SBC Trunks issuing "Status to UP" event every hour

[Mike Shintani]

We have 28 total phones load balanced across three Fanvil X6U phones configured as SBCs. Today, after no configuration changes to our environment, all three of these trunks starting showing the event below each hour. I do not see any status changed to "down", I only see "Up".

Trunk SBC 'Fanvil X5U-V2 (1000)' (X.X.X.X/10.1.1.69) has changed status to Up

(X masking the actual IP)

How do I determine what is causing all three trunks across these three SBCs to throw a status "UP" change every hour?

Does this mean the trunks are actually going down briefly as well, but that event is not throwing an error?

Was there a change in the Hosted environment that is causing issues with X6U v2 SBCs? We have the most updated firmware (via the 3CX firmware update tool) on all the phones.

 

[SweetAction]

Down is only sent after it being down for 5 minutes. Up is when it changes to up.

If I had to guess, your SBCs/RouterPhones are losing internet connection (all at the same time, which makes sense) for a short period of time. Under 5 minutes, so no down is triggered, but more then a few seconds.

Try setting up a PC with a continuous ping to an internet location. Match the logs from that to the up notifications and I'm guess you will see request timed out at the same time.

 

[Mike Shintani]

Down is only sent after it being down for 5 minutes. Up is when it changes to up.

If I had to guess, your SBCs/RouterPhones are losing internet connection (all at the same time, which makes sense) for a short period of time. Under 5 minutes, so no down is triggered, but more then a few seconds.

Try setting up a PC with a continuous ping to an internet location. Match the logs from that to the up notifications and I'm guess you will see request timed out at the same time.

Thanks so much for this. I’ll certainly setup the ping test. Curious, would you say SIP phone trunks via a router phone (or Fanvil specifically) are sensitive to slight outages between phone and host? Would you expect the phone’s trunk to switch to a down state every time a ping timeout occurred? Say, if I have 100 successful back to back pings but only one drop/timeout in the string, would that trigger the trunk to go down for a single equivalent ping timeout period?

 

[SweetAction]

I don't know that RouterPhones are any more sensitive then any other 3CX SBC. I also don't know the amount of packets lost to be considered down, but I don't think it's just one. Likely its somewhere around 10-15 seconds of no response, but that's just a guess.

 

[SteveITS]

Each hour at the same time? I'd look at something common to them, for instance a cron job/recurring task on the office router, causing a CPU spike.