How can I solve problems with the router?

The errors listed below can usually be rectified by simply adjusting the configuration in the router:

The call can only be heard in one direction.
Your VoIP end device does not register or loses its registration after a while.
The called party continues to ring even though you have already hung up.
You cannot be reached from outside.
You can dial a number but do not hear any ringing.
The call acceptance is not transmitted to the caller.
The call is disconnected after a while.

 

What does a NAT router actually do?

A router is used when there is only one Internet access, but this is to be made available for several devices or computers in the local network.

The NAT router thus serves as a distributor for Internet access which independently establishes the Internet connection to your Internet provider. It receives a globally unique IP address (according to the scheme 123.123.123.123) from the Internet provider so that it can also send requested data to the router individually. The router in turn makes the Internet connection available to all devices connected to it in the local network (LAN).

To ensure that each VoIP end device that you have connected to the router can also be addressed individually, each of these end devices automatically receives an internal IP address from the router.

Which data is being transmitted?

Your router must know that sipgate will send and receive both voice data and data for establishing a connection. These two types of information always come to your router via the same route:

Voice data is transmitted via UDP over the so-called RTP port.
Switching data is transmitted via UDP via the SIP port.

Both the RTP port and the SIP port can usually be defined in the end device settings.
Please refer to the supplied manufacturer's manual for more information on where exactly you can set the SIP or RTP port.

Where do I enter the necessary data?

The router needs to know to which device this data must be sent. To do this, you need to know the local IP address of your VoIP end device (e.g. 192.168.1.12).

Some devices have a display on which the IP address can be shown (further information on the status of the IP address can be found in the manufacturer's manual).
Softphones (e.g. Phonerlite) always use the IP address of the computer on which they are used.
Your router can also be helpful: In the router's configuration screen, you will often receive a corresponding list of currently assigned local IP addresses via a status page.

Once you have determined the IP address, make a note of it for the next step.

Change to TCP, TLS, and IPV6

In some cases, it may be helpful to switch the phone's SIP communication to TCP or TLS. Switching to IPv6 can also be helpful.

Example Configuration for VoIP-Devices

Many VoIP end devices use a STUN server to establish a connection to our server even with a router with a firewall/NAT. Unfortunately, this does not work properly with every router model. To avoid the problem, please delete the STUN entry. You can find out where you can deactivate the STUN server in your telephone in our configuration help.

 

If you use several VoIP end devices in a network, you will find various instructions on how to set them up individually in our configuration help.

Any reliable, publicly available STUN Server may be used with sipgate services.
sipgate's STUN Server is: stun.sipgate.net
STUN Server port: 3478

What is STUN?

The STUN Protocol, or Session Traversal Utilities for NAT, can assist devices behind a NAT firewall or router with routing UDP packets.

Router related problems can lead to a wide range of issues, including one-way or lost audio, no dial or ring tones, intermittent loss of registration, and problems making or receiving calls.

For most customers, it's normally enough to know that STUN can solve many NAT router related problems, but isn't designed to be a solution in every situation.

Note: It is always worth trying/testing your devices with STUN both enabled and disabled and seeing which of the two produces the best results. Sometimes you may need to omit STUN to see improvements, or, or the other side, sometimes have it active, to see any improvements.   

How to use STUN

Instead of changing the router's settings to resolve issues, sometimes it may be easier and quicker to first look in your phone's settings and try any or all of the following:

  • The use of different Local UDP Ports in your phone's settings;
  • Enable your phone's STUN Server
  • Power your phone and router off and on

Where can I find my phone's STUN settings?

Have you checked your phone's manual or the manufacturer's website?
We've pictorial set up guides for many popular VoIP phones and devices in our Help Centre.
In the settings menus of most phones you'll only need to enter the STUN Server. Otherwise there will usually be separate STUN Server and Port fields. With some phones you'll need to use a special format: stun.sipgate.net:3478 (or stun.sipgate.net:10000)
Older SIP VoIP phones, devices and applications may not support STUN.

Further Information

The STUN Protocol is defined in RFC 5389
http://www.voip-info.org/wiki/view/STUN

My Problems still exist

Check the current software (firmware) of the router. Most router manufacturers constantly update the firmware of their devices. You can usually download these free of charge from the manufacturer's website.

You will find instructions for updating the firmware in the manufacturer's manual. If necessary, the port sharing must be set up again after updating the firmware. Alternatively, check the FAQ instructions on the manufacturer's website or contact the manufacturer's support team.


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