Basic:Metro Ethernet and DWDM vs SONET question

[news2010a]

Hey, my understanding is that in order to deliver Metro Ethernet solutions, one system must be based on DWDM.

SONET, for example, cannot deliver Metro Ethernetsince that is based on TDM (not Ethernet, duhhh).

If the above is right, so I want to confirm that there is no other technology out there besides DWDM which can deliver Metro Ethernet services for enterprise customers?

[Tom Randstrom · Accepted solution]

Metro Ethernet can be delivered over any number of networks... some of them even using Ethernet over SONET.

I would suggest you take a look at the following website for some background on metro Ethernet.

http://metroethernetforum.org/

[Marvin Rhoads]

Any number of underlying technologies can be used to deliver Metro Ethernet services - DWDM, SONET, pure play Ethernet over metro area fiber, etc.

It's more of an economic (what installed base does the carrier have or able to obtain the use of and at what cost) and efficiency (how much of the overall capacity can be feasibly broken into resellable Ethernet services without too much stranded or wasted capacity) question than a technological one. Some technologies lend themselves better to one or the other of those factors thus their dominance in certain markets.

The industry is very adept at achieving previously unthought-of solutions through the introduction of additional layers of abstraction (e., Ethernet over SONET, inverse multiplexing, etc.)

[viyuan700]

SONET was TDM based but not now things have changed. With the help of features like GFP, VCAT(Virtual Concatenation) & LCAS (Link Capacity Adjustment Scheme) it can be used to carry Ethernet etc.

Whatever technology SONET is based on but it is going to be a technology for WAN till the time DWDM become dynamic like SONET.

For shorter distance you can carry Ethernet directly over fiber but once you go beyond that disatnce and you dont need a whole wavelength kind of capacity the you need SONET to carry it.