Incoming Calls Go to Voicemail After Idle Period

[scrooge]

Hello,

I’ve been using Fongo Home Phone for about a week and I think the phone may be going to “sleep” after being idle for a while.

We started noticing missed calls that went straight to voicemail while we were at home --- the phone never rang.

To test this, I left the phone idle for some time and then called it from an external number. The call went directly to voicemail and the home phone did not ring.

Here’s the strange part:

• While in this “sleep” state, all incoming calls go straight to voicemail.

• If I try to make an outgoing call from the home phone, the first attempt fails.

• Immediately after the failed attempt, the phone rings once (almost like a phantom return call).

• I have to pick up the receiver and hang up that phantom call.

• After doing this, the phone “wakes up” and can both receive and make external calls normally again.

Has anyone experienced this before or know what might be causing it?

My setup does involve a router, I have SIP passthrough disabled already.

Thanks in advance.

[Liptonbrisk]

The common cause is a NAT/UDP timeout issue.


1) What brand and model modem are you using?
This would be what Rogers issued you, which is a modem/router combo.

2) What brand and model router are you using?
Something from Asus?

[scrooge]

1) Rogers Xfinity Gateway Modem, I've put it in bridge mode for my router
2) Asus RT-AC86U

[Liptonbrisk]

1) Rogers Xfinity Gateway Modem, I've put it in bridge mode for my router

In the past, I've witnessed bridge mode being reverted after a firmware update was pushed to someone's gateway.
So, I'd check again just in case: https://www.rogers.com/support/internet ... ty-gateway.

2) Asus RT-AC86U

Well, if SIP Passthrough is already disabled, there's not much I can suggest since Asuswrt-Merlin (third party firmware) stopped supporting that model. Merlin firmware allowed adjusting both UDP timeouts. Normally, I would have suggested step 14D. a) from viewtopic.php?p=80377#p80377 if you were using Freephoneline with router firmware that allows adjusting UDP timeouts. However, since Fongo Home Phone uses a locked ATA, I'm not privy to the registration expiry value used nor its keep-alive interval either.

You can find the latest official Asus firmware version here: https://www.asus.com/ca-en/networking-i ... e=RT-AC86U. While it's good practice to keep firmware updates to patch security issues, I am a little doubtful that updating firmware would address this specific problem, but updating might help.

What you've described is consistent with a SIP client (your Grandstream ATA, in this case) losing its inbound connectivity because the NAT mapping or UDP pinhole expired while idle, so inbound INVITEs never make it back to the ATA. Failover, in this case, is sending the call to voicemail instead. NAT keep-alive is specifically intended to prevent inbound calls not ringing and going straight to voicemail by keeping the NAT mapping active. (Inbound calls will go straight to voicemail as well when the ATA is offline or loses registration.)

Because the ATA is locked (you can't change settings), there's not much I can suggest. I feel this needs to be worked out with Fongo Support.

You could try removing the RT-AC86U from your configuration to see whether it's causing the problem, but if you do so, make sure to disable bridge mode first in the Rogers gateway. Otherwise, the ATA and all devices connecting to the Rogers gateway will not be protected by its firewall.

[Liptonbrisk]

While waiting for Fongo to respond after you submit a ticket, I would try this: turn off Rogers gateway, Asus router, and Grandstream ATA. Turn on gateway. Wait for it to be fully up and running first. Turn on Asus router. Wait for router to be fully up and transmitting data before proceeding. Lastly, turn on Grandstream ATA after everything else is up and running. That's always the proper device boot order. The ATA should always be booted last in the chain. 1. Modem (or gateway) first (wait) -->2. Router (wait)-->3. SIP client (ATA).

See if that helps. If that works, it does suggest NAT association issue/corruption developed between the router and the ATA (UDP timeout issue). The keep-alive value in the ATA is important for keeping the NAT association alive, but I don't know what value Fongo Home Phone uses.

You can also test with bridge mode disabled in your Rogers gateway and by removing the RT-AC86U from your setup.

If that doesn't work you will likely have to work out this problem with Fongo support by submitting a ticket.