Boost your NAS’s throughput with link aggregation

YOU’LL NEED THIS LACP-CAPABLE NAS Look for two Ethernet ports on the back. SMART SWITCH This needs to support LACP, too.

DOES YOUR NAS DRIVE come with two Gigabit Ethernet ports? When plugged into a compatible switch, the two ports enable you to combine the two connections using technology called “link aggregation” or “port trunking.” Link aggregation is a catch-all term for various methods of providing a parallel network connection through multiple Ethernet ports. One basic use is to provide a layer of redundancy—if one port fails, the other can still be used. But a more exciting— and practical—use for link aggregation is LACP (Link Aggregation Control Protocol).

LACP increases the throughput of your NAS drive, which means you can speed up the shoveling of data to and from the drive. Hurrah, you cry: double the transfer speed! Sadly, no. You can’t increase the speed of a single network connection using LACP, but you can increase the available bandwidth for multiple connections. This helps when two or more users attempt to access the drive at once—for example, uploading and downloading files at the same time, or attempting to run two movie streams simultaneously, which is why it’s often referred to as “load balancing.” Read on to discover what equipment you need, how to configure it, and how to test your tweaks. 1 CHOOSE THE RIGHT DRIVE If your NAS drive [ Image A] has twin Ethernet ports, check its manual or specs to see what forms of link aggregation it supports. Most drives should offer LACP support, although the terminology varies between manufacturers: QNAP and Synology drives refer to “802.3ad dynamic,” for example. If your drive doesn’t support LACP, check to see whether it provides its own proprietary form of load balancing—see the “Wot, No Link Aggregation?” box on the right for details.

If you’re in the market for a LACP-compatible drive, look for a higher-end SOHO or small business model—QNAP’s TS-231+ is around $170 diskless, for example. 2 BUY THE RIGHT SWITCH Most home routers don’t come with link aggregation support on board. The most cost-effective way to add link aggregation support to your home network is through a managed switch [ Image B]. It’s important that you carefully check the link aggregation features offered by your chosen switch, because cheaper models may not have all the features you need (as we’ve discovered to our cost). For example, TP-Link’s TL-SG108 model costs under $30, but doesn’t support LACP. Instead, you need to shell out $69 for the next model up, TP-Link’s SGT2008, which we’re using as the focus of this tutorial. If you’re using a different model, you need to adapt the steps according to your switch’s instructions.

3 BENCHMARK THE DRIVE Take a rough and ready “before” benchmark by copying a large multi-gigabyte file, such as a drive image, to or from the NAS. Make a note of the transfer speed. Now repeat the process using two separate PCs or Macs, and you should find the transfer speed is roughly halved on each device, illustrating the current bottleneck.

4 IDENTIFY IP ADDRESS AND LOG ON TO SWITCH First, verify that your NAS’s Ethernet cables don’t need to be plugged into specific ports for link aggregation support (any ports can be used on the TLSG 2008, so we’ve plugged our NAS into ports 7 and 8, the two closest to the power switch).

Smart switches are managed one of two ways: either through a third-party utility, or (in the case of TP-Link’s TL-SG2008 model) through your web browser. Type its IP address into your web browser, then log on using the required credentials (if you haven’t previously logged on to the switch, use the manufacturer defaults, then change them for security reasons). If you’re struggling to identify your switch’s IP address, use a tool such as Fing ( www.fing.io) to locate it.