This paper investigates the performance of two Layer 3 low latency handoff protocols proposed by the IETF, namely Pre-and Post-Registration. These protocols use Layer 2 triggers to reduce the built-in delay components of Mobile IP. We propose a simple analytical model that allows assessing the packet loss and the delay characteristics of these protocols. We describe several handoff implementations over a wireless access based on the IEEE 802.11 standard and analyze several implementation issues. Finally we study the scalability of the protocols using an OPNET simulation.

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In this paper we evaluate a low latency handoff protocol for MIPv4, the Post-Registration handoff method. This mechanism proposed by the IETF tries to improve the performance of Hierarchical Mobile IP by decreasing the handoff latency. We give a detailed description of the protocol behavior by means of an ns simulation and propose a simple queuing model to study the influence of various parameters on the protocol performance.I.

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Absfract-I n this paper we address the design of a packet buffer for future high-speed routers that support line rates as high as OC-3072 (160 Gbls), and a high number of ports and service classes.We describe a general design for hybrid DRAWSRAM packet buffers that exploits bank organization of DRAM. This general scheme includes some designs previously proposed as particular cases.Based on this general scheme we propose a new scheme that randomly chooses a DRAM memory bank for every transfer hetaeen SRAM and DRAM. The numerical results show that this scheme nould require an SRAM size almost an order of magnitude lower than previously proposed schemes without the problem of memory fragmentation.

Abstract. Demand for mobile network access is having a huge increase nowadays. Cellular networks are being deployed to cope with a high number of users. Several IP micro-mobility protocols have been proposed to handle routing and handoffs inside cellular networks. In this paper the HAWAII micro-mobility protocol is analyzed by means of an analytical model. A detailed description of the handoff procedure is given and illustrated by means of traces obtained from simulation. Several of the system details are taken into account in the analytical model. This allows us to investigate the influence of various system parameters (e.g. cell overlap area, beacon latency, forwarding buffer capacity, etc.) on the system performance for constant bit rate (UDP) traffic. The results are validated by means of simulation results obtained with the network simulator (ns).

Abstract-In order to support the enormous growth of the Internet, innovative research in every router's subsystem is needed. In this paper we focus our attention on packet buffer design for routers supporting high-speed line rates. More specifically, we address the design of packet buffers using Virtual Output Queuing (VOQ) discipline, which are used in most modern router architectures. The design is based on a previously proposed scheme that uses a combination of SRAM and DRAM modules. We propose a storage scheme that achieves a conflict-free memory bank organization. This leads to a reduction of the granularity of DRAM accesses, resulting in a decrease of storage capacity needed by the SRAM. In the DRAM/SRAM scheme, SRAM memory bandwidth needs to fit the line rate. Since memory bandwidth is limited by its size, searching for memory schemes having a small SRAM size arises as an essential issue for high speed line rates (e.g. OC768, 40 Gbps and OC3072, 160 Gbps).

Achieving QoS (Quality of Service) in Mobile Ad-hoc NETworks (MANET) has been a research topic in the last years. In this paper we describe a QoS reservation mechanism for Routing Ad-hoc Networks. The mechanism is targeted for sources requiring a bandwidth allocation. The mechanism is based on the knowledge of the bandwidth requirements of the neighbors of a node and the interferent nodes in the cover area of each node. We describe as the protocol could be integrated in AODV and OLSR. We also give simulation results showing the advantages of our reservation scheme.