A network cable splitter (more accurately, a splitter that appears to split an Ethernet connection; true splitting is not the intent or functionality) allows you to connect two devices using a single Ethernet cable run by utilizing the separate pairs of wires within the cable. It does not magically double your bandwidth or network speed.
Here's a breakdown of how they work, and more importantly, what they don't do:
Understanding Ethernet Cables
Ethernet cables, specifically Cat5e, Cat6, and Cat6a, typically contain eight wires arranged as four twisted pairs. Standard Ethernet connections only use two pairs of these wires (four wires total) for data transmission (10/100BASE-T). Gigabit Ethernet (1000BASE-T) uses all four pairs.
How the Splitter Functions
A "splitter" isn't a true splitter. Instead, it acts as a physical adapter that re-purposes the unused wire pairs (in 10/100BASE-T applications) for a second connection.
- Single Cable, Two Connections (Potentially): The splitter divides the eight wires within the Ethernet cable into two separate sets of four wires each.
- Dedicated Pairs: One set of four wires is dedicated to one Ethernet connection, and the other set is dedicated to the second Ethernet connection.
- Requires Pairs at Both Ends: You need two splitters – one at each end of the Ethernet cable run. At each end, one splitter divides the single cable into two separate Ethernet ports, each utilizing only two pairs of wires.
- Limited Speed (Generally 10/100 Mbps): Because each connection only uses two pairs of wires, these splitters typically limit the connection speed to 10/100 Mbps. Gigabit Ethernet requires all four pairs, so it won't work with a splitter setup like this.
What Splitters Don't Do
- Increase Bandwidth: They do not increase your available bandwidth. You're still limited by the bandwidth of the original Ethernet connection.
- Work with Gigabit Ethernet (Generally): As mentioned, Gigabit Ethernet needs all four wire pairs.
- Function as a Switch: A splitter doesn't manage network traffic or assign IP addresses.
Example Scenario
Imagine you have one Ethernet cable running from your router to a room. You need to connect a computer and a printer to the network in that room, but don't want to run another cable. You could use two splitters:
- Router End: Connect the Ethernet cable coming from the router into a splitter. Connect two short Ethernet cables from the splitter into available ports on the router.
- Room End: Connect the other end of the original Ethernet cable into another splitter. Connect short Ethernet cables from this splitter into your computer and your printer.
Each device will now have a network connection (likely limited to 10/100 Mbps).
Alternatives: Ethernet Switches
A much better, and generally recommended, solution is to use a small Ethernet switch. A switch provides multiple ports, handles network traffic intelligently, and allows for Gigabit Ethernet speeds. They're also relatively inexpensive.
Table Summarizing Splitter Functionality
| Feature | Description |
|---|---|
| Functionality | Divides an Ethernet cable's wires to create two separate 10/100 Mbps connections. |
| Bandwidth | Does not increase bandwidth. Limited by the original connection. |
| Gigabit Support | Generally not supported. Requires all four wire pairs. |
| Setup | Requires two splitters – one at each end of the Ethernet cable. |
| Better Alternative | Ethernet switch provides better performance, more features, and support for Gigabit Ethernet. |
| Use Case | When running an additional Ethernet cable is impossible or highly inconvenient, and 10/100 speeds are sufficient. |
Conclusion
Network cable splitters repurpose unused wire pairs within an Ethernet cable to create two separate connections, effectively "splitting" a single cable run. They are not a substitute for a network switch and generally limit speeds to 10/100 Mbps. Their primary use is to avoid running new cable when bandwidth requirements are low and physical limitations exist.
