With a router that uses Ubicom's StreamEngine (see the router's documentation or manufacturer's Web site to see if this describes your router), enabling Automatic Classification allows it to automatically determine which applications should receive network priority without further intervention on your part.
If you're running a VoIP application, for instance, the DIR-655 will automatically assign high priority to protocols such as SIP (Session Initiation Protocol, used in IP telephony signaling) and RTP (Real-time Transport Protocol, used for transporting real-time data such as voice, audio, and video over IP networks), while assigning low priority to file-sharing protocols such as BitTorrent.
These types of routers have another set of QoS features called WISH (Wireless Intelligent Stream Handling). To access this feature in the DIR-655, click Advanced in the horizontal menu bar and WISH in the vertical bar.
The DIR-655 can optimize wireless traffic from PCs running Windows Media Center.
Put a checkmark next Enable WISH to activate it. In the box labeled Priority Classifiers, place checkmarks next to HTTP, Windows Media Center (if you have PCs on your network running Windows versions that include that feature) and Automatic.
With the HTTP classifier enabled, the router will recognize most common file formats for audio and video streams (MP3, AAC, MP4, Flash, etc.) and will automatically assign them a higher priority over other data traffic traveling over your wireless network. By the same token, the Windows Media Center classifier will recognize media traffic flowing from a PC to a media extender, including Microsoft's Xbox 360. With the Automatic classifier enabled, the router will attempt to prioritize other traffic streams that it doesn't otherwise recognize, based on their behavior.
As noted earlier, not all routers offer the same QoS features or take the same approach to shaping network traffic. With the Linksys WRT600N, for instance, you access the router's quality-of-service settings by clicking the Applications and Gaming menu and then the QoS submenu. Once there, you can assign Internet access priority to specific applications or games, to specific devices according to their physical MAC address, to communication protocols and port ranges, or even to the physical Ethernet ports in the router's integrated switch.
Linksys' WRT600N router lets you prioritize traffic by application, protocol, MAC address and even Ethernet port.
Whichever router you happen to own, I hope the information provided here will help you tap whatever QoS capabilities it might have in order to improve your wireless networking experience.
Michael Brown, a freelance journalist living in northern California, has been writing about computers and technology since 1987. He can be reached at brownmdj@gmail.com.