Network Sales and Services Handbook (Cisco Press Networking Technology)

Which is better, FCAPS, or TMN?

TMN has become separated into two parts: TMN as architecture for telecommunications management and TMN as a set of supporting protocols. Initial TMN proponents and implementations did not differentiate between architecture and protocol and often ran into adversity. The open-standards concept behind TMN was widely accepted, although the underlying protocols were not readily adopted.

The TMN model helps to categorize, prioritize, and specify the responsibilities of telecommunications management products and services. For the first years of TMN's existence, the industry was focused on standard protocol implementation, particularly at the element and network management layers. The future of TMN, however, is not in the protocol domain. TMN will continue as a framework for telecommunications management, but it will become less focused on defining protocols to support the TMN architecture.

FCAPS is the methodology used to implement the TMN standards for network management. Whereas TMN defines how networks, such as ATM, can be managed, FCAPS is the model used to implement the network management architecture.

There is no clear answer regarding which is better, FCAPS, or TMN. As the industry has evolved, TMN has found a niche within the FCAPS model.

Is it necessary to monitor and manage every network device?

No, it is not necessary to monitor and manage every device on a network. Device monitoring and management depends upon the mission-critical nature of that device. For example, it can be considered more worthwhile to an organization to monitor and manage a WAN router or corporate Internet/intranet servers rather than to monitor/manage individual workstations.

Although it is desirable to have visibility into and manage as much of the network as possible, even at the desktop level of granularity, there is a balance between the size and scale of the network and the network management organization itself. It is considered unreasonable for a single network manager to manage a large ATM WAN to the desktop level of granularity (such as routers, switches, servers, hubs, and LAN workstations), when management of the routers and servers is a huge task in and of itself.