why there is a bandwidth limitations in serial ports

[mohammed hashim]

hi all

why there is a bandwidth limitations in serial ports ??

like the highest one is 45 mbps

but Ethernet ports reach 100 GB !!

thanks,

[e.ciollaro]

Dear,

each standard has its own specification about media, connectors and protocols. Depending on the type of media and technologies that ware available when the standard has been defined, a maximum speed has also been defined.  The speed depends on the specific media (copper or optical, twisted pair or coax, cat 5 or cat 6), electrical signals (volts, waveform, clock), distance  between device,.... each protocol defines a maximum speed.  It's true that ethernet protocols have a very high speed but over a copper line they are also limited to 100 meters while other serial protocols, xDSL for example, can transmit up to 20Mbps over copper line over a distance of some kilometre. So speed reduction is often a way to have longer connections.

Bye,

enrico

PS: please rate if useful

[Richard Burts]

Enrico provides a good explanation and I am glad to rate it +5. He correctly makes the point that the serial technologies in general make a trade off achieving much longer distances by accepting slower speeds.

I would also point out that when Ethernet was introduced it also had pretty low speed  (10 meg). Over time there have been numerous efforts to make that technology perform better and now we take that higher speed for granted.

HTH

Rick

[e.ciollaro]

Thx Richard 

I really appreciate your evaluation.

Enrico