The method of the present invention provides efficient aggregation of link metrics for a subnetwork (102, 202, 302) in a communication network (100, 200, 300) having a plurality of interconnected subnetworks (102, 202, 302) that includes nodes (A, B, C, D) and links. Link metric values are summarized on a full-mesh topology (202) and encoded by a spanning tree topology (1004). The method encodes the link metric information contained in full-mesh topology with minimum compromise in the capability to recover it.

Method for efficient aggregation of link metrics

Routing a message in a network is efficient (in terms of weight of the path used to carry the message) when nodes know the full topology of the network. This may not be the case in large networks since a network may be composed of smaller autonomous pieces by design or by requirements on performance, with each piece having less than complete information about other pieces. We present a trade-off between the amount of topology information exchanged among these pieces and the efficiency of routing in the network. The large network that we study is a collection of networks connected by boundary nodes. Each boundary node knows the topology of its network and the connectivity of networks to each other. The question addressed here is how much topology information about each network should be distributed to other networks in order to achieve reasonably efficient routing.

Topology distribution cost vs. efficient routing in large networks

The problem of partitioning a large computer network into clusters in order to reduce the amount of network resources consumed by the routing algorithm is addressed. The clustering problem is formulated as a general graph partitioning problem. It is shown that the problem of partitioning a graph into a minimum number of clusters with unit weight vertices and a given weight bound on the cluster size is NP-complete if each cluster is required to be internally connected. It is also shown that if a diameter bound is imposed on the cluster instead of the weight bound, then the problem is NP-complete, even when cluster connectivity is not required. An optimum partitioning algorithm is presented for the latter problem when the graph is a tree. An optimum partitioning algorithm is presented for another problem in which each cluster is required to contain exactly one of a set of specified vertices called cluster heads. >

Some graph partitioning problems and algorithms related to routing in large computer networks

Simulating an application. A method that may be practiced in a computing environment configured for simulating an application modeled by an application model deployed in a performance scenario of a computing system by deploying service models of the application model to device models modeling devices. The method includes referencing a performance scenario to obtain a transaction being modeled as originating from a first device model. The transaction invokes of a first service model. The first service model specifies hardware actions for simulation. The first service model is referenced to determine the hardware actions for simulation and the next referenced service. The next referenced service specifies hardware actions to be added to the transaction and may specify invocation of other service models. A chain of hardware actions is generated by following the invocation path of the service models. The hardware actions are applied to device models to simulate the transaction.

Dynamic software performance models

A new hierarchical location registration is presented for personal communications, and its related call routing through broadband-ISDN is described. The call routing utilizes signaling packets to directly access the lowest registration unit (HLRUO) of portable stations, so that centralized accesses as in GSM systems are avoided. After a description of the model of hierarchical location registration, the average number of registrations at each layer is statistically analyzed. The registration time interval vs. roaming range is derived. Thus, the average time interval for updating location information in the HLRUO is obtained. The performance evaluation of the proposed scheme and a comparison with GSM are outlined. >

https://ieeexplore.ieee.org/iel2/642/6695/00267976.pdf

Performance evaluation of a hierarchical location registration and call routing for personal communications

A hierarchical hybrid adaptive routing algorithm (HHARA) is presented for dynamic large-scale computer communication networks (LSCCN). The performance of the proposed algorithm is evaluated and compared to that of nonhierarchical routing algorithms by simulation experiments on a 50-node network model. The major evaluation criteria are reliability, communication overhead, computation overhead, and average packet delay. A fixed routing algorithm, the most recent ARPANET routing algorithm, and HHARA are compared using simulation experiments. The simulation study indicates that HHARA makes a good balance between the reduction of routing database maintenance overhead, and the global routing capability as well as the local adaptivity to the network changes. >

Performance evaluation of a hierarchical hybrid adaptive routing algorithm for large scale computer communication networks

A survey is presented of present algorithms, with emphasis of a proposed scheme, the hierarchical hybrid adaptive routing algorithm (HHARA). HHARA reduces the size of routing database by dynamically organizing nodes into hierarchically structured clusters so that only partial information is stored and maintained in each site. The responsibility for routing is shared by the routing hierarchy so that the algorithm can maintain the global routing optimality and the local adaptivity at the same time. In this way, the storage, maintenance, communication, and computation overheads can be reduced while the response time to local status changes is kept small. HHARA can be used with either diagram routing or virtual circuit routing. Due to its ability to adapt to the network changes, it is specially useful for dynamic networks such as large military computer communication networks. >

F. Amer

Papers

Performance evaluation of a hierarchical hybrid adaptive routing algorithm for large scale computer communication networks

A survey of hierarchical routing algorithms and a new hierarchical hybrid adaptive routing algorithm for large scale computer communication networks