General Router Setup and Configuration.
General Overview: Routers are typically the source of network issues related to the implementation of both our SIP trunks and our Cloud Platform.
Most routers do not prioritise VoIP traffic. Further to this, some routers actively disrupt the traffic coming through them, which further inhibits the phones’ abilities to correctly route VoIP traffic. In addition, without prioritization of VoIP traffic on transmission, other devices on the network which use the available bandwidth may cause a drop in call quality. The settings below should be taken as a guide to configuring 3rd party routers. However, we cannot guarantee the success of these 3rd party routers, even when configured to have the settings below.
“Free” routers provided by other ISPs may be either locked down to only their internet service or still accessible by them (meaning they can see everything you use it for). It also means that they can update it at any time, thereby resetting the main settings used to process VoIP packets. It is highly recommended to change it, even if the model number is the same.
General Router and Firewall Settings:
- Disable SIP ALG
- Disable SPI Firewall
- Enable SIP Transformations (specific to Sonicwall)
- Disable Consistent NAT (Specific to Sonicwall)
- White-list our IPv4 addresses (Telephony Users Only – See Here
- Update Firmware to latest recommended version based upon hardware
- Do NOT open port 5060 (or the RTP ports) to any internet-based traffic (i.e. WAN links) unless you are explicitly filtering on the firewall or PBX based upon the public IP addresses of the platform. This is how SIP scanners identify systems to attempt to compromise them!