How to set up Load Balance to aggregate several WAN links together

The Load-Balance routers have more than one WAN port, you can use two or more WAN links to create an enhanced bandwidth output. For example, you have an 8Mbps link and a 12Mbps link, the TP-Link load balance router could help you bind two WAN links, so you can make good use of all bandwidth.

How does Load Balance work?

If you use FTP to download a video, PC will establish only one connection with end-point. If you use P2P software to download, PC will establish more than one connection with end-point. When you have a lot of connections with end-points, Load Balance router can assign these connections to different WAN ports according to router’s policy, in this way all the bandwidths of WAN links are in good use to speed up the whole traffic. That is why Load Balance router can aggregate several WAN links together.

With a load balance router (We use TL-R480T+ as example), one modem, a managed PC, here we go to the detail configuration.

Step 1

Physical connection

Firstly we set up the physical topology, connect the modem to the WAN port of TL-R480T+, then connect your computer to the LAN port, make sure the two links can work properly and have access to the Internet.

Step 2

Configuration of WAN parameters

Configure the WAN port parameters, set modem as bridge mode and establish a stable PPPoE link in TL-R480T+, then we setup Upstream and Downstream bandwidth for this link, note that you should fill in the value truly based on your ADSL bandwidth (You could consult your Internet Service Provider for the bandwidth information). For 8Mbps ADSL link, we set 8192Kbps for downstream bandwidth, the picture below shows it; WAN2 is the same, set up Upstream and Downstream bandwidth according to data that ISP provides. For 12Mbps Dynastic IP link, we set 12288Kbps for downstream bandwidth.

Note: 1Mbps=1024Kbps

Step 3

Enable and measure the effect of Load Balance

In the main menu Advanced àLoad Balance àGeneral. Here you get two choices to set up Load Balance:

Method1

You can unchecked Enable Application Optimized Routing and Enable bandwidth based balance routing, now traffic in router will go through both WAN ports equally. It means router still can aggregate bandwidths. If one line’s bandwidth is much bigger than the other, it is strongly suggested to set up Load Balance according to the next method.

Note: It is not suggested to set Load Balance in this way as you may get trouble accessing bank websites or other HTTPS websites.

How to measure the effect of Load Balance?

After above configuration, we can check the effect of Load Balance.

Method: Test speed in Speedtest^® websites.

Here we take www.speedtest.net as an example. The result shows bandwidths are aggregated:

Method2

Here we check both Enable Application Optimized Routing and Enable bandwidth based balance routing, select all the WAN ports that you want to join the load balance. After this action, the traffic rate of WAN1 and WAN2 would roughly equal to the bandwidth rate of WAN1 and WAN2. So all the bandwidths of WAN lines can be used in a proper way and we suggest you to set Load Balance like this.

How to measure the effect of Load Balance?

Method: Using P2P software to download a hot resource

It is suggested to use P2P software like BitComet, eMule, BitTorrent, to download a hot resource which can establish a lot of connections with end-points. You should select P2P software according to your situation.

Note:

1MB/s=8Mbps.
Due to the measurement principle of www.speedtest.net, it is suggested to use P2P download software for Speedtest^®.

1) Before you enable Load Balance in router, only using WAN1 to download a hot resource first.

WAN 1: Bandwidth 8Mbps(Equals to 1MB/s)

Download speed in ideal conditions: 1MB/s (Equals to 8Mbps)

Download speed in actual conditions: 918.36KB/s

2) Using both WAN1(8Mbps) and WAN2(12Mbps), set up Load Balance correctly in router.

Download speed in ideal conditions: 2.5MB/s (Equals to 20Mbps)

Download speed in actual conditions: 2.08MB/s

Now the download speed is 2.08MB/s which is bigger than 1MB/s, it means the Load Balance takes effect!

You may ask why the actual download speed is less than 2.5MB/s? Actual P2P download speed could be influenced by many factors like real network conditions, the number of connections and so on. In a point, the P2P’s maximum download speed of specify resource is a fixed value. If your bandwidth is less than that, you can get full download speed of your bandwidth, otherwise, you can’t.

For example, connections between PC and end-points can provide 0.5MB/s(4Mbps) download speed, and your bandwidth is 1MB/s(8Mbps), the maximum download speed you can get is 0.5MB/s(4Mbps), not your bandwidth 1MB/s(8Mbps). But if your bandwidth is 0.25MB/s(2Mbps), the maximum download speed you can get is 0.25MB/s and it is equal to your bandwidth.

So actual P2P’s download speed is related to your bandwidth and the maximum download speed. That is why sometimes we can’t get full download speed even if we enable Load Balance in router.