Distributed Failure Restoration for Asynchronous Transfer Mode (ATM) Tactical Communication Networks

Asynchronous Transfer Mode (A TM) is an attractive choice for future military communication systems because it can provide high throughput and support multi-service applications. Furthermore its use is consistent with the 'off the shelf technology policy that is currently operated by the Defence Engineering Research Agency of Great Britain. However, A TM has been developed as a civil standard and is designed to operate in network infrastructures with very low failure rates. In contrast, tactical networks are much less reliable. Indeed tactical networks operate on the premise that failures, particularly node failures, are expected. Hence, efficient, automatic failure restoration schemes are essential if an A TM based tactical network is to remain operational. The main objective of this research is the proposal and verification of one or more new restoration algorithms that meet the specific requirements of tactical networks. The aspects of ATM networks that influence restoration algorithms' implementation are discussed. In particular, the features of A TM networks such as the concept of Virtual Paths Virtual Channels and OAM (Operation And Maintenance) mechanisms that facilitate implementation of efficient restoration techniques. The unique characteristics of tactical networks and their impact on restoration are also presented. A significant part of the research was the study and evaluation of existing approaches to failure restoration in civil networks. A critical analysis of the suitability of these approaches to the tactical environment shows no one restoration algorithm fully meets the requirements of tactical networks. Consequently, two restoration algorithms for tactical A TM networks, DRA-TN (Dynamic Restoration Algorithm for Tactical Networks) and PPR-TN (Pre-planned Restoration Algorithm for Tactical Networks), are proposed and described in detail. Since the primary concern of restoration in tactical networks is the recovery of high priority connections the proposed algorithms attempt to restore high-priority connections by disrupting low-priority calls. Also, a number of additional mechanisms are proposed to reduce the use of bandwidth, which is a scarce resource in tactical networks. It is next argued that software simulation is the most appropriate method to prove the consistency of the proposed algorithms, assess their performance and test them on different network topologies as well as traffic and failure conditions. For this reason a simulation software package was designed and built specifically to model the proposed restoration algorithms. The design of the package is presented in detail and the most important implementation issues are discussed. The proposed restoration algorithms are modelled on three network topologies under various traffic loads, and their performance compared against the performance of known algorithms proposed for civil networks. It is shown that DRA-TN and PPR-TN provide better restoration of higher priority traffic. Furthermore, as the traffic load increases the relative performance of the DRA-TN and PPR-TN algorithms increases. The DRA-TN and PPR-TN algorithms are also compared and their advantages and disadvantages noted. Also, recommendations are given about the applicability of the proposed algorithms, and some practical implementation issues are discussed. The number of problems that need further study are briefly described.Defence Engineering Research Agency of Great Britai

Design and implementation of a fault-tolerant multimedia network and a local map based (LMB) self-healing scheme for arbitrary topology networks.

by Arion Ko Kin Wa.Thesis (M.Phil.)--Chinese University of Hong Kong, 1997.Includes bibliographical references (leaves 101-[106]).Chapter 1 --- Introduction --- p.1Chapter 1.1 --- Overview --- p.1Chapter 1.2 --- Service Survivability Planning --- p.2Chapter 1.3 --- Categories of Outages --- p.3Chapter 1.4 --- Goals of Restoration --- p.4Chapter 1.5 --- Technology Impacts on Network Survivability --- p.5Chapter 1.6 --- Performance Models and Measures in Quantifying Network Sur- vivability --- p.6Chapter 1.7 --- Organization of Thesis --- p.6Chapter 2 --- Design and Implementation of A Survivable High-Speed Mul- timedia Network --- p.8Chapter 2.1 --- An Overview of CUM LAUDE NET --- p.8Chapter 2.2 --- The Network Architecture --- p.9Chapter 2.2.1 --- Architectural Overview --- p.9Chapter 2.2.2 --- Router-Node Design --- p.11Chapter 2.2.3 --- Buffer Allocation --- p.12Chapter 2.2.4 --- Buffer Transmission Priority --- p.14Chapter 2.2.5 --- Congestion Control --- p.15Chapter 2.3 --- Protocols --- p.16Chapter 2.3.1 --- Design Overview --- p.16Chapter 2.3.2 --- ACTA - The MAC Protocol --- p.17Chapter 2.3.3 --- Protocol Layering --- p.18Chapter 2.3.4 --- "Segment, Datagram and Packet Format" --- p.20Chapter 2.3.5 --- Fast Packet Routing --- p.22Chapter 2.3.6 --- Local Host NIU --- p.24Chapter 2.4 --- The Network Restoration Strategy --- p.25Chapter 2.4.1 --- The Dual-Ring Model and Assumptions --- p.26Chapter 2.4.2 --- Scenarios of Network Failure and Remedies --- p.26Chapter 2.4.3 --- Distributed Fault-Tolerant Algorithm --- p.26Chapter 2.4.4 --- Distributed Auto-Healing Algorithm --- p.28Chapter 2.4.5 --- The Network Management Signals --- p.31Chapter 2.5 --- Performance Evaluation --- p.32Chapter 2.5.1 --- Restoration Time --- p.32Chapter 2.5.2 --- Reliability Measures --- p.34Chapter 2.5.3 --- Network Availability During Restoration --- p.41Chapter 2.6 --- The Prototype --- p.42Chapter 2.7 --- Technical Problems Encountered --- p.45Chapter 2.8 --- Chapter Summary and Future Development --- p.46Chapter 3 --- A Simple Experimental Network Management Software - NET- MAN --- p.48Chapter 3.1 --- Introduction to NETMAN --- p.48Chapter 3.2 --- Network Management Basics --- p.49Chapter 3.2.1 --- The Level of Management Protocols --- p.49Chapter 3.2.2 --- Architecture Model --- p.51Chapter 3.2.3 --- TCP/IP Network Management Protocol Architecture --- p.53Chapter 3.2.4 --- A Standard Network Management Protocol On Internet - SNMP --- p.54Chapter 3.2.5 --- A Standard For Managed Information --- p.55Chapter 3.3 --- The CUM LAUDE Network Management Protocol Suite (CNMPS) --- p.56Chapter 3.3.1 --- The Architecture --- p.53Chapter 3.3.2 --- Goals of the CNMPS --- p.59Chapter 3.4 --- Highlights of NETMAN --- p.61Chapter 3.5 --- Functional Descriptions of NETMAN --- p.63Chapter 3.5.1 --- Topology Menu --- p.64Chapter 3.5.2 --- Fault Manager Menu --- p.65Chapter 3.5.3 --- Performance Meter Menu --- p.65Chapter 3.5.4 --- Gateway Utility Menu --- p.67Chapter 3.5.5 --- Tools Menu --- p.67Chapter 3.5.6 --- Help Menu --- p.68Chapter 3.6 --- Chapter Summary --- p.68Chapter 4 --- A Local Map Based (LMB) Self-Healing Scheme for Arbitrary Topology Networks --- p.70Chapter 4.1 --- Introduction --- p.79Chapter 4.2 --- An Overview of Existing DCS-Based Restoration Algorithms --- p.72Chapter 4.3 --- The Network Model and Assumptions --- p.74Chapter 4.4 --- Basics of the LMB Scheme --- p.75Chapter 4.4.1 --- Restoration Concepts --- p.75Chapter 4.4.2 --- Terminology --- p.76Chapter 4.4.3 --- Algorithm Parameters --- p.77Chapter 4.5 --- Performance Assessments --- p.78Chapter 4.6 --- The LMB Network Restoration Scheme --- p.80Chapter 4.6.1 --- Initialization - Local Map Building --- p.80Chapter 4.6.2 --- The LMB Restoration Messages Set --- p.81Chapter 4.6.3 --- Phase I - Local Map Update Phase --- p.81Chapter 4.6.4 --- Phase II - Update Acknowledgment Phase --- p.82Chapter 4.6.5 --- Phase III - Restoration and Confirmation Phase --- p.83Chapter 4.6.6 --- Phase IV - Cancellation Phase --- p.83Chapter 4.6.7 --- Re-Initialization --- p.84Chapter 4.6.8 --- Path Route Monitoring --- p.84Chapter 4.7 --- Performance Evaluation --- p.84Chapter 4.7.1 --- The Testbeds --- p.84Chapter 4.7.2 --- Simulation Results --- p.86Chapter 4.7.3 --- Storage Requirements --- p.89Chapter 4.8 --- The LMB Scheme on ATM and SONET environment --- p.92Chapter 4.9 --- Future Work --- p.94Chapter 4.10 --- Chapter Summary --- p.94Chapter 5 --- Conclusion and Future Work --- p.96Chapter 5.1 --- Conclusion --- p.95Chapter 5.2 --- Future Work --- p.99Bibliography --- p.101Chapter A --- Derivation of Communicative Probability --- p.107Chapter B --- List of Publications --- p.11

Protection and restoration algorithms for WDM optical networks

Currently, Wavelength Division Multiplexing (WDM) optical networks play a major role in supporting the outbreak in demand for high bandwidth networks driven by the Internet. It can be a catastrophe to millions of users if a single optical fiber is somehow cut off from the network, and there is no protection in the design of the logical topology for a restorative mechanism. Many protection and restoration algorithms are needed to prevent, reroute, and/or reconfigure the network from damages in such a situation. In the past few years, many works dealing with these issues have been reported. Those algorithms can be implemented in many ways with several different objective functions such as a minimization of protection path lengths, a minimization of restoration times, a maximization of restored bandwidths, etc. This thesis investigates, analyzes and compares the algorithms that are mainly aimed to guarantee or maximize the amount of remaining bandwidth still working over a damaged network. The parameters considered in this thesis are the routing computation and implementation mechanism, routing characteristics, recovering computation timing, network capacity assignment, and implementing layer. Performance analysis in terms of the restoration efficiency, the hop length, the percentage of bandwidth guaranteed, the network capacity utilization, and the blocking probability is conducted and evaluated

Design of survivable WDM network based on pre-configured protection cycle

Wavelength Division Multiplexing (WDM) is an important technique which allows the trans- port of large quantities of data over optical networks. All optical WDM-based networks have been used to improve overall communication capacity and provide an excellent choice for the design of backbone networks. However, due to the high traffic load that each link can carry in a WDM network, survivability against failures becomes very important. Survivability in this context is the ability of the network to maintain continuity of service against failures, since a failure can lead to huge data losses. In recent years, many survivability mechanisms have been studied and their performance assessed through capacity efficiency, restoration time and restorability. Survivability mechanisms for ring and mesh topologies have received particular attention

A high speed fault-tolerant multimedia network and connectionless gateway for ATM networks.

by Patrick Lam Sze Fan.Thesis (M.Phil.)--Chinese University of Hong Kong, 1997.Includes bibliographical references (leaves 163-[170]).Chapter 1 --- Introduction --- p.1Chapter 2 --- Fault-tolerant CUM LAUDE NET --- p.7Chapter 2.1 --- Overview of CUM LAUDE NET --- p.7Chapter 2.2 --- Network architecture of CUM LAUDE NET --- p.8Chapter 2.3 --- Design of Router-node --- p.10Chapter 2.3.1 --- Architecture of the Router-node --- p.10Chapter 2.3.2 --- Buffers Arrangement of the Router-node --- p.12Chapter 2.3.3 --- Buffer transmission policies --- p.13Chapter 2.4 --- Protocols of CUM LAUDE NET --- p.14Chapter 2.5 --- Frame Format of CUM LAUDE NET --- p.15Chapter 2.6 --- Fault-tolerant (FT) and Auto-healing (AH) algorithms --- p.16Chapter 2.6.1 --- Overview of the algorithms --- p.16Chapter 2.6.2 --- Network Failure Scenarios --- p.18Chapter 2.6.3 --- Design and Implementation of the Fault Tolerant Algorithm --- p.19Chapter 2.6.4 --- Design and Implementation of the Auto Healing Algorithm --- p.26Chapter 2.6.5 --- Network Management Signals and Restoration Times --- p.27Chapter 2.6.6 --- Comparison of fault-tolerance features of other networks with the CUM LAUDE NET --- p.31Chapter 2.7 --- Chapter Summary --- p.31Chapter 3 --- Overview of the Asynchronous Transfer Mode (ATM) --- p.33Chapter 3.1 --- Introduction --- p.33Chapter 3.2 --- ATM Network Interfaces --- p.34Chapter 3.3 --- ATM Virtual Connections --- p.35Chapter 3.4 --- ATM Cell Format --- p.36Chapter 3.5 --- ATM Address Formats --- p.36Chapter 3.6 --- ATM Protocol Reference Model --- p.38Chapter 3.6.1 --- The ATM Layer --- p.39Chapter 3.6.2 --- The ATM Adaptation Layer --- p.39Chapter 3.7 --- ATM Signalling --- p.44Chapter 3.7.1 --- ATM Signalling Messages and Call Setup Procedures --- p.45Chapter 3.8 --- Interim Local Management Interface (ILMI) --- p.47Chapter 4 --- Issues of Connectionless Gateway --- p.49Chapter 4.1 --- Introduction --- p.49Chapter 4.2 --- The Issues --- p.50Chapter 4.3 --- ATM Internetworking --- p.51Chapter 4.3.1 --- LAN Emulation --- p.52Chapter 4.3.2 --- IP over ATM --- p.53Chapter 4.3.3 --- Comparing IP over ATM and LAN Emulation --- p.59Chapter 4.4 --- Connection Management --- p.61Chapter 4.4.1 --- The Indirect Approach --- p.62Chapter 4.4.2 --- The Direct Approach --- p.63Chapter 4.4.3 --- Comparing the two approaches --- p.64Chapter 4.5 --- Protocol Conversion --- p.65Chapter 4.5.1 --- Selection of Protocol Converter --- p.68Chapter 4.6 --- Packet Forwarding Modes --- p.68Chapter 4.7 --- Bandwidth Assignment --- p.70Chapter 4.7.1 --- Bandwidth Reservation --- p.71Chapter 4.7.2 --- Fast Bandwidth Reservation --- p.72Chapter 4.7.3 --- Bandwidth Advertising --- p.72Chapter 4.7.4 --- Bandwidth Advertising with Cell Drop Detection --- p.73Chapter 4.7.5 --- Bandwidth Allocation on Source Demand --- p.73Chapter 4.7.6 --- The Common Problems --- p.74Chapter 5 --- Design and Implementation of the Connectionless Gateway --- p.77Chapter 5.1 --- Introduction --- p.77Chapter 5.1.1 --- Functions Definition of Connectionless Gateway --- p.79Chapter 5.2 --- Hardware Architecture of the Connectionless Gateway --- p.79Chapter 5.2.1 --- Imposed Limitations --- p.82Chapter 5.3 --- Software Architecture of the Connectionless Gateway --- p.83Chapter 5.3.1 --- TCP/IP Internals --- p.84Chapter 5.3.2 --- ATM on Linux --- p.85Chapter 5.4 --- Network Architecture --- p.88Chapter 5.4.1 --- IP Addresses Assignment --- p.90Chapter 5.5 --- Internal Structure of Connectionless Gateway --- p.90Chapter 5.5.1 --- Protocol Stacks of the Gateway --- p.90Chapter 5.5.2 --- Gateway Operation by Example --- p.93Chapter 5.5.3 --- Routing Table Maintenance --- p.97Chapter 5.6 --- Additional Features --- p.105Chapter 5.6.1 --- Priority Output Queues System --- p.105Chapter 5.6.2 --- Gateway Performance Monitor --- p.112Chapter 5.7 --- Setup an Operational ATM LAN --- p.117Chapter 5.7.1 --- SVC Connections --- p.117Chapter 5.7.2 --- PVC Connections --- p.119Chapter 5.8 --- Application of the Connectionless Gateway --- p.120Chapter 6 --- Performance Measurement of the Connectionless Gateway --- p.121Chapter 6.1 --- Introduction --- p.121Chapter 6.2 --- Experimental Setup --- p.121Chapter 6.3 --- Measurement Tools of the Experiments --- p.123Chapter 6.4 --- Descriptions of the Experiments --- p.124Chapter 6.4.1 --- Log Files --- p.125Chapter 6.5 --- UDP Control Rate Test --- p.126Chapter 6.5.1 --- Results and analysis of the UDP Control Rate Test --- p.127Chapter 6.6 --- UDP Maximum Rate Test --- p.138Chapter 6.6.1 --- Results and analysis of the UDP Maximum Rate Test --- p.138Chapter 6.7 --- TCP Maximum Rate Test --- p.140Chapter 6.7.1 --- Results and analysis of the TCP Maximum Rate Test --- p.140Chapter 6.8 --- Request/Response Test --- p.144Chapter 6.8.1 --- Results and analysis of the Request/Response Test --- p.144Chapter 6.9 --- Priority Queue System Verification Test --- p.149Chapter 6.9.1 --- Results and analysis of the Priority Queue System Verifi- cation Test --- p.150Chapter 6.10 --- Other Observations --- p.153Chapter 6.11 --- Solutions to Improve the Performance --- p.154Chapter 6.12 --- Future Development --- p.157Chapter 7 --- Conclusion --- p.158Bibliography --- p.163A List of Publications --- p.17

Applications of satellite technology to broadband ISDN networks

Two satellite architectures for delivering broadband integrated services digital network (B-ISDN) service are evaluated. The first is assumed integral to an existing terrestrial network, and provides complementary services such as interconnects to remote nodes as well as high-rate multicast and broadcast service. The interconnects are at a 155 Mbs rate and are shown as being met with a nonregenerative multibeam satellite having 10-1.5 degree spots. The second satellite architecture focuses on providing private B-ISDN networks as well as acting as a gateway to the public network. This is conceived as being provided by a regenerative multibeam satellite with on-board ATM (asynchronous transfer mode) processing payload. With up to 800 Mbs offered, higher satellite EIRP is required. This is accomplished with 12-0.4 degree hopping beams, covering a total of 110 dwell positions. It is estimated the space segment capital cost for architecture one would be about $190M whereas the second architecture would be about$250M. The net user cost is given for a variety of scenarios, but the cost for 155 Mbs services is shown to be about $15-22/minute for 25 percent system utilization

Survivable network design with stepwise incremental cost function

Modern society has become more and more dependent on information services, transferred in both public and private network, than ever before. The use of integration of computers with telecommunications has created a so-called “Information Age”. The advent of high capacity digital telecommunication facilities has made it possible for the huge amount of traffic to be carried in an economical and efficient method, in recent years. These facilities, which are used to carry much higher capacities than the traditional ones, also result in the network’s vulnerability to the failure of network facilities, i.e. a single link failure. This thesis is concerned with the technology by which the spare capacity on the link of mesh networks is placed in order to protect the active traffic from network failure with a minimal cost. Although there have been many works to address the issue all of these works have been developed based on the assumption that the link cost with its capacity is linear. In fact, the linear cost functions does not reflect the reality that optic fiber cables with the specific amount of capacities are only available, in other words, the link cost function is stepwise rather than linear. Therefore, all existing algorithms developed for the linear assumption may not be applicable properly for the stepwise case. A novel heuristic algorithm is proposed to solve the problem in this thesis. The algorithm is composed of two parts as follows. In part one, a maximum flow algorithm is employed to work out the maximal amount of feasible spare paths consisting of spare capacities in the network to re-route the disrupted traffic at the event of network failure. In part two, a newly proposed algorithm is used to find an alternative path on which to place the non-rerouted traffic on the failed link with the minimum network cost increment. The superiority of the algorithm is presented over other algorithms published in this area

Feasibility of wireless mesh for LTE-Advanced small cell access backhaul

Mobiilidatan määrä on muutaman viime vuoden aikana kasvanut voimakkaasti ja nykyiset ennustukset arvioivat eksponentiaalista kasvukäyrää tulevien vuosien aikana. Matkapuhelinjärjestelmät ovat kehittyneet nopeasti tämän trendin ohjaamana. Neljännen sukupolven matkapuhelinverkkostandardien myötä, uudet innovaatiot kuten heterogeeniset verkkoratkaisut tarjoavat ratkaisun nykyisiin skaalautuvuus- ja kapasiteettiongelmiin. Joitain ilmeisiä ongelmakohtiakin kuitenkin esiintyy kuten heterogeenisten verkkojen runkokytkennän toteuttaminen. Yksi lupaavimmista tavoista toteuttaa heterogeenisten verkkojen runkokytkentä on langaton ja itseorganisoituva mesh-verkko. Tämän opinnäytetyön tavoitteena on varmistaa ja testata Nokia Siemens Networksin kehittämän mesh-runkokytkentäverkkokonseptin toteutettavuutta ja toiminnallisuutta soveltuvan validointijärjestelmän avulla. Kaiken kaikkiaan validointijärjestelmä ja sen päälle toteutettu mesh-protokolla toimivat moitteettomasti koko kehitys- ja testausprosessin ajan. Konseptin eri ominaisuudet ja mekanismit todistettiin täysin toteutettaviksi ja toimiviksi. Muutamalla lisäominaisuudella ja konseptiparannuksella mesh-konsepti tarjoaa houkuttelevan ja innovatiivisen ratkaisun heterogeenisten verkkojen runkokytkentään tulevaisuudessa.Mobile traffic demands and volumes are increasing and will dramatically keep increasing in the future. Along with this, mobile networks have evolved to better match this growth. Fourth generation cellular network standard introduced a set of new innovations for mobile communications, including support for heterogeneous network deployments. Heterogeneous networking is the likely answer for future mobile data capacity shortage but also poses some challenges, the most evident being how to implement the backhauling. One of the most promising heterogeneous network backhaul solutions is a meshed radio system with self-organizing features. The main scope of this master's thesis is the verification of functionality and feasibility of a wireless mesh backhaul concept developed by Nokia Siemens Networks through a proof-of-concept system. All in all, the wireless mesh proof-of-concept system performed strongly throughout the development and testing process. The different functionalities were proven to work successfully together. With further development and enhancement, the system concept displays extreme potential for a state-of-the-art heterogeneous network backhaul technology