Review: Comtrend Ethernet Over Coax Adapter Kit (GCA-6000)

One of the big technology revelations for me last year was the blistering network speeds available using coaxial cable and the MoCA 2.0 standard, realised via the Actiontec WCB6200Q Wireless Network Extender & ECB6200 Adapter. Using existing cabling, I’m able to achieve speeds of over 800 Mbps – slower than Gigabit Ethernet, but far faster than Wi-Fi and Powerline.

The standard has been around for a while, offering an alternative solution for network cabling. It promises gigabit speeds and, unlike other standards, supports networking over all existing in-home wiring types: coaxial cable, phone lines and electrical wiring. However, traction to date has been slow – chipsets and devices have taken time to reach the market in any kind of volume and service provider adoption has been minimal.

Comtrend has been leading the way on from a device perspective, with their PG-9172 model, a 1200 Mbps powerline adapter, debuting last year. The standard was given a further boost with the launch of the Arris SURFboard cable modem and RipCurrent range of products that supported These products are built on technology developed by the HomeGrid forum, and compete with a much more dominant array of HomePlug powerline devices. An Anandtech real world comparison of the Comtrend powerline adapter with an assortment of HomePlug AV models from Zyxel, D-Link and NETGEAR showed that offered “a better user experience and has technical advantages over HomePlug” – but, of course, it lacks the same market acceptance and interoperability with the large install base of the latter.

But that’s powerline. Comtrend have now turned their attention to Coax. The Ethernet over Coax Adapter (GCA-6000) is the first standards compliant Ethernet over Coax adapter on the market, extending the range of media available for networking in the home.

The consumer benefits are the same as MoCA 2.0. High speed networking throughout the home without the need to run Ethernet cable – you simply use existing coaxial cables that may have been installed when your house was built for cable TV. But there’s one big catch. If you’re already using those cables with a cable TV/Internet service, you’re not going to be able to use these adapters, unlike MoCA adapters, which happily coexist. The problem is a frequency conflict between the Cable modem (which using DOCSIS) and the network adapter. If you’re using coaxial for satellite TV services, or HPNA over coaxial, you’ll be fine. As you’ve guessed, if your ISP delivers broadband services using MoCA over Coax, over Coax isn’t going to be an option.

Comtrend tells me that the key benefit of Ethernet over Coax, compared to MoCA is faster, real-world network speeds. They say, “ does this by better managing interference which is both common and expected in real world environments. The standard is based on the latest in Forward Error Correction (FEC) technology called LDPC (Low density parity check). Basically, this means that data performance is maximized, given differing levels of interference, using the latest in advanced error correction ensuring that packets are delivered error-free as fast as possible.”

As a result, they outline a view that is a better standard for video transmission – which is may well be from a technical perspective, but with speeds of 800 Mbps+ available via MoCA 2.0, it’s a moot point from a local networking standpoint. It’s more than suffcient for multiple HD/UHD streams.

The street price of the GCA-6000 is $59.99-$69.99 for a single unit and $99.99 for a pair. Let’s take a look at what they can do.


The Comtrend Ethernet over Coaxial Kit ships with two network adapters (one for each end of the network connection), two power adapters, two Ethernet cables and a short installation leaflet. A minimum of two adapters are required for a network connection, supporting up to 32 device connections.

They’ll happily stand on a desktop or floor, or can be wall mounted from the rear (no screws supplied). As usual, construction isn’t the most lavish but they’re compact (3.90 x 2.67 x 0.96 in; 99 x 67.7 x 24.5 mm) and will certainly take a knock.


You’ll notice two coaxial connectors to the left (output/input), with a power input, Gigabit Ethernet port and configuration button on the right – this is used to enable/reset onboard AES 128 Bit Encryption, pair additional devices and, when held, perform a factory reset.


Status LEDs on the top of the device provide network coverage (successful adapter pairing), Ethernet and data encryption status.

Getting Up and Running

The process to install the GCA-6000 kit is much the same as installing MoCA adapters. You connect one adapter to a coaxial outlet near your router and run an Ethernet cable between the two devices. The second adapter is connected to an available coaxial outlet near the device you wish to connect to your network – such as a games console, PC, media receiver and so on. You run a second Ethernet cable between these two devices. You’ll notice that each adapter has two coaxial connectors which, in theory, can be used as a passthrough for a TV signal. However, Comtrend advises that these adapters should not be used in conjunction with Cable TV and Internet services.

As I’m hooked up to cable here, I’ll be testing the kit by simply using a long coaxial cable running between the two adapters.

With the adapters connected, the Ethernet status lights will illuminate and flash green. The Coverage LED, however, will be illuminated green, orange or red, depending on the strength of coaxial connection. As I’m testing the kit with a relatively new coaxial cable (rather than my home coaxial wiring), I’d expect the connection strength to be very good and I was not disappointed.

You can choose to leave the network connection unencrypted, if you wish, but the recommendation is to secure the connection via the Config button. Press the button on the first adapter for three seconds and you’ll be granted two minutes to do the same on the second adapter to complete the security configuration. If successful, you’ll notice that the Security LED, which blinks when the Config button is first pressed, will be illuminated in solid green. While the configuration worked first time, I did find that it took around thirty seconds to complete the process, which is longer than I’ve experienced with Powerline adapters, for example. We’ll see how encryption affects performance, if at all, shortly but overall, getting up and running with these adapters was very straightforward.


For this test, I put the Comtrend GCA-6000 kit up against the trusty Actiontec ECB6200 MoCA 2.0 kit I’m currently using around my home. While these are competing standards (and, depending on your home & ISP configuration, you may not have a choice which to use), it’s a great opportunity to see which is faster.

I used the industry standard application iPerf to measure upstream and downstream speeds between two Intel Core i5 powered PCs, with a TP-LINK AC5300 router providing the routing duties.

The difference in performance between the two adapter kits was stark:


The Actiontec MoCA 2.0 kit delivered speeds in excess of 800 Mbps on both upstream and downstream tests. It blew away the Comtrend adapter kit, which could only muster 344 Mbps upstream and 262 Mbps downstream. These latter speeds are a viable alternative where wireless may be patchy and Powerline may not provide a stable or sufficiently fast connection. 344/262 Mbps (drop 50 Mbps or so for encrypted connections) is fast enough to push multiple HD/UHD streams around a household, so is not to be sniffed at – but the Actiontec MoCA 2.0 kit is in a different class altogether.


While the standard is progressing – albeit very slowly – based on the performance of the Comtrend Coax over adapter kit, I wouldn’t recommend it over MoCA 2.0 at this point. Of course, if your ISP is mandating the use of kit, then Comtrend’s kit provides a convenient solution for extending a wired network without the need to run additional Ethernet cable. Speeds are reasonable, particularly compared to 2.4 GHz wireless and Powerline so the kit will do a decent job for media streaming alongside regular file serving duties.

But at this point, if you have the choice of an Ethernet over Coaxial standard, there’s little here to prevent me recommending MoCA 2.0. Actiontec’s ECB6200 adapters deliver close to Gigabit Ethernet speeds and I’ve found them to be very reliable this year.

Going forward, I’ll look forward to seeing how progresses and hope that increased adoption drives further performance gains from a wider range of device manufacturers. For now though, there’s a way to go.

Leave a Reply