Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Announcements

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. If you'd prefer to explore, try our test area to get started. And see here for current known issues.

Bronze

Ethernet vs. SDH/SONET

Can someone help me understand what are the benefits of using Ethernet switching in the MAN as opposed to SDH/SONET?

  • Metro
7 REPLIES

Re: Ethernet vs. SDH/SONET

One word - money. Ethernet gear is cheaper to buy and cheaper to run.

So what's the problem? Reliability and availability. The installed base of traditional SONET is huge and SONET technology has been engineered for excellent reliability and fault-tolerance, albeit at a high cost. Ethernet is improving on reliability, but is still lagging. Ethernet is also gaining popularity but its presence in the metro/WAN is still miniscule.

New Member

Re: Ethernet vs. SDH/SONET

Use that link: http://www.cisco.com/offer/tdm_home/infrastructure/man/ethernet.shtml

There are very useful article: "Understanding Ethernet in the Metropolian Area Networks".

Also I was writing another article (only in Russian language yet), where described some troubles for service providers, who implement they access networks on Ethernet technology:

1. Security risks of Spanning Tree.

2. VLAN Management.

3. Choice- Layer 2 or Layer 3 services for customers.

http://www.itc-yar.ru/doc/pub/Efm.pdf

New Member

Re: Ethernet vs. SDH/SONET

Bear in mind that some Service Providers are also providing Ethernet services over their SDH networks. Just to confuse the matter further.

I think the only real benefit in that case is to the end user, ethernet interface on a switch or router is rather a lot cheaper than a POS interface on a router.

New Member

Re: Ethernet vs. SDH/SONET

SONET is inherently channelized, into fixed rates of 1.5, 50, 155 Mbps, etc. SONET is layer one exclusively, switching implies a second layer. In Ethernet or ATM, the channels are virtual allowing oversubscription of a given shared pipe. When the customers traffic patterns are diverse, the packet switched systems can carry alot more customers in a given carriers network, compared to a pure SONET network. Manufacturers have combined the two, allowing shared channels of a SONET distribution network to carry ethernet traffic to multiple 10/100BaseT ports, confusing your equipment choices.

New Member

Re: Ethernet vs. SDH/SONET

I do agree with $$$ aspect as mentioned. If you consider the ML Series in the 15454, a Metro Ethernet solution is very viable. Part of the reason is that the ML has 12 10/100 port or 2 GE ports and allows traffic to be stat muxed around an RPR ring to offer metro services. The stat mux ability allows the customer the ability to get more bang for their buck vs. using a nailed up STS between locations that really only serves that one customer.

New Member

Re: Ethernet vs. SDH/SONET

hi,

GE ethernet is only a layer 2 consideration.

sonet is a physical layer 1 issue

I do think u mess it up

New Member

Re: Ethernet vs. SDH/SONET

It is also an important point to use Etherchanneling over 100/1000 Mbps Ethernet links. This is useful for midrange fiber lines or point-to-point copper links between aggregation devices. This ability extends the useability of F-/G-Ethernet in MAN-environments.

2628
Views
9
Helpful
7
Replies
This widget could not be displayed.