Router Requirements with VoIP

By Gene Teglovic
Updated: February 14, 2011

Adding Voice over Internet Protocol (VoIP) to a network requires careful planning. Since voice packets will be now integrated with data packets, adjustments may be needed. Network features such as data bandwidth, voice quality, capacity planning, and router selection/configuration should be carefully examined, and corresponding changes need to be scheduled and implemented. While many network components are likely to be affected, this article focuses on VoIP routers, with emphasis on Quality of Service (QoS).

Traditional routers can handle VoIP calls if VoIP phones are used in the network. A VoIP router performs the same functions as a regular router, with the additional feature of a built-in Analog Telephone Adapter (ATA), which allows analog phones to plug into the network. The ATA is also available as a separate device, which can be placed between the analog phones and traditional routers.

The most important requirement of a VoIP router (as well as the network as a whole) when adding VoIP services is QoS, which is a blanket term that describes measuring and improving VoIP conversations. QoS deals with guaranteeing that packet traffic for VoIP calls is not slowed or dropped by other interfering traffic. Slowing and dropping of packets results in latency, jitter, packet loss and bursting, which all degrade the quality of voice conversations. Call degradation results in delays, echoing, dropped calls, static, and other unpleasant conversational experiences.

Most VoIP service providers negotiate a Service Level Agreement (SLA) with customers to address QoS specifics end to end, such as less than one percent packet loss or 150 milliseconds maximum latency. Most VoIP phones have buffers built in to compensate for network jitter, and VoIP routers can be somewhat configured to control specific settings related to QoS.

Here are a couple quick tips for configuring a VoIP router to ensure it is doing all it can to contribute to the best possible QoS:

Priority Queuing

Configure the VoIP router(s) for priority queuing (a.k.a. “low latency” queuing) for the voice packets, so they go out ahead of the data packets. This goes for any other routers in the network, such as WAN and POP routers. If this functionality is not available in the routers, set the QoS priority for each device using its MAC address.

Port Forwarding

If the router does not support QoS settings as mentioned above, port forwarding can send packets traveling through specified ports to a specific device (e.g., a VoIP phone). This helps lowers the lag from the router, so that the destination device handles more of the processing. Specify the port numbers, protocol, and MAC addresses.

Note that configuration of the VoIP router is one of many steps needed to successfully configure VoIP into a network. Select the best VoIP router and configure it to optimize QoS as noted above, and this will complete one of the critical steps to optimal VoIP performance.
 

Featured Research
  • How VoIP is Transforming the Healthcare Industry

    The healthcare industry, like many industries, is in the midst of an era of rising costs and an ever increasing pressure to drive down expenses. Now, what if we were to tell you that there was a simple solution to these problems? The answer is VoIP. And to make it sweeter, it allows for your hospital staff to utilize modern mobile devices as resources instead of antiquated phone systems. more

  • [Infographic] 8 Common Pain Points UC Eliminates

    Every company has moments of frustration, it is when these moments become extended periods of inefficiency, or pain points, where we start to see loss in productivity and employee morale. What truly sets a successful business apart from those of its competitors, is how they take these pain points and use them as opportunities to improve upon procedures and systems to eliminate pain points and move beyond what was the status quo. more

  • Go VoIP and Go Green

    You may be looking to switch to VoIP because of the cost benefits that it will bring your company, but did you know that it is also FAR BETTER than traditional phone systems for the environment as well? With environmental impact being at the forefront of both consumer and business minds, it is essential that business decisions are made now based on economic AND ecological impact. more

  • eGuide: Comparing UC Vendors

    Changing your company’s business communications solution is an investment in time and money that will touch everyone in your organization. A successful unified communications (UC) deployment should streamline everyone’s work flow, simplify IT operations and deliver a lowered total cost of operations. Your company deserves nothing less. more

  • Getting More from Your VoIP System

    Too many businesses fall into the trap of setting up their VoIP as a "plug and play" and getting to work. However, we have found that this thinking only leads to businesses failing to get the most out of their VoIP experience. We have put together an in-depth guide that will walk you through 15 easy steps to get more out of your system. more