In this paper we present a prototype implementation of a management scheme that can be used to dynamically manage Guaranteed Performance Connection (GPC) services in Integrated Services Networks. These services are required to support the wide range of quality-of-service parameters desired by many useful applications. The GPC services provide performance guarantees in terms of throughput, delay, delay jitter and loss rates, and adopt a connection-oriented, fixed-route, reservation-oriented approach to achieve these guarantees. In such an approach, resource allocation and route selection decisions are usually static (i.e. they are made before the start of the communication on the basis of resource availability and real-time network load at that time, and are usually kept for the duration of the communication). This static approach limits the flexibility of these GPC services. In our previous work we presented our solution to this lack of flexibility. This solution, the Dynamic Connection Management (DCM) Scheme, provides the network with the capability to dynamically modify the traffic characteristics, the performance requirements, and the route of any existing guaranteed-performance connection (C. Parris, H. Zhang and D. Ferrari, ACM Multimedia Systems Journal, 1 (6) (1993) 267–283). We also presented several simulation experiments that proved the feasibility of the scheme and analyzed its performance. In this work we complete this proof of concept by implementing the DCM scheme and conducting several initial measurement experiments on this prototype. The implementation utilized the data delivery protocols of the Tenet Real-Time Protocol suite and the Simple Network Management Protocol version 1 (SNMPv1) as the control or management protocol. The measurement experiments indicated that, although the scheme is indeed useful, there are several limitations caused by the use of SNMPv1.

Most of the solutions proposed to support real-time (i.e. guaranteed performance) communication services in packet-switching networks adopt a connection-oriented and reservation-oriented approach. In such an approach, resource allocation and route selection decisions are made before the start of the communication on the basis of resource availability and real-time network load at that time, and are usually kept for the duration of the communication. This rather static resource management approach has certain limitations: it does not take into account (a) the dynamicity of the communicating clients; (b) the dynamicity of the network state; and (c) the tradeoff between quality of service and network availability, thus affecting the availability and flexibility of the real-time network services. Availability is the ability of the network to accommodate as many real-time clients as possible, while flexibility is the ability to adapt the real-time services to changing network state and client demands. The authors present the dynamic connection management (DCM) scheme, which addresses these issues by providing the network with the capability to dynamically modify the performance parameters and the routes of any existing real-time connection. With these capabilities, DCM can be used to increase the availability and flexibility of the guaranteed performance service offered to the clients.>