On again, Off again.

[Shox]

Hey gang, got a weird situation. One of my customers can't hear their caller for up to 2 minutes in calls. Intermittent issue, but it's driving me wild trying to figure it out. Tried using UDP, updated the firmware, all that good stuff.

It was happening to them on asterisk, and now it's happening on FusionPBX. Anyone have any ideas on what the issue may be?

 

[whut]

networking issues. I would start by having the customer disable SIP ALG on their router.

Test their domain from your network with your office phones being registered to the domain to prove to yourself and them that it is their networking.

Use TCP instead of UDP since UDP has a very limited header size.

 

[Shox]

networking issues. I would start by having the customer disable SIP ALG on their router.

Test their domain from your network with your office phones being registered to the domain to prove to yourself and them that it is their networking.

Use TCP instead of UDP since UDP has a very limited header size.

I'll give it a whirl, thanks!

 

[pbxgeek]

I've seen an issue like this at the data center end. The sound would disappear. You may want to look into switching your hosting.

 

[bcmike]

If you can run a windows app from the same location (network) as you PBX get ping plotter (I'd suggest paying for the full version it's the best money you'll ever spend) , get the public IP of the problem phone from the registration table. Ask the customer if they can allow ping, and then run ping plotter against it for 24-48 hrs. Over that period you should see where the problem is coming from. If you can't run a windows app from the same network as the PBX, run MTR from the linux command line.

This sounds like a network issue, not a software issue.

 

[Adrian Fretwell]

Be careful about just blindly switching to TCP. SIP was designed to use UDP for good reason, but does specify the need to switch to TCP if packet size becomes a problem.

In this digital age we can so often overlook the simple and obvious. It could simply be a faulty handset cord or earpiece.

 

[bcmike]

Sometimes TCP can be beneficial if you're dealing with a firewall that has aggressive UDP NAT expiry. Other than that, ya keep it UDP.

 

[Shox]

Definitely going to look into that ping plotter. We went with disabling SIP/ALG and that didn't do anything. Funny enough, moving one of the GXP 2130s to a Wi-Fi adapter actually reduced the number of calls with dropped audio. The old GXP2100 we did the same for... not so much. Going back by today to adjust some park preferences and taking a look at the other phone that keeps dropping audio.