation etc. Especially if the connection used for SIP traffic with your trunk provider is also used for regular internet traffic it might be that during heavy usage there is simply not enough bandwidth for calls to be done reliably. Could you/they QoS your SIP traffic?

Final suggestion, see if the Trunk provider offers any monitoring features, perhaps that might give some insight. OR they might have servers located nearer to you that you could be using.

Best,
KS.