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While management systems are nothing new for telecommunications networks, they have not been a priority in building optical networks. Now, with the tremendous demands being placed on the optical layer, carriers are searching for element and network management systems that will optimize this evolving portion of their network. 

Finding a system that can sort through today’s complicated tangle of network elements is easier said than done. Finding a system that is based on many years of optical networking management is even tougher.

To complicate matters, many equipment vendors design solutions with little thought given to optimal management. When pitching to a carrier, most will concentrate on the technology and the applications. Any mention of network management is usually an afterthought, with simply an acknowledgement that the functionality exists. Carriers, too, can be guilty of overlooking the importance of network management; they often engage their operations staff after they’ve made their technology choices.

The operations staff then has to fit in the network management component of the network solution. When this occurs, network management problems are inevitable. The cost of integrating a system into an operations environment--as an afterthought--often can be more than the cost of the hardware in the first place. Because different systems assume different network behaviors and are built on non-standard technology infrastructures, integrating the operations support system (OSS) is always difficult, time consuming and costly.

Many carriers have learned the hard way that the OSS should be an integral component when planning any optical network solution. Simply stated, the OSS is central to how an optical network is set up, provisioned and managed. When done properly, an OSS has the capability to span a carrier’s entire operations to seamlessly integrate a multi-vendor, multi-technology network with multiple domains.

The Complications of Evolution

Six years ago, most major carriers were using Sonet predominantly to transport the traffic running on their networks (usually running at rates of OC-3 to OC-48.) As such, only one element management system (EMS) was needed to handle the underlying technology. 

In the last few years, however, carriers have been looking for ways to maximize their overall footprint and leverage their existing infrastructure. Due to the inherent physical constraints of their networks--finite number of central offices and limited fiber in the ground--carriers had to look at alternatives that would enable them to make the best use of their existing physical infrastructure.

And this is when optical networking got complicated. Now, networks that still possess a Sonet infrastructure (no need to decommission this valuable resource) are being supplemented with new technologies like dense wave division multiplexing (DWDM) to maximize the existing physical infrastructure and provide an order of magnitude more capacity.

To complicate matters further, carriers have been migrating from circuit to packet technology to accommodate the types of high-speed data services their customers now demand. Because carriers have been adding new capabilities to their networks to enable IP (and other packet-based) applications, they now must deal with the additional complexity of having at least two separate domains within the same network.

In today’s optical network scenario, bridging the gap between the service and transport layers has become a real struggle for carriers. What they need is an EMS that masks the complexity of the transport and switching technologies; a single system that doesn’t care about the underlying transport technologies. In other words, they need an EMS that simply performs in accordance with efficient provisioning, configuration and monitoring of the optical solution.

Key advantages of a total network management system  The ability to fit in seamlessly with the embedded infrastructure by using standard, open interfaces. The ability to provide a service perspective rather than just a circuit domain perspective.  The ability to “wear many hats” and ride up and down the TMN stack. A strategy that shields the network elements from changes made to the OSS. The ability to manage large and small networks uniformly and efficiently.

More Than a Pipe Dream

In addition to carriers, savvy vendors recognized this need, and have been working on a solution. The many complex and frustrating challenges of managing optical networks can be met in a next-generation OSS known as total network management system (TNMS). A TNMS system possesses both element management and network management capabilities. It also provides critical linkage to service management functions that bridge the gap between different transport technologies, including electrical and optical cross-connects, multiplexers and line equipment (Figure 1).

In addition, TNMS integrates the management of both time division multiplexing (TDM) and DWDM equipment. Moreover, it uses a standards-based common object request broker architecture (CORBA) interface that facilitates the management of multi-vendor environments.

Network management system (NMS) vendors, for example, are able to manage new equipment faster and with less expense, while network element vendors can enjoy the advantage of simplified integration into a carrier’s operation environments. Most importantly, carriers are able to drastically reduce the costs of bringing new equipment into their operations environment.

Key advantages of a total network management system include:

The ability to fit in seamlessly with the embedded infrastructure by using standard, open interfaces. The ultimate goal of the communication industry is to achieve a plug-and-play environment in a multi-vendor network; the CORBA interface is the means to that end. CORBA has gained the support of the industry because it is an open interface with no intellectual property rights, fast and cost-effective to implement, IP-based and future proof.

While north and southbound (and even peer) CORBA interfaces are desired, many network OSS vendors haven’t figured out how to incorporate them into an existing network infrastructure. Without the CORBA interface, network element vendors are forced to adapt their equipment or EMS/NMS to accommodate the management system. Or worse yet, the onus is on the carrier to adapt its operations, methods and procedures to what the vendor offers.

Network management (with CORBA interface) BUSINESS MANAGEMENT LAYER Budgeting Business Planning Inventory Management SERVICE MANAGEMENT LAYER Service Order Booking Subscriber Administration Client Interface NETWORK MANAGEMENT LAYER Configuration of Sections/Paths Network Supervision and Control Section/Path Protection ELEMENT MANAGEMENT LAYER Control and Supervision of Network Elements Configuration of Network Elements Fault Location on NML Source: Optisphere

The optimal scheme is to place an incorporated CORBA interface between the network management layer (NML) and element management layer (EML). This provides a sub-network that is seamlessly integrated into the central NMS (see Table at left)

The ability to provide a service perspective rather than just a circuit domain perspective. The challenge in viewing operations at the service level is to confidently manage the NML and provide enough links into the service management layer (SML). In doing so, carriers can bridge the gap between the circuit and packet sides of any given network by creating a transparent infrastructure that is non-service dependent. This is imperative as the balance of revenue generated by a carrier’s network shifts more heavily from voice to data.

The ability to “wear many hats” and ride up and down the TMN stack. Bridging the gap between the different domains in the network is only part of the equation. The OSS solution also must address the needs of the layers of the TNM stack (element management, network management, service management and business management) for a carrier to successfully manage its entire network.

Ideally, this is accomplished via a system that is minimally an EMS/NMS platform with “hooks” into the service management or business management layers/functions. (Note: It’s a fine line between an OSS product that does just enough to efficiently manage an optical network and one that is a monolith.)

A strategy that shields the network elements from changes made to the OSS. The ideal platform design allows changes to be made on the OSS side rather than on the network element side of the network. When carriers make modifications to the OSS, they would not be required to make subsequent changes to every network element that ultimately would be affected, which is a nightmare for both carriers and vendors.

Adding new network elements, instituting upgrades or adding new feature functionality becomes easy and straightforward. However, the ability to synchronize feature/functionality availability in both the network element and the OSS only comes from an upfront priority in design and development. Unless managed properly, carriers would be unable to take advantage of the features resident in the network element.

The ability to manage large and small networks uniformly and efficiently. When the OSS is built on a modular platform, carriers can easily add more servers to the system in support of additional network elements. By making it an incremental investment, carriers can cost-effectively grow their networks when customer demand is there to support it. Regardless of the size of the OSS platform, carriers should still have, at their disposal, the system’s entire range of performance and functionality.

Carriers have discovered that customers do not care about the underlying technology that enables the services they demand. All they really care about is that the service is turned up when promised and provides the desired capacity....

Time To Put Operations First

Carriers have discovered that customers do not care about the underlying technology that enables the services they demand. All they really care about is that the service is turned up when promised and provides the desired capacity (at the right price, of course). This attitude also is in line with what the carrier really cares about most--generating revenues. To generate revenue, though, means that a carrier must have the tools to match a service to a customer’s needs, to set up the service correctly and to send a bill that is complete and accurate. In today’s evolving world of optical networks, this seemingly simple scenario hasn’t always been possible.

There are numerous network management hurdles that carriers must overcome to efficiently deploy an optical network, provision it and then realize its true revenue-generating potential. This need is fueling industry demand for a full-featured, commercially available, scalable and non-proprietary optical network management solution--a solution where multi-vendor, multi-technology management systems interoperate in an open architecture environment.

Before a system such as TNMS can make a real difference in the ever-evolving world of optical networks, network planners must change their mindset. Carriers must plan their networks from the perspective of how best to use the technology, rather than addressing operations concerns after a technology choice is made.

While no one has a crystal ball to predict the future, a TNMS platform built with CORBA interfaces can keep pace with the growing optical networks of today by providing the tools carriers need to manage complex, multi-vendor, multi-domain environments. Rather than risk creating a collection of boxes that don’t work together, network planners must put the operational needs of their network first to ensure that their networks evolve into efficient, moneymaking machines.
Shahira Raineri is vice president of marketing for Optisphere Networks Inc. She can be reached at shahira.raineri@optisphere.com.

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