QoS / Bandwidth Control

Regular TomsNetworking readers know that I think that Bandwidth control is a very desirable feature to have on SOHO routers. Implemented correctly, it can keep kids (or employees) from sucking up the bulk of your bandwidth for music and video downloads, or any other undesirable activity. So I was looking forward to seeing how this feature checked out in the 9000VPN.

But my enthusiasm quickly cooled once I realized that the 9000VPN's QoS feature allows upstream bandwidth only to be capped to programmable values. This means that it will help if someone on your LAN is running a server that uses up a lot of bandwidth, but it will have no effect for over-active downloaders.

At any rate, bandwidth can be limited by IP address (Figure 8) or Application / Port (Figure 9).

Figure 8: QoS by IP

This implementation is more flexible than the physical port method used by the Draytek Vigor 2900G [reviewed here], but I feel the upstream-only control seriously limits its usefulness.

Figure 9: QoS by Application

I used Qcheck to run a simple throughput test using the IP Grouping settings shown in Figure 8. I confirmed that the bandwidth cap was in effect for the LAN to WAN direction only, and found that a setting of 1000kbps yielded a measured throughput of about 440kbps, less than half the programmed value.

I also was confused by the Priority selector in the IP Grouping section, since the High, Medium and Low Priority settings are used for Application QoS. But OvisLink assured me that the IP Grouping setting would take priority over the Application level setting. If that is the case, I think OvisLink should remove the Priority selectors from the IP Grouping section.