3

I note that USB cable and Ethernet cable (RJ45/Cat5/...) have the same function : to transmit data as fast as possible over a wire or a port that we can connect and disconnect. In their evolution they both try to maximize throughput in bit/second (for exemple 5Gbit/s for USB3 and 10Gbit/s for Giga Ethernet)

Why are the engineering forces splitted between these 2 ways of transmiting data over wires ? Why don't every protocol share the same support and connector type, possibly the one with the best performances ?

Malkio
  • 31
  • 3
  • Because two entirely different engineering teams designed them? RJ45 existed over a decade before USB 1.0. They serve two entirely different functions. USB is designed to transmit power RJ45 is not but might/might not have been adopted to do so. – Ramhound Mar 06 '14 at 17:54
  • @Ramhound I agree that they have different purposes, but [power over ethernet](https://en.wikipedia.org/wiki/Power_over_ethernet) has been around for ages. – nhinkle Mar 06 '14 at 18:15
  • @nhinkle - I thought that was the case. To expand on my comment USB is Universal Serial Bus, it was used to replace serial bus devices, because serial bus devices have horrible transfer rates. – Ramhound Mar 06 '14 at 18:20
  • yes but `power` over Ethernet needs to be supplied power by a switch that is powered itself, when usb gets powered locally from the pc/laptop. – Outdated Computer Tech Mar 06 '14 at 18:21
  • Actually it's 5 G**Bit**/s for USB 3.0 and 10 G**Bit**/s for Ethernet, by the way. Excluding overhead, of course. – Daniel B Mar 06 '14 at 18:34
  • "possibly the one with the best performances" - what do you mean by 'best performance'? Latency, throughput, controller cost... each of those have different trade offs. For example IIRC USB was designed assuming smart host and dumb gadget (so it can be cheap) while Ethernet assumes that all peers are more or less equal. CAT cables are think and long while usb cables are small and can be easily transported. etc. etc. – Maciej Piechotka Dec 05 '17 at 20:40

1 Answers1

1

The answer is backwards compatibility and usage.

Registered Jacks (RJ) was created back in 1976 for telephone and communication use. Telecommunication wiring hasnt changed much over the years. The infrastructure is so ingrained and universal, changing it would be a massive and expensive undertaking.

USB was invented in 1999, specifically for computer peripheral use to unify connectors. Since computers are easily modifiable, connectors can and have easily changed over the years. There are currently 5 standard USB connectors: Typa A, Type B, Mini-B, Micro-A, and Micro-B. There are numerous non-standard USB connectors for devices like phone chargers as well. On top of that, USB 3.1 will introduce a new connector (similar to Apple's Lightning connector.

Is it possible to use one connector? Yes, but there are always limitations, being cost, the laws of physics, and practicality.

Keltari
  • 71,875
  • 26
  • 179
  • 229