Firewall Ports need for outside Phone Connection

[WINWARE]

We have several employees that work outside of our company that we would like to setup them up a CISCO 7940 phone for their home office. The phones work perfect in the office, and yes the phone has been converted to use SIP. Does anyone know how to setup these Phones to work in this way? We have a SonicWall as our firewall in the office running the Enhanced OS, and I have opened all UDP Ports stated in the 3CX Console General Settings area. However it just will not work.

 

[Nebula]

Hate to state the obvious but has the default gateway and IP address been changed on the phones? Also what about the firewall settings at the remote end?

 

[WINWARE]

The IP Address and gateway are set by DHCP at the remote location, and as for the firewall at the remote end everything is allowed out. What other setting should be on the remote firewall. The remote end is able to connect to a VOIP Provider, but we would like to disconnect that and replace their service of VOIP with our 3CX solution.

 

[Nebula]

Again I am probably asking the obvious but is the 3CX server/SIP domain set in the phone?

 

[WINWARE]

The phone is configured for the public IP address of the server.

 

[Kevin Attard Compagno]

Hi there

What does the Firewall Checker utility tell you? Do the phones register at all?

Regards

Kevin

 

[WINWARE]

The Firewall checker say everything is OK with a Information (9) status on both the Ports to use for external calls and Firewall Options.

 

[Discovery Technology]

In the SonicWALL you will need to select "support SIP transformations" in the VoIP settings area and make sure that nothing else is selected. This appears to make a big difference on sonicwall firewalls - it is important to leave the remaining settings as default otherwise (I spent a bit of time on the phone with an advanced tech at their support centre one night as it was driving me nuts).

Are you using the UDP 9000 range for your external handsets inbound? Have you tried this via a VPN tunnel to see if there is any difference?

 

[WINWARE]

As for the "Support SIP Transformation" being selected, as am Assuming that is on our internal SonicWall; is that correct?

As for the phones working through a VPN, it works perfect. However, I do not want this to be how these phones work due to not all of our external employees that need these phones have the ability to setup a VPN on a firewall. I need to just be able to configure a phone to work on the outside, send it to our external employee who has high speed internet, and have them to just plug it in.

David Moore

 

[BJReplay]

I know this doesn't answer your question directly, but I've got a bunch of SPA941/2s all working.

Aside from opening the SIP & RTP ports as set up in the general settings (Ports to use for External Calls), I specified the DNS Name of our 3CX server (but you could use IP address) for both Proxy & Outbound Proxy in the SPAs.

For my N82, I also had to specify the Proxy and also the Realm as 3CXPhoneSystem

We have no phones inside our firewall - 3CX is running on a hosted server in a data centre, and we run a distributed virtual office with everyone external.

Hope this helps.

 

[Discovery Technology]

Hi,

I have done this setup a couple of times now and can help.

As long as you setup port forwarding for the STUN server, SIP and RTP (9000 - 9015) to your internal 3CX Server and have enabled "SIP transformations" in the VOIP section on the sonicwall you should be good to go. the enhanced OS also enables you to set the UDP timeout on your SIP traffic so that you don't disconnected between re-registrations of your VOIP trunks.

I have posted some other articles regarding the Cisco 7940 phones in some of the foruams already so I should have that side of the setup covered for you as well.

Let me know if this all works for you.