Grandstream HT702 rings only periodically

I have a Grandstream HT702 ATA and it has been great for making outgoing calls but will only ring periodically for incoming SIP calls via flynumber.

Because it rings sometimes I am assuming it is not router/firewall related - I am thinking it is the configuration on the HT702… but not sure which setting.

The PBX Panel sometimes says it is “unreachable” so I am not sure if I need to do something to send a “stay alive” signal or something.

Any ideas?

Thanks - I love the PBX panel by the way - a great easy to use and understand system.

OK for a couple of weeks I have been struggling with this, but the moment I post this, change one setting and I think I have fixed it (for now anyway).

It was a “keep alive” thing I believe.

I spoke too soon. I tried again this morning and it rang, would not pick up and now will not ring at all.

Thanks for the feedback here @MatthewGuy , we appreciate it

Is there a setting or time enabled for the SIP account to expire? Can we test this behavior on x-lite just in case

Perhaps you can take a screenshot of the settings and post it ( with any sensitive removed)

Please also PM or email the username or your FlyNumber as we couldn’t find an account with the discuss email used…


It is often going straight to voicemail rather than ringing the SIP first.

Here is the configuration for the port (It was too big an image to upload):

Or as a pdf (multiple pages) here:

Thanks for the updates and looking this over, will have something shortly.

You can try to set NAT Traversal: Keep Alive and DNS Mode: SRV

This is only a recommendation, it could help to improve the connection, such issues are hard to determine and might not reside with the device configurations, but in the network equipment/configurations.

Also there are some interesting star codes on this device

So for example you may want to use code *79, maybe DND feature was accidentally enabled, preventing you from receiving calls but this would not influence outbound calls.


Thank you for your help. I have changed those settings and I will let you know how I get on.

I really appreciate you taking the time to consider the problems I am having which are on a third party piece of hardware.


Sure thing @MatthewGuy and our pleasure

Let us know if there is anything else we can assist with

Thank you - worked well today - going to try again a couple of times this week to make sure it has been resolved.

You’re very welcome and glad to hear

We appreciate the feedback and let us know if you need anything

This has been working well for the last few weeks - I try to call from work every couple of days to make a test call - and has worked every time.

After a power outage it took an hour or so to properly reset but apart from that I have had no problems at all.

Thank you for your assistance.


Super and very glad to hear this.

Appreciate the feedback here

Our pleasure @MatthewGuy , we appreciate your business

We’ll also be sure to reference this thread in future cases.

Thanks again