Some doubts on 'ethernet'

[Arjun Dabol]

I have some conceptual doubts on ethernet : If any one can clarify , will be a help : i read various sources but few question are un-answered.

1. Does Ethernet only standard to transfer data from 1 system to another system?

2. why we read that ethernet is only for LAN ?

3. Ethernet in other form such as GigaBitEthernet etc ..does work for WAN ?

4. System where we use fiber as medium - also uses ethernet underline - correct ?

5.Don't we use Ethernet for WAN connection ?

6.What else is popular to work over WAN ? is it only POS ?

thanks

Abhishek

[Julio E. Moisa]

Hi Arjun,

I will try my best :-)

1. Does Ethernet only standard to transfer data from 1 system to another system?

Ethernet is a reliable technology to be used between systems but it is a cheap technology compared than other like fiber cables. Fiber or Cat6 is used to interconnect access devices from the LAN room to the Data Center, or to interconnect Data center devices.  Ethernet has a limitation and it is the distance (90 - 100 meters)

2. why we read that ethernet is only for LAN ?

Basically the same answer the the previous question, basically all the computers have NIC with Ethernet ports, now most of the computer have GigaEthernets. The technology is great and it is not expensive, please check this link:

http://www.businessbee.com/resources/news/operations-buzz/buzzbattle-ethernet-vs-fiber-basics/

3. Ethernet in other form such as GigaBitEthernet etc ..does work for WAN ?

Well, at my point of view WAN is a interconnection of many LANs, it dependes if your ISP is providing a network device with Ethernet ports. But behind of these devices are other kind of WAN connections. 

4. System where we use fiber as medium - also uses ethernet underline - correct ?

The most of the devices, yes they support copper (ethernet) or fiber. 

5.Don't we use Ethernet for WAN connection ?

As the question 3, it depends of the device provide by the ISP.

6.What else is popular to work over WAN ? is it only POS ?

There are many type of connections, please check this link:

http://www.comptechdoc.org/independent/networking/cert/netwan.html

Hope it is useful

:-)

[Arjun Dabol]

Thanks a lot. can you please validate my below understanding .

In modern systems :

I See either Copper wire (i think called CAT6 but very less used now a days). Though they can provide speed for ethernet,fast ethernet,gig ethernet like 10GBPS but distance is a concern as they can't go more than 90 m or so..) 

OR

Many people now uses Fiber Cables that can also provide speed of Ethernet/Fast Ethernet and Gig Ethernet (up to 10/40/100 GBPS) and also go a longer distance. hence more popular now a days. ISP uses this mode more now a days.

IN a nutshell...i can also say ...ethernet (10 MBPS,100 MBPS,1GBPS,10 GBPS) can be served using copper or fiber but depends on distance between 2 systems. like if someone need to provide gigabit across under sea...it has to be fiber...

[Julio E. Moisa · Accepted solution]

Hi Arjun,

Yes, that is correct, about 10Gb, also depends of the tecnology, for example 10G-BASE-T twisted pair can support 55m to 100m, depending the CAT used.

Please check this link:

https://en.wikipedia.org/wiki/10_Gigabit_Ethernet

I have seen Data Centers using 10G/40G these capacities are more seen on ISP or Data Centers.

If you are going to provide connectivity for long distances or under the ocean yes fiber should be the solution. Copper is most used for short distances or LANs.

Hope it is useful

:-) 

[Joseph W. Doherty]

1. Does Ethernet only standard to transfer data from 1 system to another system?

No, there are other protocols too.

2. why we read that ethernet is only for LAN ?

Read where?  That's no longer true, although still very popular for LANs.  (If fact, today, for LANs there's really nothing but Ethernet.)

3. Ethernet in other form such as GigaBitEthernet etc ..does work for WAN ?

Sure.

4. System where we use fiber as medium - also uses ethernet underline - correct ?

It can, or it can use other protocols.

5.Don't we use Ethernet for WAN connection ?

No, we don't; i.e. yes we can use Ethernet for WAN (and MAN).

6.What else is popular to work over WAN ? is it only POS ?

Depends where you are and what bandwidths your dealing with.  Many of the WAN technologies were designed to use the hardware that the Telcos used (and still use) before Ethernet.  At the low end, for example, fractional or full T1/E1 (or even DS0).  Next step up, fractional or full T3/E3.  The former also often required a CSU/DSU for media conversion.  Above those you often get into OC#/STM#.  (Once upon a time, 64 Kbps wasn't all that unusual for a lease line WAN connection, and 1.5 Mbps was "high-speed".)

What made today's Ethernet so popular, it was one of the early, of few, LAN technologies that came into wide usage (compared to the other early LAN technologies), and as its usage grew, its cost came down, making it even more popular.  It also "improved" in its later variants, i.e. 10Base2, 10Base5, 10BaseT, then came 100 Mbps and full duplex and/or switched Ethernet.

Today we even have more Ethernet variants, such as the recent 100G, 40G, 25G and mGig.