Can't Hear the caller - New User

Wondering if anyone can help? The problem that I have is that when some one calls in and we pick up the phone, we can't hear them on the other end. But the funny thing is they can hear us. This line is a backup phone for our cells and is not used all the time. This problem only seems to happen when the line isn't used for a day or so. It is almost like the VOIPo line has to be woken up ( just a guessing ). This happens both on the base set phone and the extender phone.




Modem -> hub -> GrandStream -> AT&T wireless phone

This is usually a port forwarding problem, but if you really do mean "hub" and not router, then that would not apply.

Yes, it's a Hub/Switch and the problem happens every 3-4 days.








Modem->Hub->GrandStream->AT&T Dect 6.0 wireless phone/base + extension phone

This is a strange network setup. Do you have other devices attached to this switch other than the GrandStream? If so, how are you correctly "routing" the traffic between the devices? Is the cable/DSL modem a combo unit with a built-in router? If so, then you will need to forward a range of UDP ports to the Grandstream within this unit.

It is hooked up as follows:

Modem->. . . .->Grandstream->AT&T Dect 6.0 wireless phone/base->extension wireless phone
. . . . . . . Hub-
. . . . . . . . . .->Dlink Router->Desktop pc
. . . . . . . . . . . . . . . . . . . .->netbook via wireless signal
. . . . . . . . . . . . . . . . . . . .->Ethernet power line adapter for TV


Sorry thats the best drawing I can do with the pc.

I personally would hook my modem to the router and plug everything else behind it...

Then of course set up your port forwarding on the router to a fixed IP that you program into the ATA(or have VOIPo do so)., and for any other devices you have hooked up as well.

Well, what he has is effectively the same as hooking the Grandstream to the modem directly. The hub/switch just routes Ethernet packets and doesn't know anything about TCP or UDP ports.

I thought that ( if all possible ) that they wanted you to hook the GrandStream in front of the router. I solved this problem by hooking the GrandStream on one leg coming from the hub and the router on another leg.

Please note a hub is not a switch and a switch is not a hub, but i agree...sounds like a port forwarding issue.

I agree with burris: modem ---> router --->devices.

For things to work properly with your current setup, you have to be either be pulling two public IP's from your ISP or pulling two private IP's from your DSL/Cable modem (which may have a built-in router function). Log into vpanel and click the Features tab, then click "Devices". Look under the "Received" and "Contact" columns. If the "Received column is blank and the "Contact" column has a public IP address after the @ symbol, then your Grandstream in not being NAT'd and you have other issues than a port forwarding problem. You will need to open a support ticket. If you see a public IP under the "Received" column and a private IP under the "Contact" column, then you have NAT going on and likely a firewall issue blocking some UDP ports. In this case, you will need to log into your modem and see if you can assign a static IP to your Grandstream and then forward UDP ports 5004-65000 to this IP address.