Engadget: Longer Cable or Switch Often Better Than Ethernet Coupler; Upload Speeds Lag Downloads

According to the first guide, moving a desk can leave a previously adequate Ethernet cable too short, and a small RJ45 coupler lets a user connect a second cable without an outlet, setup guide or network certification. Engadget said a quality coupler should not noticeably slow a connection, but it adds another connection to check when the network misbehaves.

A coupler consists of two RJ45 sockets and does not increase signal strength or create a separate Ethernet link, Engadget reported. One well-made coupler can work, but the extra connection is a potential failure point, especially if the adapter is poorly made or gets bumped. A bad join can cause occasional dropouts, transmission errors or a link falling back to 100 Mbps from 1 Gbps, according to the guide. Engadget advised testing a good cable without the coupler before rebooting a router or calling an internet provider.

The guide also noted the standard copper Ethernet channel limit of 328 feet, or 100 meters, including patch cords. Joining two 200-foot cables would exceed that limit, and a coupler does not reset it. Engadget cited trueCABLE tests of Cat6 and Cat6A cables and couplers with a Fluke DSX-8000 cable tester: configurations with three couplers generally passed, though one earned a marginal pass that was technically a failure, while configurations with four couplers failed. The publication said the result is not a universal breaking point because the tests used specific cables and couplers, but it shows why adding more joins than necessary is a bad idea.

For a single PC or console, Engadget suggested starting with one Ethernet cable long enough to reach and leaving slack when routing it around furniture rather than pulling it tight behind a desk. It said a Gigabit connection can typically be achieved with good Cat5e or Cat6 cable, and an expensive Cat8 cable will not fix poor cord routing. When a cable has already been routed to an entertainment center and a TV, console and streaming box need ports, Engadget said a small unmanaged network switch makes more sense. The incoming cable goes to one port and devices to the others; a five-port model leaves four ports available because one connects to the router.

Unlike a coupler, the switch creates separate Ethernet links, each with its own distance limit, according to Engadget. Basic unmanaged five-port Gigabit switches can be bought for around $15 and require no configuration, but they still need power, and a 1 Gbps model will downgrade transfers via faster cable standards. For a security camera or wireless access point, Engadget also noted that a standard non-PoE switch will not supply Power over Ethernet; a PoE-capable switch or injector is needed.

In a second guide, Engadget reported that home internet download speeds are often far higher than upload speeds. It cited Xfinity plans in its area with download tiers of 300 Mbps, 500 Mbps and 1 Gbps that all had the same typical upload speed of 117 Mbps; the upload speed rose to about 293 Mbps only on the 2 Gbps plan. Engadget said the main practical reason is that most people download much more than they upload, through streaming video and music, installing and updating apps, games and system software, and ordinary browsing. Unless users transfer massive files with cloud storage, stream on Twitch or have multiple people on video calls all day, the guide said they probably do not need a fast upload speed.

The publication attributed slow cable uploads to the medium. Cable internet uses coaxial copper lines originally built for one-way cable TV, Engadget reported, so providers must divide limited bandwidth between downloads and uploads. The DOCSIS standard carries internet signals over those lines, and newer versions raise maximum speeds, but ISPs face high costs to install supporting equipment. Fiber internet, which sends light through cable instead of electrical signals through twisted wire, has much greater theoretical bandwidth and typically offers equal upload and download speeds, according to the guide. Engadget also said cable speeds can slow when everyone in an area is online because nodes and bandwidth are shared; fiber lacks that cable limitation and avoids interference and electrical noise, the guide said.

Engadget further noted that companies such as Netflix and Google use content delivery networks to place servers near ISP networks and deliver downloads more efficiently. A viewer in Florida streaming a movie does not have to pull the data from a West Coast server, the guide said; a server about 200 miles away can deliver it faster and with less strain on the ISP than one 3,000 miles away. Uploads have no real equivalent to the same extent, according to Engadget. Uploaded data must travel to its final destination, which may be far away, and the content is often unique, such as backed-up photos or a recorded video, so it does not benefit from the kind of shortcut CDNs provide when many people watch the same movie. The ISP's infrastructure therefore has to do more work to move uploaded data where it needs to go.

Editor's Summary Engadget's Oct. 18 guides say Ethernet couplers can work but add a failure point and should give way to a single longer cable or a network switch when practical. They also say home upload speeds usually lag downloads because most usage is download-heavy and cable networks divide limited bandwidth, while fiber and content delivery networks change the equation.