Showing papers on "Virtual routing and forwarding published in 1996"

IP Encapsulation within IP

Abstract: This document specifies a method by which an IP datagram may be encapsulated (carried as payload) within an IP datagram. Encapsulation is suggested as a means to alter the normal IP routing for datagrams, by delivering them to an intermediate destination that would otherwise not be selected by the (network part of the) IP Destination Address field in the original IP header. Encapsulation may serve a variety of purposes, such as delivery of a datagram to a mobile node using Mobile IP.

Flow labelled IP: a connectionless approach to ATM

Abstract: A number of proposals for supporting the Internet protocol (IP) over ATM are under discussion in the networking community including: LAN emulation, classical IP over ATM, routing over large clouds, and multiprotocol over ATM. Each of these proposals hides the real network topology from the IP layer by treating the data link layer as a large, opaque, network cloud. We argue that this leads to complexity, inefficiency and duplication of functionality in the resulting network. We propose an alternative in which we discard the connection oriented nature of ATM and integrate fast ATM hardware directly with the IP, presenting the connectionless nature of the IP. We use a "soft" state in the ATM hardware to cache the IP forwarding decision. This enables further traffic on the same IP flow to be switched by the ATM hardware rather than forwarded by the IP software. We claim that this approach combines the simplicity, scalability, and robustness of the IP with the speed, capacity, and multiservice traffic capabilities of ATM.

System providing for multiple virtual circuits between two network entities

Abstract: Computers sending IP datagrams over an ATM network are generally capable of operating multiple simultaneous virtual circuits over the network. However, in doing so, they normally only set up one virtual circuit to each destination IP address so that in order to test the simultaneous operation of N virtual circuits by a computer under test, N target computers are needed. To enable a single computer to provide the destination endpoints for multiple virtual circuits from a computer under test, both computers are allocated a plurality of virtual IP addresses and the target computer is additionally provided with a module running address-changing processes that avoids the IP layers of both computers from rejecting IP datagrams addressed with the virtual IP addresses. As a result, each computer can be addressed with any of a plurality of IP addresses and each will result in the creation of a respective virtual circuit between the computers.

Flow Labelled IP: Connectionless ATM Under IP

Abstract: IP traffic on the Internet and private enterprise networks has been growing exponentially for some time. This growth is beginning to stress the traditional, processor based design of current day routers. Switching technology offers much higher aggregate bandwidth but presently only offers a bridging solution. Various proposals are under way to support IP routing over ATM switching technology; however, these proposals hide the real network topology from the IP layer by treating the data-link layer as a large, opaque, network cloud. We argue that this leads to complexity, inefficiency and duplication of functionality in the resulting network. We propose an alternative in which we discard the connection oriented nature of ATM and integrate fast ATM hardware directly with IP, preserving the connectionless nature of IP. We use “soft” state in the ATM hardware to cache the IP forwarding decision. This enables further traffic on the same IP flow to be switched by the ATM hardware rather than forwarded by IP software. We claim that this approach combines the simplicity, scalability, and robustness of IP with the speed, capacity, and multiservice traffic capabilities of ATM.

Adaptive routing in k-ary n-cube multicomputers

Abstract: Wormhole routing makes the communication latency insensitive of the network diameter and reduces the buffer size of each router. It has been widely adopted in many new generation distributed memory multiprocessor systems (DMMPs). The concept of virtual system is invented for deadlock-free routing design. Using a great deal of virtual channels is quite expensive to be implemented in practice and is not limitless. In this paper experimental results are given to evaluate the tradeoff between network congestion delay and throughput. Some results show that the congestion delay does not reduce visibly when the number of virtual channels is greater than that of internal channels by 2. A reasonable number of virtual channels can be derived from the results. A virtual networks system using only four virtual networks, two virtual channels in each direction, is presented. It shows that the minimum number of virtual networks to support a partially adaptive, minimal and deadlock free routing in k-ary n-cubes is just four. It uses only four virtual networks but can get a high degree of adaptiveness and high traffic capacity. Simulation results are presented to verify the performance.

LIS (logical IP subnet) over ATM

Abstract: We propose a simple technique that realizes logical Internet protocol (IP) subnetworks (LIS) in an ATM environment. Our proposal supports both autoconfiguration and semi-autoconfiguration, in which the host specifies some aspects of its IP address. It also supports host mobility, while allowing optimal routing within the ATM network without requiring modification to the IP implementations on every host. Other methods for supporting mobility entail either inefficient routing or changes to all the hosts involved. The proposal requires only minor protocol extensions, which are already under discussion in the protocol community. We also present simulation results illustrating the improvement in traffic load and concentration achieved by this approach.

System and method for establishing communications over a network

Abstract: In a communication system capable of establishing communication with a mobile party having a Personal Telephone Number the mobile party uses a two-way pager (10) to transmit a forwarding number to a paging service (28). The paging service relays the forwarding number to a Customer Routing Point (34) where the number is stored. Whenever a caller (12) initiates a call to the mobile party by dialing the mobile party's Personal Telephone Number, the Customer Routing Point (34) is notified. The Customer Routing Point then cross-references the Personal Telephone Number with the forwarding number and forwards the call to a terminating telephone (32) associated with the forwarding number. In one possible embodiment an adjunct is used in conjunction with the Customer Routing Point to offer call forwarding service on both a call by call basis and a registration basis.