Connectionless Service in ATM Networks

9305376 Gerla这个项目涉及到在ATM网络中支持无连接服务的问题。这个问题的紧迫性源于需要将局域网和城域网（通常以无连接模式运行）互连到面向连接的ATM。这个问题相当具有挑战性，因为ATM网络要求用户建立连接，并提前声明每个连接上的预期流量。然后，网络使用这些信息为各个用户分配带宽。另一方面，无连接源本质上是不可预测的，因此避开了ATM带宽分配策略，并可能损害网络效率。本课题研究了无连接服务器（CLS）覆盖网络方案。该方案可以有效地处理ATM中的无连接流量。研究了各种设计选项（拓扑连接性、带宽分配、缓冲区管理等），并开发了选择这些选项的性能模型和标准。CLS方案将与其他无连接支持方案（带宽保留和即时传输）进行比较，并评估各自的优缺点。最后，结合所有方案的特点的混合方案将被检查，试图结合他们的利益，同时避免他们的陷阱。＊＊＊

9305376 Gerla This project involves the problem of supporting connectionless service in an ATM network. The urgency of this problem stems from the need to interconnect LANs and MANs (typically, operated in a connectionless mode) to the connection oriented ATM. The problem is quite challenging because the ATM network requires that users set up connections and declare in advance the expected traffic on each connection. The network then uses this information to allocate bandwidth to individual users. Connectionless sources, on the other hand, are by their nature unpredictable, thus eluding the ATM bandwidth allocation strategy, and potentially compromising network efficiency. In this project, a scheme - the Connectionless Server (CLS) overlay network - is investigated. This scheme permits efficient handling of connectionless traffic in ATM. Various design options (topology connectivity, bandwidth allocation, buffer management, etc.) are examined, and performance models and criteria for their selection are developed. The CLS scheme will be compared with other connectionless support schemes (Bandwidth Reservation and On-the-Fly Transmission) and the respective pros and cons will be evaluated. Finally, a hybrid scheme combining features of al of the schemes will be examined in an attempt to combine their benefits while avoiding their pitfalls. ***