Note : This is the classic/original FAQ. For the very latest articles and new content for UK/Ireland users, please visit the Product Knowledgebase here

Using Ethernet 'Rate Control' Restricting Bandwidth via Port Throttling

Note: This article applies to older models such as the Vigor 2900, Vigor 2800 and Vigor 2600 only

By default, all PCs connected to the Vigor's Ethernet ports will have access to the full Internet and peer connectivity speed. This means that the total bandwidth will be shared between all active users. Ethernet Port throttling (Rate Control), available on some Vigor routers allows, you to set a maximum throughput for each of the Ethernet ports P1/2/3/4. Of course, it might not be a single PC on each port - you might uplink to another switch serving a whole department or company, so the throttle level then sets the maximum for that whole segment.

Before looking at rates, it's important to fully understand bit vs. bytes, Kilo vs. Mega etc. as different services are commonly measured in different units and it's easy to get confused.

• 100BaseT Ethernet runs at max 100Mb/s which is 100000 Kbp/s (kilobits per second).
• Your ADSL line is 512Kb/s (or higher). That is Kilobits again.
• Don't confuse Kilobits and KiloBytes

For each Ethernet port on the Vigor, you can set a maximum speed, for sending and receiving data. If your line is 512Kb/s, let's say that we want some ports to be allowed no more than half the ADSL bandwidth. Half of 512 is 256. Our setting for the port must be a multiple of 32, which 256 is, so, by entering 256 into the IN box, the feed to each port (whether a single PC or multiple PCs are connected) will be limited to a maximum Ethernet speed of half of the total ADSL bandwidth.

In our example above, we have done this, apart from for Port4, which has no restriction and will therefore be able to use all of the ADSL and Ethernet bandwidth, when available (but not to the exclusion of others). Where the checkboxes are not checked, the numbers in the fields below them have no effect.

Assuming that there is minimal congestion and contention, a single download will then be received at 256Kb/s instead of the full 512 Kb/s (all figures are approx). Note that Internet Explorer reports the speed as KiloBytes, so it reports 254Kb/s as 25.4 KB/s (note upper case 'B' indicating bytes rather than bits) as shown in the image above.

Note that the rate control setting affects all Ethernet access to the router, including peer to peer traffic which goes via the router's Ethernet ports.

NOTICE : This document is ©2003 and may not be distributed in part or full without specific written consent. Information and products subject to change at any time without notice.