The Fundamentals Of OC3 Bandwidth...What It Does For Your Business

Written by: Michael Lemm - Nov 20, 2008

When searching for just the right bandwidth solution for critical business network applications a common choice is what's termed an OC3 circuit. An OC3 circuit works as a reliable fiber optic backbone for large networks with substantial voice/data/video traffic needs. For example....corporate headquarters phone lines (PBX and/or VoIP), company Supply Chain Management (SCM) systems, facility high security networks, Hospital medical imagery and diagnostic systems, data recovery and backup networks, video conferencing facilities, multi-media or virtual design centers, and ISP backbones.

OC3 is the abbreviated term for Optical Carrier level 3, and is used to specify the speed level of fiber optic networks over SONET. The speed itself is measured through SONET (Synchronous Optical Network) standards.

Specificly, the Synchronous Optical Network (SONET) includes a set of signal rate multiples for transmitting digital signals on optical fiber. OC stands for Optical Carrier and the number following specifies the speed of the fiber optic networks conforming to the SONET standard. The base rate OC1 is 51.84 Mbps. Therefore an OC3 circuit delivers 155 Mbps.

OC3 is optical carrier (fiber) connected by equipment capable of speeds up to 155.5 Mbps......and is designed to take, synchronize, and transport data and voice at that speed of 155 Mbps reliably. Due to their potential load delivery capacity....OC3 applications are used most often by large enterprises with significant bandwidth requirements or as an ISP backbone. By definition.....an OC3 is the equivalent of 84 T1s or 3 DS3s/T3s. To put it in perspective....an OC3 circuit is capable of 2,000 simultaneous voice transmissions with each transmission carrying variable data types alongside the voice!

An important factor to consider is that OC3s can be burstable, which allows you to start small and increase your bandwidth as your needs grow. A Burstable OC3 is the ideal solution for businesses who seek ultra-fast connectivity for their Internet needs.....and don't require full OC3 load capacity just yet but may in the future. Options cover selection from 60, 70, 80, 90, 100, 120, 140, or a full 155 Mbps of service.

Fiber Optics is a technology that uses glass (or plastic) threads (fibers) to transmit data. A fiber optic cable consists of a bundle of glass threads, each of which is capable of transmitting messages modulated onto light waves.

Fiber optics has several advantages over traditional metal communication lines. They have a much greater bandwidth than metal cables. This means they can carry more data. They are also less susceptible than metal cables to interference, and they are much thinner and lighter than metal wires. This enables the data to be transmitted digitally over fiber optics rather than resorting to analog transmission.

Additionally, OC-3 is most often made up of what is called a "SONET ring" to maintain it's reliability (redundancy) during its high speed transmissions.

A common method of back up used with SONET ring is called a "bi-directional ring topology." This bi-directional ring is a physical topology which deploys two sets of fiber strands.

The first strand for the connection is for sending and receiving. The second strand will reroute traffic from the original transmission in another direction should the first strand break or malfunction. Therefore bi-directional ring topology helps ensure constant reliability within an OC3 SONET based network.

So just what does an OC3 circuit do for your business?

With an OC3 bandwidth solution your network will deliver optimum speed and load for any large scale voice/data application requirement you have....with reliable and secure digital technology performance.