One of the key reasons I purchased the D-Link DFL-210 SOHO router/firewall was the ability to control the bandwidth allocated between my SunRocket VOIP service and the rest of my network devices. The DFL-210 is a commercial grade router and provides great flexibility, however it is much more complicated to configure than consumer grade routers. I have setup a D-LINK DFL-210 category to capture all my posts related to the operation and configuration of the router.
The theory behind the router and firewall is the state full inspection of inbound and outbound data packets separately. To that end, the firewall requires inbound and outbound rule to enable bi-directional traffic.
I placed my SunRocket InnoMedia MTA-6328-2Re VOIP gateway behind the DFL-210 to provide it more protection and provide my network with capabilities like VPN. However the problem with this configuration is the inability of the VOIP gateway to control the amount of bandwidth it needs to provide high quality voice connections. It is essentially competing with every other device on my network for the available bandwidth and the result can be choppy voice conversations. To remedy the situation the DFL-210 needs to prioritize data packets coming out of and going into the VOIP gateway. D-Link's bandwidth management involves the definition of traffic shaping pipes. These pipes can allocate pre-defined bandwidth segments to specific Internet services and ports.
Here are the steps I followed:
- Configure a static address on the InnoMedia MTA-6328-2Re
- On the DFL-210
- Backup your configuration (just in case)
- Define an IP4 host/network under InterfaceAddresses Objects with the static address you used in the InnoMedia MTA-6328-2Re
- Define a TCP/UDP service under services objects called SIP with a destination port of 5060. This is the standard VOIP control connection (caller id, etc).
- Define a TCP/UDP service under services objects called RTP with a destination port range of 16384-16403. This is the range used by SunRocket for the audio G.711 connection.
- Define a service group under services objects, include SIP and RTP.
- Define an inbound pipe under traffic shaping with the highest precedence set to 120. This is the maximum you will ever need for a G.711 voice connection, 90 might be enough, but I wanted to error on the safe side.
- Define an outbound pipe under traffic shaping with the highest precedence set to 120.
- Define a pipe rule under traffic shaping. Select the service group you defined in 5. The source interface is lan, the source network is the object you defined in 2. The destination interface is any, the destination network is all-nets.
- In the traffic shaping tab select the outbound pipe defined in 7 for the forward chain and the inbound pipe defined in 6 for the return chain. Set the precedence to highest. This provides bi-directional communication.
- Save and Activate the configuration.
So far I am very pleased with the SunRocket service. The majority of my calls have been as good as my land line. This configuration should bring the number of quality calls close to a 100%. The only factor out of my control is Comcast (which has been very good lately) and the Internet...