Cables, Ports and Data Rates

These tools answer the practical questions that come up around a network. The RJ45 page shows the pin and colour order for T568A and T568B and checks a cable you have already wired. The ports page looks up what runs on a TCP or UDP port number. The data-rate page converts megabits to megabytes and estimates how long a file takes to transfer.

Tools in this group

• Mbps to MB/s Converter — Convert megabits per second to megabytes per second, convert data sizes, and see how long a file takes at your link speed.
• RJ45 Wiring Diagram — Pick T568A or T568B to see the wire color on each RJ45 pin, or enter the colors at both ends to check a cable.
• TCP vs UDP — Compare TCP and UDP, find which one an application or port uses, and see the header overhead of each.
• Well Known Ports — Look up a TCP or UDP port number, a range or a service name and see what the IANA registry assigns to it.