Electrical computers and digital processing systems: multicomput – Computer network managing
Reexamination Certificate
1998-11-16
2003-05-13
Sheikh, Ayaz (Department: 2155)
Electrical computers and digital processing systems: multicomput
Computer network managing
C709S201000, C709S202000, C709S203000, C709S220000, C709S223000, C709S224000, C370S902000, C710S220000, C707S793000
Reexamination Certificate
active
06564258
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to network management in communications networks, and particularly although not exclusively to the detection of server layer re-configurations which affect client layers in a communications network operating a layered transmission protocol structure.
BACKGROUND TO THE INVENTION
In prior art synchronous communications networks, for example of the synchronous digital hierarchy (SDH) type, incorporating synchronous optical network (SONET) options in accordance with ITU-T recommendation G.707, comprising a plurality of node equipment, communicating over a plurality of links, eg fiber optic links, reconfiguration of a network following physical modification to the network, for example addition or deletion of a node equipment, is carried out using a network management system comprising one or more graphical user interfaces, operated by one or more human network operators. In prior art network management systems, a network operator is presented with a visual display screen on a graphical user interface, displaying a plurality of icons representing node elements, links, connections and trails between node elements. Upon physical reconfiguration of part of a network, eg by reconnection of existing node elements in a different manner, or by addition or deletion of a node element, logical reconfiguration of the network including reconfiguration of routes, trails, connections is made by manual input of commands by a human network operator at the graphical user interface. For example, on adding a new node to an existing synchronous network, a network operator may visually inspect a two dimensional graphical visual representation of a section of a network on a visual display device, and by inspection of the visual display take a decision on how to re-route a trail or path in a synchronous network through a new node. Where the trail or path extends over a large number of nodes of the network, some of those nodes may be under control of a second network operator operating from a remote position. Under these circumstances, the two operators need to communicate with each other, eg by telephone, to discuss changes to the network, before implementing those changes by typing in keystroke commands at the respective graphical user interfaces of their network management systems.
However, prior art communications networks are highly complex in nature, typically operating a plurality of protocol layers comprising several server layers, eg physical layers and optical layers, and client layers, comprising service layers and the like. Changes to the server layers, such as physical replacement or reconfiguration of the node equipment or logical reconfiguration of one or more nodes at the server layers have consequences for reconfiguration of all client layers supported by those server layers. Thus, although the network operators are presented with a visual display at which visual representations of various client and server layers may be presented, due to the inherent size and complexity of communications networks, the impact of changes at the server layers may not be fully realized by human network operators, and reconfiguration of client layers upon changes to server layer functionality implemented by means of visual inspection by one or more network operators and manual entering of commands into a graphical user interface may not provide the optimum reconfiguration of a network. Although it may be possible to find reconfiguration solutions by visual inspection, a total range of possible reconfigurations is greater than a human operator can investigate. In order for the human network operator to produce any reconfiguration solution at all, this may entail a downtime on the corresponding part of the network from the order of around 10 minutes to days depending upon the complexity of connections to a node.
Further, prior art reconfigurations of synchronous networks operate only by using aggregates, and so re-routing solutions are found only when aggregates are de-multiplexed into tributaries.
SUMMARY OF THE INVENTION
One object of the present invention is to optimize the reconfiguration of a communications network at a set of clients layers, following a reconfiguration of the network at a server layer.
Another object of the present invention is to provide an automated network management tool for finding a plurality of possible reconfigurations of a communications network at a set of client layers, in consequence of a change or proposed change to a network at one or more server layers of the network.
A further object of the present invention is to enable a quicker time to reconfiguration of a network after changes to a network topology, either physical or logical.
Another object of the present invention is to find re-routing solutions in a network which are non-obvious to a human operator, or which would be practically impossible for a human operator to find.
According to a first aspect of the present invention there is provided a method of detecting an effect of a network topology change in a network comprising a plurality of resources arranged in a plurality of layers wherein resources at a client layer are dependent upon resources at a server layer, said method comprising the steps of: maintaining an object database describing a plurality of resources of said communications network, said object database comprising a plurality of instances representing physical and logical resources; modifying individual ones of said plurality of instances when a said resource is re-configured by setting a state of a said instance; and detecting at least one client layer resource affected by a change to a said server layer resource.
Said plurality of instances may include instances selected from the set: an instance representing a node entity; an instance representing an endpoint; an instance representing a trail; an instance representing a trail termination point; an instance representing a connection; an instance representing a connection termination point; an instance representing a link connection; an instance representing a port; an instance representing a sub network connection; an instance representing a link; an instance representing a link termination point.
Said method may comprise the steps of: receiving a signal for deletion of a trail; and in response to said received signal, reading said object database to determine whether a trail subject of said delete signal supports a client trail.
Said method may comprises the steps of: receiving a signal for deletion of a trail; on receipt of said delete signal determining whether a trail subject of said signal is supporting a client trail; and if said trail subject of said delete signal is supporting a client trail, setting a data describing said trail to a state signifying said trail is supporting at least one client trail.
The method may further comprise the step of setting data describing a said client trail to a state signifying deletion of said trail is inconsistent with supporting said client trail.
According to a second aspect of the present invention there is provided a method of re-routing a trail in a synchronous communications network, said method comprising the steps of: receiving a signal for creation of a new trail; for each of a pair of endpoints, identifying data describing said endpoint; determining whether said endpoint data is in a state signifying that said endpoint is capable of supporting said new trail and; if said endpoint data of each said endpoint is in a state signifying that said new trail can be created, creating said new trail.
According to a third aspect of the present invention there is provided a method of re-routing a client trail supported by a server trail, in a synchronous communications network, said method comprising the steps of: receiving a signal denoting that a new trail is to be created; identifying data describing at least one endpoint of said t rail to be created; determining from said endpoint data whether creation of said trail conflicts with another already created t
Lee Mann Smith McWilliams Sweeney & Ohlson
Nguyen Thu Ha
Nortel Networks Limited
Sheikh Ayaz
LandOfFree
Detection of network topology changes affecting trail... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Detection of network topology changes affecting trail..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Detection of network topology changes affecting trail... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3007497