Monday, July 22, 2013

100 Mbps Business Ethernet vs OC3 SONET Bandwidth

By: John Shepler

Many high tech companies and large corporations got into fiber optic bandwidth service years ago. The service they chose was the one available: OC3 SONET. Since then, many have upgraded to higher speeds, also in the SONET family of service, or simply stuck with the OC3 that has been performing reliably over the years.

Comparing the competing OC3 SONET and 100 Mbps Fast Ethernet.The entrance of 100 Mbps and higher Ethernet MAN and WAN bandwidth is challenging the dominance of SONET fiber service. Long time users are taking a closer look at the competition. Companies upgrading or ordering bandwidth the for first time are doing their homework before choosing one technology over the other.

SONET (Synchronous Optical NETwork) in the SDH (Synchronous Digital Hierarchy) became the core of most metropolitan, wide area and international networks over the last decades. It was originally developed as a massive telephone trunking technology designed to bundle hundreds and thousands of simultaneous phone calls for long distance transport. With the rise of computer to computer communications and the Internet, SONET services were the logical choice to carry data packets as well as voice channels.

What does SONET have going for it? It is a very mature and well supported technology understood by all of the telephone companies and most network carriers. It is highly reliable and can survive certain fiber cuts and equipment failures. There are a number of service levels available between 155 Mbps and 100 Gbps. Costs have also come down over the years to the point where even smaller companies can consider the entry level OC3 SONET service.

Why throw over a winning service for a newer technology like Carrier Ethernet? It comes down to cost, service features and scalability.

In case you haven’t noticed, just about everything that can communicate uses Ethernet. This includes nearly every corporate LAN, all PCs, printers, scanners, routers, network switches and wireless access points. That’s expanding now to telephones, televisions and any other equipment that is joining the “Internet of Things.” Why not an all-Ethernet world?

The brand of Ethernet that leaves your property is called Carrier Ethernet. It has been standardized by and industry group, the Metro Ethernet Forum (MEF), so that it works over long distances, has the operations and maintenance features needed for carrier operations and is compatible from provider to provider.

Let’s compare two very common bandwidth services: 100 Mbps Ethernet vs OC3 SONET. Both are provided over fiber optic strands and delivered to your organization at a specified demarcation point. For Ethernet you use a simple Ethernet copper or fiber patch cord to connect your equipment to the carrier’s demarc. OC3 requires a special interface module that plugs into a router to convert between the Ethernet on your LAN and the SONET that runs on the carrier lines.

This is one reason why SONET is losing ground to Ethernet. If your network and everything on it is running Ethernet, why do a protocol conversion from Ethernet to SONET and back again at the far end just to send Ethernet packets from point to point over to the Internet? There are inefficiencies associated with that conversion process. Plus, you need a specific interface module for each SONET level. An OC3 module won’t work for OC12 or OC48.

SONET has specific service levels, although you can sometimes get fractional or rate limited services below the maximum line speed. Ethernet is scalable by design. The carrier provides an Ethernet port with a maximum speed, typically 100, 1,000 or 10,000 Mbps. Your actual service level can be any speed up to the capacity of the port. You pretty much pay for the bandwidth you are actually using rather than the capability of the circuit.

Scalability can also save you money. A 100 Mbps or Fast Ethernet connection on a 1,000 Mbps Gigabit Ethernet port can be scaled up or down easily. With SONET you start out at 155 Mbps for the entry level OC3. That sounds like 50% more bandwidth and it is. However, many companies really need 50 or 100 Mbps but had to buy 155 Mbps because it was that or nothing. If your 100 Mbps Ethernet connection bogs down, you can call the service provider and ask for an upgrade to 150 or 200 Mbps and have it in a matter of hours or days. If you tap out an OC3 connection, you have to wait days or weeks for an upgrade to the next generally available SONET level of OC12 at 622 Mbps.

Besides being able to order just the bandwidth you need now while knowing that you can easily upgrade when the need arises, Ethernet service tends to be less expensive than SONET on a per Mbps basis. But how about the quality of service? Both can deliver your packets with high reliability, low latency, and rock solid bandwidth. SONET tends to have fewer “flavors” available. It’s usually a protected ring arrangement with symmetrical dedicated bandwidth and five-nines (99.999%) reliability.

With business Ethernet, you need to be aware of what you are ordering. You can now get Carrier Ethernet with the same redundant path protection as SONET to ensure that if one circuit fails, the system will automatically switch to the other path in under 50 mSec. You can also get the same 99.999% reliability, low latency & jitter, and symmetrical dedicated bandwidth that you’ve come to expect with SONET services. However, if your applications aren’t so critical and you are more interested in saving money than in having the ultimate in performance, be aware that you can also order Ethernet services with asymmetrical bandwidth, shared bandwidth and unprotected circuits. These flavors of Ethernet work well for general Internet usage and casual PC backup to the cloud and are considerably cheaper.

Is SONET or Ethernet the best choice for your business bandwidth needs? Get free consulting help from a bandwidth expert who can also get you the best pricing from multiple carriers who offer services for your location. Also get instant online quotes for many bandwidth services up to 1 Gbps.

Click to check pricing and features or get support from a Telarus product specialist.

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