Shaygan Kheradpir

Dynamic bandwidth-allocation and path-restoration in SONET self-healing networks

This paper presents a new scheme for real-time bandwidth allocation and path restoration (BARS) in mesh networks via SONET wideband digital cross-connect systems (WDCSs) in response to demand and load dynamics and link and/or node failure(s). The scheme dynamically maximizes bandwidth allocation while ensuring full service restorability. Since the physical network capacity is limited, sometime not all the demand can be accommodated under the full restorability requirement. This demand in SONET BARS is rejected fairly at the network boundary even if capacity for allocation is available. Bandwidth allocation and fair demand admission are optimized jointly under the full restorability requirements. The implementation of SONET WDCS does not need excessive storage. An efficient parallel algorithm for solving the optimization problem is also presented. The algorithm produces superior spare capacity assignments compared to the results in the literature.

Design and Deployment of an Integrated Network Management System for a Large Telco Network

Defining the architecture for an integrated network management system requires an understanding of the relationship between network services and network equipment., the network domains to be managed, the management functions to be provided, and objectives for integration. Designing and deploying a system, on the other hand, further requires solutions to a range of practical issues in the areas of software engineering, communications reliability, data integrity, system performance, the capabilities of new intelligent network elements, the limitations of the embedded base network, etc.

Real-time traffic management by a parallel algorithm

The joint access-control and routing problem for distributed networks is formulated as an equilibrium programming problem (EPP). The strategy, for an upcoming control period, decreases call blocking and balances network load by maximizing network residual capacity, and fairly rejects at the source the source-destination demands that are expected to exceed network capacity. The EPP formulation allows for both decentralized implementation of the joint access control and routing problem and massive parallelization of the optimization procedure to satisfy real-time requirements. The computational complexity of the algorithm decreases proportionally with the number of processors used. The convergence of the decentralized algorithm to the network-wide optimum is proved. Compared to the case where subnet EPPs are solved independently by each controller, simulation results show significantly better utilization of network resources when subnet controllers jointly solve the network-wide EPP. Performance analysis of the algorithm and numerical studies show that the algorithm is well suited for real-time implementation in large networks or internetworks. >

Managing the network manager

A network management and control simulator (NEMACS) software testbed for developing, testing, and integrating different network management (NM) techniques for multiservice circuit-switched networks is discussed. NEMACS is capable of applying different NM strategies to a plethora of simulated network scenarios that include networks of differing size, speed, transport topology, control, and management architectures. NEMACS simulates networks by modeling the behavior of various network modules: call transport modules (CTMs), call control modules (CCMs), and network control modules (NCMs). The implementation of NEMACS software and four examples of how NEMACS has been used to rapidly prototype NM techniques are presented. The examples deal with focused overload in a simple network, predictive access-control and routing strategy, decentralized management, and multiclass traffic control.<<ETX>>

Integrated network management and control for interactive video dial tone networks

The emerging interactive video dial tone (VDT) services pose some unique requirements for real-time network monitoring and control. To support the roll-out of VDT-based networks and services, GTE is developing new network management applications on its TONICS (Telephone Operations Network Integrated Control System) platform. TONICSs applications are embedded in a high availability software platform providing distributed processing. The article describes the real-time management requirements of VDT networks, provides an overview of the TONICS integration platform, outlines a network management and control architecture for VDT networks, illustrates example VDT management applications, and discusses the deployment issues. >