Πρόβλημα με voip, δεν υπάρχει ήχος.

[thodoris2004]

Hi guys,

I was holing that you can help me with a problem i have with my SIP phone.

I moved from UK to Greece and registered with COSMOTE. Once i activated the connection and tried to use my SIP phone (software on the computer) i realized that i cannot listen and cannot be heard.

The phone connects fine to the server based in US but for some reason the voice does not work. After some troubleshooting with the support team of my company, we found out the ISP is probably blocking some ports and this is the route cause of the problem.

I have added all the exceptions to the firewall and port forwarding is in place. Could any of you give me some suggestions please?

[kronos911]

Hello
Welcome to Greece. If you are getting you local phone service from Cosmote over VoIP (phone line comes out of the router instead of the wall) then they are reserving port 5060 UDP for their service.

If your US based VSP supports registering on an alternate port other than 5060 UDP you must use that.
Also you might have to forward UDP ports 10000 to 20000 to your PC/Laptop (assign a static dhcp address to that device) running the softphone

[thodoris2004]

Thank you Kronos for the quick response.
The VSP uses port 5060 and i have already forwarded this port along with the range 10000-20000 to my laptop which is configured with a private IP. I even had COSMOTE support double check the port forwarding.
The SIP phone works fine when i connect through a 4G stick so i dont think that port forwarding is the issue here. COSMOTE seems to be blocking some ports needed for the VoIP. Maybe 5060??
My problem with COSMOTE is that they have a difficulty understanding what i am asking for. They even reset the SIP password and now the SIP number is not even registered. I was wondering if you have experienced the same issue?

[kronos911]

Hello
As I stated before, if your local telephone service from Cosmote (voice) is over their VoIP network, (your in house phone is connected to the speedport 2i router and not the wall jack itself) you cannot use port 5060 to register with other VSPs.

Ask your US VSP if they have an alternate registration port other than 5060.

As for you sip service not working try restarting the router so that it can be provisioned again by the auto provisioning system cosmote has in place for there VoIP service.