This letter proposes an efficient implementation method for a binary feedback switch, called EFCI/RELAY, which can reduce the feedback delay of the congestion status of a switch in multiple-hop network environments. At each transit switch, this method relays the EFCI-bit contained in an incoming data cell to the head-of-line cell with a corresponding VC which is waiting for transmission in the output buffer. Simulation results show that the proposed method can achieve a lower queue length while maintaining a higher link utilization.

In this paper, we first investigate the problems of the existing branch point algorithms for available bit rate (ABR) multicast connections in ATM networks, and then propose various solutions for resolving those problems. By combining these solutions, we also propose a new efficient and scalable branch point algorithm. In the proposed algorithm, each branch point stores the feedback information on a per-branch basis for each virtual connection and only passes BRM cells returning from the farthest destination. Simulation results show that the proposed algorithm can provide a good fairness, a higher efficiency and an excellent scalability, compared with the existing algorithms.

This paper investigates the performance of relative rate (RR) switch algorithms for available bit rate (ABR) flow control in asynchronous transfer mode (ATM) networks. An RR switch can be implemented differently according to the congestion detection and notification methods used. This paper proposes three implementation schemes for an RR switch using various congestion detection and notification methods, and then analyzes the allowed cell rate (ACR) of a source and the queue length at a switch in steady state. The upper and lower bounds for the maximum and minimum queue lengths are also determined for each scheme, respectively, thereby investigating the effects of ABR parameter values on a queue length. Furthermore, a selection method for rate increase factor (RIF) and rate decrease factor (RDF) parameter values is suggested to prevent buffer overflow and underflow.

As the network speed becomes faster and requirements about various services are increased, a number of groups are currently developing technologies aimed at evolving and enhancing the capabilities of existing network. A Next-Generation Network (NGN) is defined as a hybrid telecommunications network that employs new distributed processing techniques to provide all types of services. By integrating the Intelligent Network (IN) technology and the Mobile Agent (MA) technology we can support service flexibility and service portability in NGN. In this paper, we propose a caching-based mobile agent model for NGN and analyze the performance of this model. The mobile agent technology increases the service portability and the caching strategy does the service reusability. Each Physical Entity (PE) has MAs within their repository through the caching strategy and processes service requests from users without the control of the central system such as Service Control Point (SCP). Therefore, we can decrease the total network load and the response time for user requests.