Showing papers on "Zone Routing Protocol published in 1990"
01 Dec 1990
TL;DR: This RFC specifies an integrated routing protocol, based on the OSI Intra-Domain IS-IS Routing Protocol, which may be used as an interior gateway protocol (IGP) to support TCP/IP as well as OSI.
Abstract: This RFC specifies an integrated routing protocol, based on the OSI Intra-Domain IS-IS Routing Protocol, which may be used as an interior gateway protocol (IGP) to support TCP/IP as well as OSI. This allows a single routing protocol to be used to support pure IP environments, pure OSI environments, and dual environments. This specification was developed by the IS-IS working group of the Internet Engineering Task Force.
448 citations
Patent•
18 Sep 1990TL;DR: In this article, the authors propose a routing method that routes cells which are transferred through one of a plurality of paths within an asynchronous transfer mode (ATM) switching system (50, 10) selected by routing information.
Abstract: A routing method routes cells which are transferred through one of a plurality of paths within an asynchronous transfer mode (ATM) switching system (50, 10) selected by routing information. The routing method includes the steps of adding first routing information to incoming cells at an input stage of the ATM switching system when supplying the cells to the ATM switching system, generating a route switching confirmation cell in response to a route switching instruction and for adding second routing information to incoming cells thereafter so as to supply the route switching confirmation cell and the cells added with the second routing information to the ATM switching system, where the second routing information is different from the first routing information and is determined by the route switching instruction, comparing routing information of the cells with the second routing information at an output stage of the ATM switching system in response to the route switching instruction, outputting each cell from the ATM switching system having routing information different from the second routing information as it is, and temporarily storing each cell from the ATM switching system having routing information identical to the second routing information and reading out and outputting the stored cell after the route switching confirmation cell is output from the ATM switching system.
127 citations
03 Jun 1990
TL;DR: Analytical results show that in conjunction with trunk reservation, this alternate-path routing rule can offer a stable throughput at high traffic conditions and can increase the call carrying capacity by about 20% under a blocking requirement of 10/sup -2/ on a fully connected symmetrical nonhierarchical network.
Abstract: An analysis is made of an alternate-path routing rule called maximum free circuit routing (MFCR). In the use of MFCR, a call is routed to the alternate path that has the maximum number of free circuits when the direct path is blocked. Analytical results show that in conjunction with trunk reservation, this routing rule can offer a stable throughput at high traffic conditions and can increase the call carrying capacity by about 20% (compared to direct path routing) under a blocking requirement of 10/sup -2/ on a fully connected symmetrical nonhierarchical network. >
42 citations
01 Aug 1990
TL;DR: It is concluded that an architecture based upon source routing, a link state algorithm, and policy information in the link state advertisements, is best able to address the long-term policy requirements of inter-AD routing.
Abstract: Policy Routing (PR) is a new area of development that attempts to incorporate policy related constraints on inter-Administrative Domain (AD) communication into the route computation and forwarding of inter-AD packets.Proposals for inter-AD routing mechanisms are discussed in the context of a design space defined by three design parameters: location of routing decision (i.e., source or hop-by-hop), algorithm used (i.e., link state or distance vector), and expression of policy in topology or in link status. We conclude that an architecture based upon source routing, a link state algorithm, and policy information in the link state advertisements, is best able to address the long-term policy requirements of inter-AD routing. However, such an architecture raises several new and challenging research issues related to scaling.
37 citations
02 Dec 1990
TL;DR: A novel routing protocol for computer networks is designed by combining two routing protocols that adapt to changes in the network topology that has a wide domain of applicability that does not depend on the frequency of changes inThe network topologies.
Abstract: A novel routing protocol for computer networks is designed by combining two routing protocols that adapt to changes in the network topology. The first routing protocol is expensive to operate but yields shortest-paths in the networks; therefore, it is best used when changes in the network topology are rare. The second routing protocol is not as costly to operate, but may yield longer paths; hence, it is best used when changes in the network topology are frequent. By combining these two protocols, the resulting protocol has a wide domain of applicability that does not depend on the frequency of changes in the network topology. >
31 citations
24 Jun 1990
TL;DR: A new methodology is presented for the solution of the multilayer routing problem that has the potential to outperform channel based multi-layer routing algorithms by expanding the routing regions to include areas over the cells by dedicating two routing layers for over-cell routing.
Abstract: A new methodology is presented for the solution of the multilayer routing problem that has the potential to outperform channel based multi-layer routing algorithms by expanding the routing regions to include areas over the cells. It is assumed that four routing layers are available. Routing is completed in two steps; a selected group of nets is routed in the between-cell areas using existing channel routing algorithms and the first two routing layers. Then the remaining nets are routed over the entire layout area, between-cell and over-cell areas, using a new two-dimensional router and the next two routing layers. The router used for over-cell routing recognizes arbitrarily sized obstacles, for example, due to power and ground routing or sensitive circuits in the underlying cells. The proposed router was tested on a number of macro-cell layout examples. Advantages of dedicating two routing layers for over-cell routing is illustrated. Results show a significant reduction in total layout area, wire length and number of via when compared to results obtained using two-layer or multi-layer channel routing methods.
21 citations
CNET1
TL;DR: The evolution of circuit-switched networks is analyzed with respect to the functional innovations that allowed for new traffic controls and the technical alternatives for routing techniques and their integration with congestion and flow control are considered.
Abstract: The evolution of circuit-switched networks is analyzed with respect to the functional innovations that allowed for new traffic controls. The technical alternatives for routing techniques and their integration with congestion and flow control are considered. The performance of dynamically controlled networks is analyzed in the framework of research done at the Centre National d'Etudes des Telecommunications (CNET) together with studies carried out in other research laboratories. Comparisons are made of dynamic routing versus fixed hierarchical routing and time-dependent routing versus adaptive routing. For adaptive routing, centralized and isolated methods are compared. The benefits of advanced control methods are summarized. >
20 citations
03 Jun 1990
TL;DR: Admission control and routing in circuit-switched networks are investigated with two types of traffic: wideband with delayed call set up and narrowband operating in loss mode, finding state-dependent routing to be superior to direct routing and load sharing routing.
Abstract: Admission control and routing in circuit-switched networks are investigated with two types of traffic: wideband with delayed call set up and narrowband operating in loss mode. Markov decision theory is used to construct a state-dependent routing policy. Optimality conditions for a load sharing routing are derived from the first-order Kuhn-Tucker equations. These models together with a direct routing scheme are used in a simulation study to determine the best approach for control of traffic with delayed call setup. State-dependent routing is found to be superior to direct routing and load sharing routing, although its operation is much more complex. >
15 citations
01 Aug 1990
TL;DR: The main idea behind the approach is to use a “dynamic synchronizer”, which transforms a dynamic asynchronous network into static synchronous one, which is an important methodology in design and analysis of communication protocols.
Abstract: In this paper, we survey the existing methods for designing shortest paths routing algorithms for dynamic networks. We compare them based on worst-case communication and message complexity, and suggest new approach that yields a protocol with linear time and polynomial communication.The main idea behind our approach is to use a “dynamic synchronizer”, which transforms a dynamic asynchronous network into static synchronous one. We believe this is an important methodology in design and analysis of communication protocols, that can be applied to other problems as well.
11 citations
10 Sep 1990
TL;DR: A new deadlock free routing function which avoids the drawbacks of existing methods based on buffers ordering is proposed which is based on a protocol which insures the correct delivery of messages at their destination in networks of even degree.
Abstract: The purpose of this paper is to describe the theory behind a correct routing function suitable for parallel machines composed of networks of asynchronous processors. We propose a new deadlock free routing function which avoids the drawbacks of existing methods based on buffers ordering. The algorithm is based on a protocol which insures the correct delivery of messages at their destination in networks of even degree. A few restrictions are considered for the calculus of routes in the network. Under such restrictions, messages are routed through the shortest paths and never cross the same route. The buffer space required is independent of the size of the network. The routing function gives all the valid paths between any two nodes, thus adaptive routing can be envisaged in order to achieve load balancing.
9 citations
01 Apr 1990
TL;DR: A new adaptive flow control algorithm together with learning routing algorithms based on delay measurements that shows the superiority of the new scheme over existing algorithms.
Abstract: We present a new adaptive flow control algorithm together with learning routing algorithms.The key performance measure in both algorithms is packet delay. Window adjustment and route selection are based on delay measurements. Simulation results have shown the superiority of the new scheme over existing algorithms.
TL;DR: A multiorder routing strategy is developed which is loop-free even in the presence of link/node failures and a systematic procedure for striking a compromise between the operational overhead and network adaptability is proposed.
Abstract: A multiorder routing strategy is developed which is loop-free even in the presence of link/node failures. Unlike most conventional methods in which the same routing strategy is applied indiscriminately to all nodes in the network, nodes under this proposal may adopt different routing strategies according to the network structure. Formulas are developed to determine the minimal order of routing strategy for each node to eliminate looping completely. A systematic procedure for striking a compromise between the operational overhead and network adaptability is proposed. Several illustrative examples are presented. >
02 Dec 1990
TL;DR: A link status routing algorithm required each node to know the current status of all the links in the network, but the authors describe a link status update protocol designed for a highspeed network that uses the best-effort model of packet delivery, but is fault-tolerant.
Abstract: A link status routing algorithm required each node to know the current status of all the links in the network. Nodes use a link status update protocol that helps in keeping the database at each node up-to-date. The authors describe a link status update protocol designed for a highspeed network. The protocol uses the best-effort model of packet delivery, but is fault-tolerant. It uses an algorithm for fast propagation of link status updates that is optimized for the expected case when no update packets are lost, and no link or node failures occur. The protocol uses a separate mechanism to detect and recover from errors caused by loss of updates and failure of nodes or links. >
16 Apr 1990
TL;DR: An introduction to automatic integrated-circuit routing is presented, with particular attention given to the types of routing algorithm, global and detailed routing, and improving routing and routability.
Abstract: An introduction to automatic integrated-circuit routing is presented. Particular attention is given to the types of routing algorithm, global and detailed routing, and improving routing and routability. >
02 Dec 1990
TL;DR: It is shown that the source routing scheme outperforms the link-by-link routing in all of the following aspects: the call setup delay and capacity, the call looping probability, and the call denial rate.
Abstract: The author presents and comparatively analyzes the virtual-circuit routing control for the ISDN (integrated services digital network) frame-relay networks. The focus is on comparing the performance of the two routing control schemes: source routing and link-by-link routing. It is shown that the source routing scheme outperforms the link-by-link routing in all of the following aspects: the call setup delay and capacity, the call looping probability, and the call denial rate. It is thus recommended that the source routing control strategy with crankback mechanism be used for the ISDN frame-relay networks. >
01 Jan 1990
TL;DR: The routing phase follows the placement phase and determines the course of the wires that connect the cells laid out during the placement.
Abstract: The routing phase follows the placement phase. It determines the course of the wires that connect the cells laid out during the placement. The structure of the routing phase depends greatly on the design and fabrication technology. There are two approaches to routing—two-phase and area routing. In area routing, the routing process is carried out in one phase that determines the exact course of the wires. In two-phase routing the routing phase is subdivided into the global (or loose) routing phase—which determines how wires maneuver around and through cells—and the detailed (or local or homotopic) routing phase—which determines the exact course of the wires. We now describe both approaches to routing intuitively.
Proceedings Article•
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TL;DR: An alternative to minimum-cost routing control, called multiclass routing, is presented, followed by a discussion of special allowances of which the minimum-length criterion provides opportunities to take advantage.
Abstract: An alternative to minimum-cost routing control, called multiclass routing, is presented. Multiclass routing was developed as an extension to a suite of link and network protocols for a mobile-radio environment. These protocols were based on the design of a packet radio that uses spread spectrum whose parameters are controllable in real time. In particular, a link-control protocol takes advantage of these real-time-controllable parameters to establish optimal gains for use on links. Multiclass routing uses these link gains and other link quality measures in the first decision criterion in selecting routes. Minimum-length is the second criterion. The rules for multiclass route updating are presented, followed by a discussion of special allowances of which the minimum-length criterion provides opportunities to take advantage. A comprehensive comparison with the minimum-cost approach is then made. >
30 Sep 1990
TL;DR: A new bridge protocol for route determination in a multiple-ring network is introduced, its main advantage is its communication efficiency: the number of frames used is thenumber of rings plus the numberof bridges in the network, as opposed to the exponential function needed by the existing protocol.
Abstract: The issue of routing in multiple-ring networks is considered. A new bridge protocol for route determination in a multiple-ring network is introduced. Its main advantage is its communication efficiency: the number of frames used is the number of rings plus the number of bridges in the network, as opposed to the exponential function needed by the existing protocol. Some extensions of the protocol are given. The correctness proof for the new protocol is presented. >