Sonet in an evolving toolbox

Mar 20, 2002 12:00 PM

With the introduction of new network services like gigabit Ethernet and wavelengths, industry watchers are wondering if Sonet's future is challenged. Concerned network managers worry about their legacy investments and are confused about how these new technologies will integrate into various solutions. With the current economic environment however, it has become clear that digital lines and Sonet will continue to support and integrate with newer technologies to allow for more economical and robust business solutions for geographical expansion and business continuity.

Ode to Sonet

As a point-to-point and ring technology, Sonet services are inherently secure, reliable and fast. These inherent aspects make Sonet useful not only for transferring voice, but also for mission-critical data, including corporate and financial information that must be delivered quickly and securely in a networked environment.

In terms of speed, Sonet can transmit from basic voice to optical speeds of OC-192 (10 Gb/s), with even higher speeds expected in the future. Because of its self-healing ring technology, Sonet services can be restored in less than 50 to 100 milliseconds. Quality-of-service issues are minimized with Sonet--data and voice traffic are groomed before they even hit the Sonet switch. In addition, it is the overhead in Sonet signaling that allows carriers to support operation, administration, maintenance and provisioning (OAM&P) functionality that customers look for in reliable Sonet services.

Digital lines and Sonet services are also relatively easy to set up and configure. Additionally, most network managers are well versed in the technology. This means businesses can easily find employees who are already experienced in network installation, configuration and management. For smaller businesses looking to capitalize on existing resources and needing more bandwidth to grow, this can be a major benefit.

Integrating Sonet for the future

As businesses demand more bandwidth and increased flexibility, digital line and Sonet technology have adapted to integrate with newer technologies such as frame relay, ATM, and IP networking. These services also provide applications service providers and ISPs with secure, dedicated connections from data centers to customers.

Today, carriers and customers are working to integrate Sonet with wavelength division multiplexing (WDM), dense wavelength division multiplexing (DWDM) and gigabit Ethernet. Such integration allows for more network versatility, increased bandwidth and extended reach of a particular protocol to the customer premises.

Frames, cells and packets--Sonet style

Sometimes digital lines and Sonet are seen as competitors to popular frame relay, ATM and IP VPN services. However, these technologies are often used by carriers and customers to work behind the scenes in pushing frames, cells or packets to a destination.

For example, larger enterprises needing to connect regional VPNs to a corporate backbone often look to Sonet for its highly secure bandwidth capabilities in converging traffic toward host ports. ISPs and ASPs have used Sonet because it is technology neutral. These businesses can operate Sonet networks that allow their customers to ride frame relay, ATM or IP over Sonet.

Sonet gives gig-E some backbone

While there has been a lot of talk in the industry about gigabit Ethernet replacing Sonet, it is becoming clear that Sonet will co-exist and complement this technology for both carriers and enterprise customers. The key is to combine gig-E and Sonet to deliver the necessary speed and reliability that many applications require.

For example, enterprises with campus or metro environments benefit from gig-E's efficient and economical LAN-to-LAN connectivity. Many carriers leverage Sonet today to transport gig-E for customers. Many enterprises that have or lease Sonet ring technology already for voice and data traffic can further leverage this technology by riding gig-E over it. By doing this, companies give gig-E a higher quality of service, redundancy and manageability that the protocol itself lacks today.

Riding Sonet over wavelengths

DWDM has been used in service provider core networks for several years now and is beginning to offer reliable protected and unprotected wavelengths through the core and to the customer premises. For example, large enterprises are using wavelength-splitting technology to increase backbone connectivity, speed and efficiency, especially in large ring and campus environments.

Does this mean the end to Sonet? Of course not. While wavelength services are hot right now, only carriers and large enterprises can amass the resources to afford the equipment and requirements of the service today.

Secondly, Sonet is extremely well known, embedded and reliable, making it the "go to" technology for smaller enterprises looking for high-speed private line networking.

Finally, Sonet, at least as a popular voice protocol, is riding over wavelengths offering more efficiency in the network.

Global networking and business continuity

Digital lines and Sonet will continue to be important tools in both carrier and customer network toolboxes in constructing unique network solutions for application needs. As a business continuity solution, digital lines and Sonet's self-healing abilities have served enterprises well in recent natural and man-made events. Many companies use these services as primary networks and as secondary networks for both load balancing and as back ups to their VPNs.

Outside of the United States, private line networking also takes to the sky, via satellite services, to allow for standard and back-up connectivity to remote locations.  Additionally, online bandwidth-on-demand tools allow customers to plan and reconfigure their digital lines and Sonet services to move traffic away from effected locations.

While applications that require increased bandwidth drive the need for newer network solutions, it's important to remember that as newer technologies take the spotlight, mature network technology will not fade away. Rather, digital line and Sonet services will admirably serve alongside other data services to offer a comprehensive range of solutions to address a wide range of business needs.

Chuck Poston is Senior Director of Product Marketing for WorldCom Inc.

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