Why you might not want to join two Ethernet cables (and what you should do instead)
The article explains that a simple RJ45 coupler, while convenient for extending a cable, adds an extra physical connection that can become a failure point. Tests by trueCABLE with a Fluke DSX‑8000 showed that three couplers in a run still passed certification, but four caused a failure, indicating that each added joint degrades signal integrity. Moreover, the Ethernet standard caps total copper runs at 328 feet (100 m); joining two 200‑foot cables does not reset this limit, so a coupler cannot magically extend the allowable distance. The piece also notes that a poor‑quality coupler can cause intermittent dropouts, error frames, or force the link down to 100 Mbps from gigabit speeds.
Beyond the immediate technical concerns, the guidance reflects a broader shift toward streamlined home networking setups. Consumers increasingly favor single, well‑rated Cat5e or Cat6 runs for gigabit performance, and the market now offers inexpensive unmanaged switches—often five‑port units for about $15—that eliminate the need for splicing while providing multiple endpoints. These switches create independent links, each respecting the 100‑meter rule, and require only a power source. The article also warns that standard switches lack Power over Ethernet, so devices like security cameras or Wi‑Fi access points may need PoE‑capable switches or injectors, underscoring the growing prevalence of PoE in consumer devices.
Looking ahead, the key risk for DIY network upgrades is relying on cheap or undocumented couplers that may not meet industry standards, potentially leading to network instability that users attribute to ISP issues. As more households adopt higher‑speed standards such as 2.5 GbE or 5 GbE, the tolerance for any additional loss will shrink, making proper cable length planning or switch deployment even more critical. Buyers should monitor emerging low‑cost PoE switches and verify that any cable extensions stay within the 100‑meter limit to avoid future performance bottlenecks.
Key Takeaways
Each RJ45 coupler adds a potential point of failure and can reduce link speed, especially with low‑quality hardware.
trueCABLE’s testing indicates that three couplers may still pass certification, but four typically cause a failure.
A single, appropriately rated cable or a $15 unmanaged switch provides a more reliable solution for extending or splitting a network.
Non‑PoE switches cannot power devices that need Ethernet‑delivered power, so a PoE‑capable switch or injector is required for cameras and access points.
About the Source
This analysis is based on reporting by Engadget. Here is a short excerpt for context:
Joining two Ethernet cables together with a coupler is rare, but when your cords are suddenly too short, there are better options to extend your network.Read the original at Engadget
