quick network engineering review question

[Gerald Combs]

Jonathan Hutchins wrote:

> To follow up: while ethernet is great for multiple hosts on a local loop or 
> star topology within a building, it's not designed for long distances.  You 
> can often get away with a run between buildings, but when you start building 
> cross-town links you need a different standard.  That's where other protocols 
> like Frame Relay and "DSL" come in.  This is why you need some sort of 
> "modem" between the cross-town link and your ethernet.

Unless you're using 1000BASE-ZX (100km):

http://wiki.ethereal.com/EthernetHardware

Or Long-Reach Ethernet (5000 ft):

http://www.cisco.com/warp/public/779/servpro/solutions/long_ethernet/

Or GigaMAN (180 mi):

http://www01.sbc.com/Products_Services/Business/ProdInfo_1/1,,1545--4-1-0,00.html


There's nothing inherent in Ethernet that keeps you from carrying frames
over long distances.  Most cable and DSL connections simply bridge
Ethernet frames from the home to the CO or head end, which often
qualifies as cross-town.