DrayTek routers can automatically prioritise SIP Voice over IP traffic over all other data, with no configuration required once this facility is enabled.
The router checks for SIP Signaling packets used to establish Voice over IP calls and observes how those calls are set up. With this information it will automatically determine the Local IP address of the IP phone, the Remote IP address of the remote caller and the ports used by the RTP (Real Time Protocol) stream to send the voice packets.
It then assigns those sessions to the highest priority “VoIP” queue so that the call audio is prioritised above file downloads and other Internet traffic with no other configuration required:
The router can then display details on the quality of each call that has passed through the router:
- Whether the call is still in progress (Status)
- The Internet connection used to make the call
- The Local IP and Remote (Peer) IP of the call
- Delay, Jitter and Packet Loss information
- Time and Duration of each call
App QoS is an easy way to control the priority of pre-defined traffic types that the router can recognise, for instance DNS and SSH traffic can be prioritised while Peer to Peer traffic is de-prioritised.
This works similarly to the router’s App Enforcement for Content Security Management, which looks for certain packet types or sequences of packets and can block those types of traffic; App QoS sets the priority of these sessions instead:
In the Untraceable tab are some applications that the router can identify, but can not identify every single packet during the connection’s lifetime. For instance, BitTorrent packets and other peer to peer protocols with stateless connections.
The router applies QoS to “Untraceable” applications by identifying the destination IP addresses that the application is using. It applies the Quality of Service classification for all packets headed towards the application’s detected IP addresses. In this example, peer to peer traffic is put into the lowest priority QoS class to allow other Internet traffic such as VoIP and DNS to have priority.
