The topics of declining voice revenues and service providers’ growing need to develop new offerings in order to grow revenues have been exhaustively discussed. It is also clear that due to a rise in competition, companies are now earning less revenue per customer from voice than before. And it is now known that video and data services are entering the picture as potentially new ways to generate revenue for providers. Much has also been written on the need to upgrade one’s network to deploy these services. 

But one question remains. How can a network operator manage this new reality in a cost-effective way?

Operators have several options for tackling the demand for increasing bandwidth and services. They can provide packet-based services over their existing TDM transport network or they can build a new overlay Ethernet network completely separate from the existing transport one. In addition, they can also take an evolutionary path, starting from Ethernet over TDM and migrating to a pure Ethernet network.

Can network operators guarantee their financial stability while simultaneously investing substantial sums of money to satisfy the customer demand for bandwidth?

The not-so-simple answer must account for capital expenses, operational expenses, network resources, and network management. Yes, Ethernet is widely recognized as the most cost-effective infrastructure for next-generation networks, but how and when to carry out the shift remains unknown. However, the key for successfully launching services over Carrier Ethernet networks lies in management systems.

Carrier Ethernet networks encompass different layers: Ethernet, IP, and MPLS with a successfully running management system at the heart of these three technologies working in harmony.

Carrier Ethernet Approach and Management Impact

So, what is the best Carrier Ethernet approach to take? That decision enormously impacts management: if Carrier Ethernet overlays the existing TDM network, then, typically, the management systems would be integrated to some degree. Yet when Carrier Ethernet and TDM networks are isolated, the management systems are usually separate as well. If the latter decision is taken -- to go with separate management systems-- service providers are often forced to invest in high-end operational support systems (OSSs) so that management is ultimately unified.

Creating a new dedicated network management system (NMS) for Carrier Ethernet would make managing packet-centric technology a snap, but the extra costs of integrating a new NMS with an existing one plus an OSS suddenly make this option look far less attractive.

But there is another option: a converged network management system to manage all technologies from a single application. Since this application has to balance management of several diverse types of equipment, network design is simplified and integration costs, implementation and training are all reduced. This type of system would manage alarms, topology information and service provisioning for all technologies in a single database, enabling data correlation from all technologies (Ethernet, SDH/SONET, and DWDM), and would provide added-value functionality, such as cross-technology root-cause analysis for alarms.

Why develop a separate NMS for Carrier Ethernet? The answer lies in the technological differences between Ethernet and SDH/SONET and their traffic engineering concepts. While Ethernet is packet-based using statistical methods, SDH/SONET is based on TDM technology using dedicated circuits. Moreover, some application designers work under the assumption that a different underlying technology requires a separate management application, typically with a different look and feel.

Another reason causing application designers to develop separate NMSs for Ethernet and other transport technologies is that many Carrier Ethernet management systems are based on Enterprise Ethernet management applications. In the enterprise environment, there is no need to manage transport technologies so the unified multi-technology NMS is not a viable option.

Of course, another reason is that developing a new separate NMS for Carrier Ethernet requires less effort than a converged system. In fact, many Carrier Ethernet management systems have been implemented as a separate NMS. While time-to-market is reduced, it’s often at the expense of service providers' TCO. With the growing focus on TCO reduction and system consolidation, many service providers now look for unified management systems instead of separate management systems.

Unified Management

A unified management system reduces CAPEX (including the amount of servers and software applications) as well as OPEX (News - Alert) by enabling more efficient use of staff and reducing maintenance costs. For providers looking to evolve from SDH/SONET over DWDM to Carrier Ethernet over DWDM, a consolidated NMS is a perfect fit. Its SDH/SONET and DWDM capabilities are immediately available and the Carrier Ethernet capabilities can be simultaneously activated, according to market pace.

Consequently, the same person can manage all technologies and a user of a consolidated NMS can quickly switch from one technology to another, removing the need to invest in upper-level OSS in order to provide a unified management system. But if NMS and OSS integration is, in fact, required, a unified NMS makes the integration easier, since only one single northbound interface is needed for integration with upper-level management systems.

System

ECI’s LightSoft NMS is an example of the few systems on the market that manage multi-technology equipment including Carrier Ethernet, DWDM-based Optical, ROADM (News - Alert), SDH/SONET, and MSPP from a single, truly unified management application. In the LightSoft NMS, the same look and feel is used to manage all technologies and equipment from one application, using the same software platform and database; other systems use separate modules for management of different technologies.

Network Management Challenges in MPLS

MPLS technology delivers the QoS required to support real-time voice, video and data services, as well as to support different SLAs that guarantee bandwidth, but it presents several network management challenges at the same time. Network operators now need to manage traffic engineering, guaranteed bandwidth, QoS and resiliency capabilities, as well as to provision and monitor MPLS Label Switch Path (LSP) tunnels to ensure compliance to SLAs.

In some systems, MPLS tunnels are managed through a command line interface (CLI), while Ethernet services are managed using the graphical user interface (GUI). With ECI’s LightSoft NMS, for instance, both tunnels and services are managed via the GUI, making the management task much easier. Many MPLS-based Carrier Ethernet networks require a full mesh of MPLS tunnels between all network nodes, translating into hundreds or even thousands of tunnels on a typical network. Creating these tunnels manually would be a long and painful process, but a unified management application (like LightSoft NMS) includes automation tools that enable the creation of a large set of tunnels by a single action, reducing the time, cost and risk of human error.

A service provider choosing Carrier Ethernet as an extension of existing equipment while managing all the equipment by the same NMS would benefit from lower TCO, shorter implementation time, efficient use of operational staff, and lower integration risks.

Management applications that have a consistent look and feel – regardless of the underlying technology – help service providers introduce new services faster, while saving on training. Automation tools are also critical in Carrier Ethernet networks because of the large number of objects to be created and maintained.

A truly converged system with a rich set of automation tools and a consistent look and feel for Ethernet, DWDM, and SDH/SONET is what many providers want while they save even more by providing a single northbound interface for external integrations.