PERFECT SOLUTION --- Solving the router port number is not enough: This adapter Advantage Design: Laptop in three different fixed positions often use back and forth is very problematic, the network cable to lead to one breaking up, this RJ45 1 to 3 way RJ45 Ethernet splitter saves you from having to pull the cable back and forth. POWERFUL FUNCTION --- Use this RJ45 Ethernet Splitter Cable to easily convert one RJ45 connection to two RJ45 sockets. Allows two computers to share high-speed DSL, cable modems and Ethernet ports without the need for a router, by extending an RJ 45 jack to two standard 8P8C designs. HIGH QUALITY --- Built-in driver circuit on 2mm thick PCB board to avoid damage to the conductor leakage. Ensure longer service life. Pure copper plated gold needle (eight cores): more stable transmission, excellent connection and transmission. The fixed RJ45 female interface shields external electromagnetic signal interference to prevent damage to the internet signal. WIDE APPLICATIONS --- This RJ45 1 to 3 RJ45 Ethernet Splitter helps you avoid pulling cables back and forth and to avoid cable breakage. It can also be used as an extension, it is made of high quality materials and has smooth transmission. It can compatible with ADSL, hubs, switch, TV, set-top box, router, wireless device, computer , suitable for Cat5, Cat5e, Cat6, Cat7. WARM TIPS --- This is a high quality product with PCB board inside. But beware, the Ethernet splitter won't create two Ethernet ports from one, which means you can't use two computers at the same time using this splitter. ONE AT A TIME, does not support all computers to simultaneously connect to the Internet.