Previous | Table of Contents | Next |
For those services (or pieces of services) that do not offer standard management capability, it is still necessary to at least monitor the fault status. Most equipment used in the head end will either have some sort of alarm capability or be controlled by a PC application that will have alarm capability, typically through a RS-232 serial port. These types of devices could still be incorporated as part of a management system through the use of a mediation device.
Exhibit 6 shows the FMP from Hewlett-Packard. It incorporates a mediation device as the first interface to the network management system.
This mediation device is used to map RS-232, SNMP, and CMIP devices into a standard X.733 alarm messaging format. Also built into the mediation device is event correlation, which allows the management system to correlate related alarms (e.g., HFC outages and critical alarms in services) before forwarding onto the network management system. This would, for example, allow only one alarm to be forwarded when hundreds of alarms may be logged into the mediation device.
At the network management layer (shown as alarm management service and utility tools in Exhibit 6), another layer of event correlation takes place. This layer correlates alarms from other head ends or from other types of managed object classes (i.e., head end equipment) to develop root-cause analysis. This is the event correlation that would allow the user, for example, to correlate alarms from the high-speed data service with alarms from the HFC network.
Up to this point, this chapter has discussed monitoring the status of equipment in a HFC network. The other aspect of a management system is to control the equipment that is, some sort of manager/agent application.
Most head end equipment currently either has no management application or has a PC-based application that was designed to be a standalone application. In order for the network management system to control the devices, there needs to be some way to program the devices, either directly or through an agent application.
If the head end devices have some sort of PC application for control, it may be possible to login from a remote terminal on the network management station and control the devices that way. That would allow for centralized control, but does not meet the requirements of the TMN model.
For those devices that do not have a manager/agent application, or some sort of MIB, they cannot be automatically managed by the network management system. Equipment vendors will have to develop a manager/agent application for their devices.
Management for HFC networks is in its infancy stage. A majority of the equipment vendors are in the process of developing a network management strategy for their devices and services, which will include the development of a manager and agent application.
Currently, most vendors are leaning toward the use of SNMP to control their devices. Because of the widespread acceptance of SNMP in the computer network and systems management, there are hundreds of development tools that make the development task much easier than CMIP. CMIP does have some performance capabilities that far exceed SNMP, and some equipment used with a HFC network (e.g., telephone switches, SONET gear) may use CMIP instead of SNMP.
For the short-term (i.e., over the next five years), the management protocols used will probably include SNMP, TL-1, CMIP, and other, non-standard forms. Thus the network management system used will have to be flexible, one that can handle many protocols yet provide a common, standards-based operating environment.
With the network management system, it will be possible to present the management information for all network elements and services in one consistent GUI and provide for centralized management. With the integrated information, it will be possible to proactively monitor the HFC network, and eventually predict when the HFC network will need maintenance or when it will start to affect the digital services, thus allowing for a reliable, high-speed communications network for many types of services.
Previous | Table of Contents | Next |