Multiplex communications – Communication techniques for information carried in plural... – Combining or distributing information via time channels
Reexamination Certificate
1999-09-27
2001-09-04
Vu, Huy D. (Department: 2843)
Multiplex communications
Communication techniques for information carried in plural...
Combining or distributing information via time channels
C375S362000
Reexamination Certificate
active
06285688
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to telecommunications networks. More particularly, the present invention relates to managing a telecommunications network containing diverse network elements conforming to a variety of telecommunications protocols.
2. Related Art
As telecommunications networks become more complex, telecommunication network service providers require increasingly capable network management systems. The network management systems face substantial hurdles to acceptance by network service providers. One such hurdle is that the network management systems have to manage networks comprised of network equipments that comply with a variety of interface standards. An example of such an interface standard is the well-known common management interface protocol (CMIP). Not only must a telecommunications network management system manage diverse network elements, but it must also manage network growth and/or modification. Conventional telecommunication network management systems do not provide a mechanism for representing the physical network in an efficient manner to facilitate network design and maintenance. Nor do they adequately provide for representing a physical network's evolution to a new configuration.
Moreover as the networks become more capable telecommunication services providers are faced with increased service demand. Increased service demand, in turn, requires increased communication bandwidth. To meet the increased communication bandwidth requirements, many service providers have turned to optical communications. In response to the increased demand for optical telecommunications equipment, a number of vendors have entered the marketplace. To allow telecommunications network designers to connect equipments from various vendors together into a heterogenous fiber optic telecommunications networks, synchronization (also referred to as timing) interconnectivity standards had to be developed. One such standard is the Synchronous Optical NETwork (SONET). An overview of SONET can be found in John Bellamy, Digital Telephony, 403-26 (John Wiley & Sons, Inc. 1991), hereby incorporated by reference.
A SONET network distributes synchronization in the SONET optical signal rate. To do so, a source clock produces an electrical timing signal to be distributed. The source clock is an extremely stable clock. Such a clock is generally referred to as a Stratum-1 source. A Stratum-1 source is a highly reliable timing source (having a free running inaccuracy on the order of one part in 10
11
).
The electrical timing signal feeds a frequency multiplier in a SONET transmitter. The frequency multiplier multiplies the timing signal to generate a derived SONET optical signal rate. The SONET transmitter transmits data to a SONET receiver at the derived optical signal rate The SONET receiver extracts the derived optical rate. The SONET receiver divides the extracted optical rate by the multiplication factor applied by the frequency multiplier to produce the distributed electrical timing signals.
SONET equipment can adapt to network equipment failure by modifying the synchronization topology of the network. However, such modification may cause problems in the resulting network synchronization topology. For example, the modification can result in timing loops and loss of traceability to a Stratum-1 source. Modern networks ensure traceability of timing back to a Stratum-1 source to ensure timing stability. A timing loop occurs when a particular piece of tiling equipment is referred to more than once in a particular path. A path connects a source of timing to a user of timing. A timing loop can result in the complete loss of a particular path. This is because the path's timing continually tries to catch itself, eventually culminating in the loss of synchronization. Thus, it is desirable to design a telecommunications network that does not have timing loops, and that has traceability back to Stratum-1. Moreover, as a telecommunications network reconfirms itself to circumvent network failures, the restored configuration must avoid timing loops and maintain Stratum-1 traceability.
What is required therefore is a telecommunications network management system to aid in the design and maintenance of a robust telecommunications network. The system should be capable of managing diverse network equipments conforming to a variety of interface standards. The system should also be able to determine the current state of a network, restore it to a state satisfying various engineering design guidelines. The network management system should be flexible enough to allow upgrades (i.e., addition of new equipment and changes in network topology) without violating the engineering design guidelines.
SUMMARY OF THE INVENTION
The present invention is directed to a system and method for managing a telecommunications network. The system and method employs a network management architecture that provides an overlay in which network management functions are performed. The network management architecture includes a workstation function subsystem that provides a graphical user interface (GUI), a telecommunications management network (TMN) subsystem, a database subsystem, and an object request broker (ORB). Using the GUI, a user (e.g., a network designer) can interact with an object model of the physical telecommunications network. The TMN subsystem provides an object model of the telecommunications network. The current configuration of the managed network is referred to as a “current” view. The object model can represent a configuration of the network projected to some future date. The projected configuration of the managed network is referred to as a “future” view. The database subsystem stores records that are used to construct “current” and “future” views of the network. The ORB maps objects from a first object-oriented paradigm to a second object-oriented paradigm for use by the GUI.
One aspect of the present invention is a novel network management architecture that provides sufficient flexibility to allow for management of a modern telecommunications network. The telecommunications network can contain diverse network equipments that conform to differing communications protocols. The network management architecture contains a management information base. The management information base contains a run-time object model of the telecommunications network. The run-time model can represent the projected configuration of the network at some future date.
The run-time object model generally conforms to the TMN standard. Because the TMN standard does not adequately model the physical connectivity of the network (e.g., path traces between network elements), the present invention includes extensions to the conventional TMN object models. The extensions to conventional TMN object models allow the present invention to more realistically model and display the telecommunications network. Thus, the software architecture stores an object model representation of the physical network. The stored object model representation represents the current configuration of the network or the configuration of the network projected to some future date. In this specification, an object model representation of a telecommunications network is also referred to as an object store or a workset.
The present invention also provides a workset manager. The workset manager interacts with a database having records that are used to construct various network configurations. By so interacting, the workset manager provides the desired run-time model of the network to the TMN subsystem. Using a network management architecture designed according to a preferred embodiment of the present invention, a network designer can simulate the behavior of the network to proposed modifications of the network. Modifications include adding, removing, or changing the configuration of network elements, as well as modifying the topology of the telecommunications network. By simulating modifications to the network conf
Cooley Von A.
Franklin Thomas Dennie
Henderson Gregory Scott
Perry Wayne B.
Sanders, Jr. Ed J.
MCI Communications Corporation
Vu Huy D.
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