What does this request from my VoIP Supplier mean?

I am trying to work out what my VoIP provider means in their response to a fault that I have with my VoIP. The fault is that during a VoIP call, either incoming or outgoing, I appear to loose contact with the other party. However have now found that it is a case of I cannot hear them, but they can still hear me and then after about 10/15 seconds theu come back on the line and the call continues. My ATA is a Cisco SPA112 and everything is hardwired. There are two phones on that same VoIP number and both are affected in the same way.

I have been asked, "Have you been able to test this on a Softphone over 4G/data instead of your WIFI/network that normally goes into the handsets?

If not, may I ask of you to please test this since it is highly likely that your network could be causing these audio issues. I would also suggest, you check if SIP ALG is disabled on your router as it is known to cause a lot of audio-related issues on VoIP platforms."

Re SIP ALG, I checked mt Draytek Vigor 2762 and SIP ALG was NOT enabled.

But what do they mean about Softphone over 4G/data instead of your WIFI/network?

I will be asking my VoIP supplier, but they do not turn around queries that quickly (They are NOT Andrews & Arnold)

Thanks.

Cheers!

Edited by Ancient_Mariner (Fri 22-Jan-21 12:35:50)

In reply to a post by Ancient_Mariner:

But what do they mean about Softphone over 4G/data instead of your WIFI/network?

They mean something like this on an Android phone, would test on your home Wi-fi and on 4G to see if you can localise the issue.

Grandstream Wave Lite

Not sure what trying a software option would prove either way, you still have the problem.

My guess is the Draytek might be treating the incoming packets (or additional signalling that is being received whist on the call that the firewall is blocking) as some sort of denial of service attack and so triggers something that blocks all data from the IP for 10 or 15 seconds before allowing it again.

Options to try are: Trying with SIP ALG on, sometimes they do work and can sort out these issues. Also adding some port forwards as instructed at https://www.draytek.co.uk/support/guides/kb-voip-nat... may help. If you have Stun server details set for your VoIP try removing them. If you have IPv6 and your VoIP provider and ATA support it switch to that as it removes all the complexities of NAT traversal.

I'd be very surprised if the problem is with the VoIP supplier, it will most likely be an issue your end.

Hope that helps.

As dect said use an app on your phone,
Another app you can use is called Zoiper.

With DrayTek sometimes you need to telnet on to the router to ensure SIP ALG is disabled.

Thanks
Dan

Thanks dect that makes sense of what they are asking.

I could certainly try that.

Would there be any issue with there being two devices, one my ATA and the other the Softphone being connected to my router at the same time? ie both would ring when my VoIP number called, or should I disconnect the ATA from my router?

My Cisco SPA112 is about 18 months old. This problem only started in December, strangely after I had read farrinaf's VoIP post about call dropping!

I am in the process of swapping my phone from Port 1 to Port 2 on the ATA after setting up that Port for my SIP. How much of the ATA is common to both Ports I don't know, but obviously quite a bit will be.

Cheers!

Thanks for the link to Draytek, I will look into that, especially as it refers to Draytel, who are my VoIP supplier.

I have had issues before with this account. On that occasion incoming calls were often drowned out by a static like noise. Draytel were adament that it was my ATA despite the fact that even voicemail which was a .wav attachment emailed to me if I didn't answer, would often contain the same "static" noise. (That proved to me that it was there problem) After a few months it cleared and never returned.

What will make this fault hard to track down is that it happens at a random time. Anything up to 23 minutes so far, sometime just 3 or 4.

Cheers!

Thanks Dan. Using an App on my phone seems to be the way to go I think.

Cheers!

In reply to a post by Ancient_Mariner:

Would there be any issue with there being two devices, one my ATA and the other the Softphone being connected to my router at the same time? ie both would ring when my VoIP number called, or should I disconnect the ATA from my router?

I personally would temporary disconnect the ATA to simplify things, but you could leave it connected and see what happens.

The thing I don't understand is why it goes 'one way transmission' (e.g. you can't hear them but they can hear you)

At first I was assuming that I was loosing the connecting completely, but then one day the call resumed! Now knowing that whilst I am unable to hear the other party, they can still hear me, I hate to think what I might have been saying just before I hung up!

Cheers!

I had a very similar problem some years ago. I changed VOIP providers, and changed the ATA, but it didn't stop happening until I changed broadband providers (from BT Infinity 2 to Virgin 100). Its been fine since.