We have a FreePBX server setup at a client a few months ago. Version 184.108.40.206. Using Voip, no copper lines. They have 5 lines, one of which is to an ATA device for a cordless, though this issue doesn’t pertain to this device specifically.
Off and on, as in one day every few weeks, the client had an issue with their main desk phone, all of which are Grandstream GXP2170 except the cordless, would not answer a call if it rang. This only happens when it rang within the ringgroup for an inbound call. The Ringgroup has all five phones. If the user at the desk couldn’t answer it, they would reach for the cordless, and all would be well, except this would happen multiple times in the day, then fade off the next day and not happen for at least a week or more.
Yesterday the issue seemed to have gotten worse, as the user went between three phones before catching the call on the fourth. The server logs shows no signs of the call being answered/picked up/ignored on the lines that failed. The phones were ringing, so Do Not Disturb isn’t an issue, as far as I can tell. Fail2Ban shown 11 failed attempts in the 15hours of up time, none jailed.
Between the server and the phones is a single POE network smart switch. I’ve seen Fail2Ban on the server for the asterisk-iptables show multiple failed login attempts, none jailed, but not say what they were. Checking the F2B logs doesn’t appear to specifically state it, however I’m not sure if I’m reading them right. I’ve gone as far as shutting own F2B, via Webmin as the terminal command fails to keep it stopped, and has no change.
I’ve changed the ringgroup to using a Queue, with no change. I’m suspecting something with Asterisk, which I can’t find any signs to say one way or the other, same with all the phones.
Basically at this point: A call comes in, all five phones ring, when a phone is picked up, the other phones keep ringing, and the phone that picked up doesn’t answer the call. Not limited to one or two phones.