Optimize your router for VoIP and video
- 10 December, 2010 02:33
We're at an awkward stage as the age of network-streamed multimedia matures. Broadband and cell providers have only recently realized the public's enormous appetite for streaming video, VoIP, and the combination of both.
Most of the home and small-office routers out there are up to the task; unless they're brand new, however, they may not be optimally configured. Fortunately, you can take steps to improve the quality of rich media on your network.
At the end of this article you'll find tweaking specifications for six of the most popular high-end routers. If your model doesn't allow the tweaks we describe on the next page, it may be time to run to the store.
Basic Router Tricks
Routers handle traffic among many devices. If you're not getting the type of performance you want from an application or device such as an IP phone (VoIP), you may need to manage that traffic to make sure there's enough bandwidth for your desired application.
QoS and ports: Contemporary routers manage bandwidth through a technique called Quality of Service. If you're lucky, you'll be able to adjust QoS via the router software simply by selecting a category (such as voice, applications, or gaming) and assigning it a priority (such as highest or normal). This method is by far the least painful, but it isn't always available.
If that method isn't an option, generally you can set the QoS priority for devices by their Media Access Code address -- a string of hexadecimal numbers unique to the device -- as well as by the network name (such as "MyPhone" or "MainPC"), or the IP address (such as 192.168.1.100).
A MAC address is best, as IP addresses assigned by the router's DHCP server may change. Your router may or may not be smart enough to track a device with a changed IP address. A device name is also constant -- assuming that you don't change it yourself. If you want to use an IP address, it should be static, meaning fixed and set on the device, or reserved, meaning set in the router.
Routers perform QoS by analyzing data through packet sniffing and noting which Transmission Control Protocol/User Datagram Protocol ports the data travels through. They then give priority to the types of traffic you specify.
What is a port? You can think of a port as something like an extension number on a landline phone system. Similar to the way a call arrives at a main phone number, data arrives at your router via your broadband connection's IP address. And in the same way a phone call is forwarded to an extension assigned to someone in the company, data is forwarded to the port assigned to a particular protocol or application. You can find a complete list of official port numbers at the home of the Internet Assigned Numbers Authority. Alternatively, check the documentation on the device or application.
Many applications dynamically assign ports according to need. For these you might want to use a network traffic sniffer, such as Microsoft's free Network Monitor 3.4.
Port forwarding: If your router doesn't support true QoS, you may need to use port forwarding, which sends all traffic traveling through a specific port or ports to a specific device. This technique lowers the lag at the router and lets the destination device handle the processing. Keep in mind that a forwarded port then becomes unavailable to other devices. Generally, you specify the port number, the protocol (TCP, UDP, or both), and then either the IP address, the MAC address, or the name of the device
DMZ: Another way to direct network traffic to your device involves putting it in the DMZ. No, it doesn't ship to North Korea -- it simply moves your device from behind the firewall and out in the open, where it can receive all traffic without interference from the router. This arrangement typically gives the device your broadband IP address -- with all the vulnerability that entails. Such vulnerability is why each router has its own firewall. The DMZ is usually reserved for a server or a PC that you'll use for gaming or for serving Websites, and should be considered a last resort for a VoIP phone or a work PC.
Simultaneous dual-band wireless: Concurrent wireless allows you to perform ad hoc QoS by splitting traffic between the two networks. For instance, you could name your 2.4GHz wireless network "WebData," and your 5GHz wireless network "PhoneVideo." Have users connect to the WebData network for surfing or general network chores, and to PhoneVideo for Skype or to watch HD video.
WME, WMM: Wireless Multimedia Extensions and Wi-Fi MultiMedia are two names for the same 802.11e wireless QoS service. By all means, enable WME or WMM if your router supports it. The setting will help with streaming applications such as voice and video, if the destination wireless device supports it. You may see an option for acknowledgement, which triggers the resending of data on errors; for real-time streaming applications this won't help.
WISH: Wireless Intelligent Stream Handling is similar to WMM in effect. It's less prevalent but has specific optimizations for Windows Media Center and Windows Media Center Extenders. Definitely enable this if you're streaming between WMC and an Xbox or WMC Extender.
Optimizing for VoIP
VoIP is the trickiest application for vendors to offer tweaks for because it's bidirectional, meaning that traffic moves in two directions, and no serious lags can be tolerated for conversation to be successful. On the other hand, it isn't particularly bandwidth-intensive in today's terms, and it can survive a relatively large amount of data loss. That's why it uses UDP (which provides non-guaranteed delivery) instead of TCP (which offers error-checking).
Some VoIP phones, like those from Vonage, utilize a router that sits between your broadband modem and your own router. There's nothing really wrong with this setup, and it will assure the best possible call quality, but experienced users will generally place the phone behind their own router and tweak so that they can get better performance for other applications.
If your router is older or does not have QoS settings, you might need to forward several ports or ranges of ports to your VoIP phone. If your router doesn't support port forwarding, get a new router. Many VoIP devices use port 5060-61 (SIPS), but things can vary from there depending on the actual transmission protocol. The specifics should be listed in your user's guide.
Optimizing for HD Video
Although streaming HD video or any multimedia is bandwidth-intensive, you can have it buffered at the endpoint, which can compensate for gaps in delivery. This buffering process, or prefetching of data, is why you'll often see a significant lag between the time you access a video and the time it starts playing.
That said, buffers go dry, and tweaking your router can ensure smooth viewing. Alas, only a few routers have any specifically video-oriented features. Enable WMM to help with wireless video. If you see a video entry in your router's QoS section, put it on the highest setting. If WMM isn't available, use QoS to increase the bandwidth to both the source and destination devices if you encounter problems. Some newer routers will have their own proprietary video-streaming enhancements; enable them.
Next page: How to optimize six popular small-office routers, and when to upgrade
Brand by Brand
Below are brief discussions of how to tweak six of the latest high-end small-office/home-office routers. All function (and are configured) as described on the previous page. Chances are good that the firmware for older and less-expensive models is similar, if not identical.
Beside each router name is its default IP address, username, and password. If the item is expressed in quote marks, type the characters in between. You perform all of the tweaks here in the router's firmware by way of a Web interface, which you can access by browsing to the router's IP address.
2-Wire 2701HGV-B (AT&T)Default IP address: 192.168.1.254Default username: NoneDefault password: Printed on the bottom of the modem
Unfortunately, the 2Wire home broadband modem/routers that are common to so many AT&T DSL and U-verse installations had no general QoS settings at the time of this writing. However, you can forward ports to devices. Under Firewall, Firewall Settings, you'll find a list of applications whose traffic you may forward to a single computer, and you may place a single computer outside of the firewall in the DMZ. To prioritize traffic by protocol, you'll need to put the 2Wire into bridge mode, where it acts strictly as a modem, and let another router handle the QoS.
VoIP settings are limited to the phones that AT&T provides, so you'll have to forward ports to optimize traffic for your IP phone.
Belkin N600 HDDefault IP address: 192.168.1.1Default username and password: None
QoS, located under Play Features, is very easy to use, with general adjustments for voice, online games, video, and general traffic. Port forwarding, referred to as Virtual Servers, is available under the Firewall heading. In the drop-down menu is a long list of applications that saves you from having to look up specific port numbers.
A DMZ is located under the Firewall heading, and the N600 HD offers simultaneous wireless, too. WMM is enabled by default under Wireless, Channel and SSID for both the 2.4GHz and 5GHz networks.
Buffalo NFiniti WZR-HP-G300NHDefault IP address: 192.168.11.1Username and password: Set on first access
Although the NFiniti has a very granular approach to QoS (which you access from the main router page under NAT/QoS), it's dauntingly technical in appearance. You'll see a drop-down list of applications under Services Priority that's lengthy but rather hard to read due to underscores and tilde characters. Fortunately, the help is informative.
It offers no entry for VoIP, so you'll need to set the bandwidth for your IP phone in the MAC Priority box. You can do the same for any device on the network. You'll find a DMZ and port forwarding on other pages under the same NAT/QoS heading.
The G300NH is single-band wireless, but WMM isn't implemented. Buffalo's MovieEngine is in place to prioritize multimedia traffic, however.
Cisco Linksys e3000 High Performance Wireless-N RouterDefault IP address: 192.168.1.1Default username: BlankDefault password: "admin"
For this Cisco Linksys router, QoS is found under Applications & Gaming, then QoS, but is not enabled by default. WMM is enabled by default and on both the 2.4GHz and 5GHz channels, which operate concurrently.
For VoIP, enable Internet Access Priority, select Voice Device from the category drop-down menu, enter a name for the device (this is for ID only, it's not the real device name), and enter its MAC address. The default priority should be high, but if it isn't, set it to that.
You won't find a specific optimization for video, but you can increase the bandwidth to any device and a number of applications -- including Windows Media Player, iTunes, and the like. Port forwarding is also under Applications & Gaming, but you'll get no help with the ports for specific applications, only the basic protocols such as HTTP, SNMP, POP3, and so on.
D-Link DIR-655 Xtreme N Gigabit RouterDefault IP address: 192.168.0.1 Default username: "admin"Default password: Blank
The DIR-655 has more QoS and port-assignment features than you can shake a stick at under the Advanced tab. QoS Engine has an Automatic Classification feature, which is essentially a hands-off QoS; leave this enabled. You can tweak it by setting priority for specific ports. Like Belkin, D-Link refers to port forwarding as Virtual Servers, and port triggering as Application Rules.
For wireless, WMM is enabled by default under Advanced, Advanced Wireless, and a separate configuration page for WISH is available.
Netgear WNDR3700 Dual Band Wireless-N Gigabit RouterDefault IP address: 192.168.1.1Default username: "admin"Default password: "password"
QoS for this router is available in the right-hand pane under QoS setup. It's a bit difficult to navigate, but keep the WMM enabled for both the 2.4GHz and 5GHz bands, and then enable Internet QoS. Click Setup QoS Rule, and you'll see a list of applications, including IP Phone, Google Talk, and Vonage. Set these to Highest, and tweak the rest as necessary.
Under Wireless Settings and Guest Network a/n (5GHz), you'll find a little gem called Enable Video Network, which the company claims will provide smoother video delivery on the 5GHz channels (the unit offers concurrent dual-band wireless). Enable this setting for either network that will be streaming video.
When to Upgrade
You should be able to get just about any device or application to operate correctly using QoS or port forwarding. However, if your router is so old that it can't handle the traffic -- which is most likely to happen with wireless -- then throw in the towel and get a new one.
All of the routers above, except the 2Wire 2701, are top-of-the-line models and offer QoS and gigabit. While gigabit's extra bandwidth isn't strictly necessary for any one task, it does allow for successfully running more concurrent applications, such as talking on your VoIP phone while streaming a HD movie to the living room. All the routers here, aside from the 2701 and the Buffalo NFiniti WZR-HP-G300NH, offer simultaneous (concurrent) 2.4GHz and 5GHz wireless. I'm not necessarily a cutting-edge guy, but in this case, if you're truly serious about streaming multimedia, especially wirelessly, don't skimp.