Need Help GXP 2170


Hello New to the fourm. I need someone to help me. My issue is very complicated for me and home someone can take the time to help me. So I have 2 new GrandStream GXP2170 phones. I have service fusion for my VOIP. So The one phone of my 2 I’ve been trying to get to work I added account to account 1. I got the phone to take calls most of the time sometimes i can try it and works over and over no issues. Then others nothing. I can call out as well most of the time. Also if i can any little setting in the phone on the website for the phone setting it seems to work for a little bit as well. But if I try later it will work then stop again. I am not very tech savy So if anyone can help me this will be great we are switching to full time voip and need help with this ASAP. Here are some specs that may help people who can help me.

My internet is Comcast Bussiness Download is 300MBPS Upload is around 30MBPS The modem model is a Techincolor DPC3941B Docs 3.0
I have one windows computer and 2 macs.
Both are hardwired in from the modem to the phones to the computer.

Hope someone can explain to me and help me out im at my wits end. Thank you everyone.


No more dispersive lines serve, you need details, a scenario and information about FW network infrastructure etc …


I have service fusion and i set my option 6 with the phone number they gave me. and i call it it will ring to the GXP2170. Like i just tried it. But 5 mins ago it wasn’t not rinning or working. On the phone and website, it does show the GREEN status. Like i said it does it sometimes and sometimes it does not it’s not a pattern. I’m not sure about the network infrastructure


Without details and precise scenario is like going to the doctor and simply tell him “I have pain”,
You understand that it’s little to give you a hand

Anyway this is just a user-user forum, the grandstream assistance can be found here:


ok i signed up for this Thank you for the help


The firewall is likely closing the port when there is no activity and/or the response from the provider is not going back to the phone.

Refer to the attached link.

the same applies only instead of connecting to a PBX, you are connecting to a provider (which you can think of as a different PBX).


We had this problem too with Comcast.
If you are using FusionPBX switch your phones to use UDP not TCP for calls. Comcast blocks TCP.

Hope this Helps.


Thank you for everyone for all the help. I’m going to try these steps. So far i did some of the stuff and working so far today. I also have a VPN installed.