How can I troubleshoot router problems?
How to fix router issues
If you’re experiencing issues, your router may be the culprit. While internet calls usually work without problems, router-related issues can often be resolved with minimal effort. This guide provides simple steps to address common problems.
The following issues can typically be fixed by adjusting your router's configuration:
- Calls are only audible in one direction.
- Your VoIP device fails to register or loses its registration intermittently.
- The phone keeps ringing for the called party even after you’ve hung up.
- You’re unreachable from external callers.
- You can dial a number but don’t hear a ringtone.
- Call acceptance is not transmitted to the caller.
- Calls drop after a certain period.
Some of these problems may not occur immediately but can arise after some time, especially in networks with multiple routers and/or several VoIP/SIP phones.
What does a NAT Router do?
A router allows multiple devices in a local network to share a single internet connection. A NAT router acts as a distributor, establishing a connection to your internet provider and receiving a unique global IP address (e.g., 123.123.123.123). This address ensures the provider can send requested data to your router. The router then provides internet access to all connected devices in the local network (LAN).
Each VoIP device connected to the router is assigned a unique internal IP address by the router, ensuring it can receive targeted communication.
What data is transmitted?
Your router must recognize that sipgate transmits both voice and signaling data. These two types of information follow the same path to your router:
- Voice data is transmitted via UDP over the RTP port.
- Signaling data is transmitted via UDP over the SIP port.
Both the RTP and SIP ports can typically be defined in the settings of your VoIP device. For detailed instructions on configuring these ports, refer to your device's user manual.
Where should the data be sent?
The router needs to know which device should receive the data. To configure this, you need the local IP address of your VoIP device (e.g., 192.168.1.12).
- Some devices display the IP address on their screen (check the user manual for more details).
- Softphones (e.g., PhonerLite) use the IP address of the computer they run on.
- Your router can also provide this information: Many routers display a list of currently assigned local IP addresses on their status page.
Once you’ve located the IP address, note it down for the next step.
Switching to TCP, TLS, or IPv6
In some cases, switching the phone's SIP communication to TCP or TLS can resolve issues. Similarly, transitioning to IPv6 might help.
For detailed information, consult the following resources:
- How to configure signal encryption via TLS
- How to configure my VoIP phone with sipgate
- sipgate’s IP and port ranges
Example configuration for VoIP devices
Many VoIP devices use a STUN server to connect to our server through a router with NAT/firewall settings. However, not all router models support this setup properly. To avoid issues, disable the STUN server in your phone’s settings. Instructions for disabling the STUN server can be found in our configuration guide.
If your router includes a SIP ALG service, disable it as well.
For networks with multiple VoIP devices, refer to our configuration guides for specific tips on setting them up individually.
Still experiencing issues?
Check if your router’s firmware is up-to-date. Most manufacturers regularly release firmware updates, which can be downloaded for free from their websites.
Refer to your router’s manual for instructions on how to update the firmware. After updating, you may need to reconfigure port forwarding. Alternatively, check the manufacturer’s FAQ section or contact their support team for assistance.