The bandwidth of a router refers to many different things. A router’s bandwidth is measured by your connection to the router, the router’s ability to handle and forward requests, and the outbound bandwidth provided to the router. Depending on your router, options available to increase bandwidth include using wired connections when possible, removing optional services such as SPI, and aggregating ports. If your goal is merely to increase network speed, then you need to consider more factors than just the router.
Understanding Bandwidth
Your maximum bandwidth is limited by the slowest part between you and your intended destination. It’s important to understand how bandwidth works with your router. Many routers are integrated deviceswhich include a switch and a wireless antenna. The switch enables you to wire multiple device to a single router, manifesting itself as additional "LAN" ports, while the wireless does the same thing without the use of wireless. Your connection to the router has a significant impact on your perceived routerbandwidth. The actual bandwidth include IP-based headers and other overhead which consumes bandwidth but is virtually invisible to your online experience. Increasing your bandwidth usually involves changing how you and others connect to the router. Routers are also limited by your Internet ServiceProvider – no matter how much bandwidth you have to the router, you’ll never access the Internet faster than what’s allowed by your ISP. Transferring a file to another PC on your LAN happens much faster than downloading a file from the Internet.
Adjusting the MTU Size
The most direct way to increase a router’s throughput is to make sure less of its bandwidth is used for overhead. Overhead includes the bits of information attached to every data packet that informs other routers what type of packet it is, where it’s coming from and where it’s going. When sending or receiving a large amount of data, the router breaks the data into packets. The fewer individual packets there are, the less overall bandwidth is wasted on overhead. A more efficient packet is one that uses the Maximum Transmission Unit, or MTU. The MTU tells the router how large a piece of data can be before breaking it into another packet. Modifying the MTU to a larger size only increases your router performance when transferring large files – small transactions are virtually unaffected.
Disabling the Firewall and Other Services
Routers often include services for security, compatibility or ease of use. Each of these functions consumes resources on the router, a resource which could affect its overall throughput. Many routers, for example, include a stateful packet inspection function, or SPI, for security. This is a function that analyzes every packet transmitted through your router to help protect your network from hacking. If you have a separate firewall, disabling SPI increases the bandwidth available to your router. However, it's not recommended to disable this service without having another security measure in place, such as a Firewall. Microsoft Windows includes a software firewall.
Other Tricks
Depending on your router, there are many bandwidth-increasing options. Channel bonding, for example, allows you to make two or more ports act as if they were one, effectively offering double the bandwidth or more. Channel bonding is used by ISPs to offer speeds beyond what a telephone line or single cable channel normally offers. This is also called “link aggregation” by some equipment manufacturers. If you run a wireless “g” router, eliminating compatibility for 802.11b-based devicesspeeds up the connection for all 802.11g-based devices that are connected to your router. This same trick does not apply to 802.11n-based routers, which are backwards compatible with 802.11g devices. When possible, connect via a wired port instead of wireless. Wired ports provide an unshared, 100Mbps or 1000Mbps of bandwidth from your PC to the router. By contrast, the maximum bandwidth of your wireless is shared by every other wireless device. Furthermore, securing your wireless frequency ensures that your wireless bandwidth is shared only with authorized users, and not hogged by neighbors or "snoopers."
