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Configuration management is critical to correct and efficient operation of large networks. Where the users and networks are dynamic and ad hoc, manual configuration quickly becomes too complex. The combination of the sheer number of nodes with heterogeneity and dynamics makes it almost impossible for the system administrator to ensure good configuration or even correct operation. To achieve the vision of pervasive computing, nodes must automatically discover their environment and self-configure, then automatically reconfigure to adapt to changes. Protocols such as DHCP, DDNS, and mDNS provide some degree of host autoconfiguration, but network administrators must still configure information such as address pools, routing protocols, and OSPF routing areas. Only limited progress has been made in automating the configuration of routers, servers, and network topology. We propose the first unified attempt to combine both self-configuration of much of the host, router, and server information with automatic generation and maintenance of hierarchy under the same algorithmic framework. Testbed implementations show the approach is practical, while simulations reveal its scalability, rapidity, and efficiency with respect to network performance. [ABSTRACT FROM AUTHOR]

MPLS is currently used by several ISPs to carry some high-value traffic components, such as telephony over if trunks and VPNs. For this type of traffic, service availability is a critical QoS dimension that needs to be protected from network failures. With MPLS-TE, this can be achieved by means of path protection schemes, where active and backup LSPs are routed along diverse paths. Resides protection, path diversity can be exploited for load balancing, another common means of QoS improvement. In order to preserve other QoS requirements, the paths must meet certain constraints (e.g., bandwidth availability, low load) and/or minimize some metric (e.g., hop count). This requires the ability to establish path diversity in an optimal way. In many cases of practical interest, the QoS traffic has an interdomain scope. This is the case for ToIP and VPN traffic between different carriers, or between different ASs owned by the same carrier, as found, for example, after corporate acquisitions or mergers. Therefore, path diversity is a requirement for interdomain traffic engineering. In this work we address path diversity in a multidomain network, where individual domains are capable of connection-oriented for-warding and endowed with an MPLS-TE control plane. For administrative and/or scalability reasons intradomain routing information is not disseminated externally, so dynamic path computation must be achieved by a distributed scheme based on interdomain collaboration. We briefly describe three alternative schemes recently proposed for interdomain diverse path computation, and quantitatively assess their performance with simulations over real ISP topologies. [ABSTRACT FROM AUTHOR]

With the worldwide success of IP-MPLS [1] networks deployment, inter-connecting multiple provider IP-MPLS networks for global teachability becomes the next important step. Many providers have implemented MPLS interprovider connections. In this article we first briefly describe the drivers behind the need of interprovider IP-MPLS services, such as layer 3 VPNs [2], pseudowire emulation for transporting layer 2 traffic over IP-MPLS, VoIP, and others. We then discuss the general requirements for the interconnections, from end users' and service providers' perspectives, including security, scalability, manageability, QoS, and end-to- end SLAs. We then address the deployment options and challenges faced by service providers. Specifically, we discuss the following areas of interprovider service implementation: protocol implementation options for L3 VPN and their trade-offs, methods for guaranteeing consistent QoS across providers' boundaries, interprovider traffic engineering approaches, and operation challenges: from business to processes, from troubleshooting/monitoring to SLAs. By identifying the issues and challenges, our ultimate goal is to move toward the development of much needed common practices and procedures to assist in the establishment of interprovider IP-MPLS services. [ABSTRACT FROM AUTHOR]

XML technology is penetrating network management in the IETF, UPnP, and DSL Forum suite of standards and protocols. The advantages of XML are offered at the cost of long byte streams due to XML's inherently verbose nature, The increase in packet size for remote configuration and management can pose problems, if executed in a point-to-multipoint arrangement comprising one automatic configuration server and thousands of home gateways and multimedia devices. We investigate and exploit the repetitive nature of text patterns in typical XML documents as produced by the configuration and management tasks and as coded in SOAP RPCs. The solution mainly comes from application of the Lempel-Ziv compression algorithm, with minimal additions in the proposed DSL Forum standard. Numerical and experimental results support the applicability and advantages of the proposed approach and provide insight on how these are attributable to different layers of the employed protocol stack. [ABSTRACT FROM AUTHOR]

Network direct attached storage (NDAS) is a network storage architecture that allows direct attachment of existing ATA/ATAPI devices to Ethernet without a separate server. Unlike other architectures such as NAS, SAN, and USB mass storage, no server computer intervenes between the storage and the client hosts. We describe an NDAS disk controller (ND C) amenable to lowcost single-chip implementation that processes a simplified L3/L4 protocol and converts commands between ATA/ATAPI and Ethernet, while the remaining complex tasks are performed by remote hosts. Unlike NAS architectures that use TCP/IP, NDAS uses a TCP-like lean protocol that lends itself well to high-performance hardware realization. Thanks to the simple NDAS architecture and protocol, an NDC implemented on a single 4 mm × 4 mm chip in 0.18 μm CMOS technology achieves a maximum throughput of 55 Mbytes/s on Gigabit Ethernet, which is comparable to that of a high-performance disk locally attached to a host computer. [ABSTRACT FROM AUTHOR]

Ongoing technological advances in portable devices, coupled with the need for continuous connectivity while mobile, have made ad hoc networks a compelling research and development topic, particularly in a challenging multimedia multihop scenario. The ability of IEEE 802.11's ad hoc mode of operation, as a dominating wireless local area network (WLAN) protocol, to serve multihop networks requires thorough investigation. In this article, through considering crucial real-life physical phenomena and avoiding as many confining assumptions as possible, system performance measures such as delay and packet failure rate are evaluated. As a result, the importance of adequate selection of the system parameters toward performance improvement is underscored. Moreover, the simulation results imply that by complementing through priority provisions, coordination, route reservation, clustering, and optimum channel coding considerations, the IEEE 802.11 medium access control (MAC) protocol can survive in a multihop scenario. The custom simulation environment developed features modularity, comprising traffic generator, mobility, wireless channel, and IEEE 802.11 protocol modules, and is capable of accommodating many more of the physical phenomena involved. [ABSTRACT FROM AUTHOR]

We present guidelines on how to design network layer protocols when the unit disk graph (UDG) model is replaced by a more realistic physical layer model. Instead of merely using the transmission radius in the UDG model, physical, MAC, and network layers share the information about a bit and/or packet reception probability as a function of distance between nodes. We assume that all nodes use the same transmission power for sending messages, and that a packet is received when all its bits are correctly received. The MAC layer reacts to this correctly received. The MAC layer reacts to this probabilistic reception information by adjusting the number of acknowledgments and/or retransmissions. We observe that an optimal route discovery protocol cannot be based on a single retransmission by each node, because such a search may fail to reach the destination or find the optimal path. Next, we discuss that gaining neighbor knowledge information with "hello" packets is not a trivial protocol. We describe localized position-based routing protocols that aim to minimize the expected hop count (incase of hop-by-hop acknowledgments and fixed bit rate) or maximize the probability od delivery (when acknowledgments are not sent). We propose a guideline for the design of greedy position-based routing protocols with known destination locations. The node currently holding the message will forward it to a neighbor (closer to the destination than itself) that minimizes the ratio of cost over progress, where the metrics used, while the progress measures the difference in distances to the destination. We consider two basic medium access layer approaches, with fixed and variable packet lengths. This article will serve as a preliminary contribution toward the development of network layer protocols that will match the assumptions and criteria already used in simulators and ultimately in real equipment. [ABSTRACT FROM AUTHOR]

The Internet provides a platform for rapid and timely in formation exchange among a disparate array of clients and servers. TCP and IP are separately designed and closely tied protocols that define the rules of communication between end hosts, and are the most commonly used protocol suite for data transfer in the Internet. The combination of TCPIIP dominates today's communication in various networks from the wired backbone to the heterogeneous network due to its remarkable simplicity and reliability. TCP has become the de facto standard used in most applications ranging from interactive sessions such as Telnet and HTTP, to bulk data transfer like FTP. TCP was originally designed primarily for wired networks. In a wired network, random bit error rate, a characteristic usually more pronounced in the wireless network, is negligible, and congestion is the main cause of packet loss. The emerging wireless applications, especially high-speed multimedia services and the advent of wireless IP communications carried by the Internet, call for calibration and sophisticated enhancement or modifications of this protocol suite for improved performance. Based on the assumption that packet losses are signals of network congestion, the additive increase multiplicative decrease congestion control of the stan- dard TCP protocol reaches the steady state, which reflects the protocol's efficiency in terms of throughput and link utilization. However, this assumption does not hold when the end-to-end path also includes wireless links. Factors such as high BER, unstable channel characteristics, and user mobility may all contribute to packet losses. Many studies have shown that the unmodified standard TCP performs poorly in a wireless environment due to its inability to distinguish packet losses caused by network congestion from those attributed to transmission errors. In this article, following a brief introduction to TCP, we analyze the problems TCP exhibits in the wireless IP communication environment, and illustrate viable solutions by detailed examples. [ABSTRACT FROM AUTHOR]

The group addressing model currently employed for supporting IP multicast has caused several implementation issues including global unique address allocation, sender admission control, and multicast forwarding state scalability. In this article we first review related work carried out to address these issues using different mechanisms and at different levels. We discuss their merits and deficiencies and also their possible combinations for improved performance. We then devise a protocol that works by introducing the idea of recursive unicast into an existing multicast routing protocol, inulticast extension to OSPF (MOSPF), to achieve scalable multicast. Simulation results are used to demonstrate the high performance of the devised protocol in reducing computational overhead and forwarding state at routers and also in easing address allocation and admission control. [ABSTRACT FROM AUTHOR]

Traffic engineering enhances an ISP's capability to manage and utilize its resources effectively. MPLS has emerged as an efficient packet forwarding tool that gives a significant boost to the traffic engineering capabilities of an ISP. A fundamental problem in MPLS is to reduce label space usage by label switched paths while meeting the requirements of the flows traversing the network. Using multipoint-to-point LSP trees has been proposed as one of the techniques to reduce label space usage. We look at the problem of creating multipoint-to-point LSPs given a set of precomputed point-to-point LSPs. We propose a heuristic for multipoint-to-point LSP creation and show its effectiveness. [ABSTRACT FROM AUTHOR]

This article describes a recent R&D result in supporting secure and dynamic coalition inter-networking scenarios, where a number of military and civil subnetworks are combined using IPsec in a higher-level IP secure military network. It is part of the work undertaken in the VPN Workshop initiative, where a set of national defense and research organizations are meeting together to align their vision and requirements on what an IPv4 or IPv6 secure and dynamic IPsec-based virtual private network should be, and how to deploy it in an international multidomain scenario. [ABSTRACT FROM AUTHOR]

IPv6 extends capabilities of legacy IPv4 networks. The advantages of IPv6, however, come at the cost of increased operational overhead. As government networks providing services to the global information grid (GIG) migrate toward an IPv6-based infrastructure, the implications of an expanded packet header must be analyzed. This article describes two IPv6 applicable header compression schemes developed by the IETF, and how networks across the GIG infrastructure can adopt them in an effort to reduce IPv6 expanded overhead requirements. [ABSTRACT FROM AUTHOR]

In the migration toward network-centric warfare, the NATO STANAG 4406 for Military Message Handling Systems (MMHS) may be used for direct information exchange between high-data-rate strategic users and low-data-rate tactical users by utilizing its new tactical protocol profile. In this article the protocol profiles are tested across a "worst case" tactical HF link providing IP services. There are considerable throughput gains available using the tactical pro- file. Among the various automated HF technologies tested, the new HDL+ data link protocol, suggested for standardization within NATO, shows the best throughput capabilities for short to medium-size messages on typical HF channels. 3G HF is the most robust technology at low signal-to-noise ratios. The 2G HF throughput performance suffers from inefficient linking procedures. There are optimization issues at different levels of the protocol stack, and implementation choices have great impact on overall performance. [ABSTRACT FROM AUTHOR]

In this article an automated manager called Traffic Engineering Automated Manager (TEAM) for DiffServ/MPLS networks is introduced, and its design and implementation details are discussed. TEAM is designed for complete automated management of an Internet domain. TEAM is an adaptive manager that provides the required quality of service to the users and reduces the congestion in the network. The former is achieved by reserving bandwidth resources for the requests and the latter by distributing the load efficiently. These goals are achieved by online measurements of the network state. TEAM is composed of a Traffic Engineering Tool (TET), which adaptively manages the bandwidth and routes in the network, a Measurement and Performance Evaluation Tool (MPET), which measures important parameters in the network and inputs them to the TET, and a Simulation Tool (ST), which may be used by TET to consolidate its decisions. These three tools work in synergy to achieve the desired network operation objectives. The experimental results demonstrate the efficiency of TEAM as a network manager in different and unpredictable traffic conditions at the expense of a limited increase in the computational complexity and costs. [ABSTRACT FROM AUTHOR]

Internetworking is a complex problem, traditionally tackled by splitting responsibilities between several layers of protocols arranged in a stack. A shortcoming of the current Internet suite's layers is that the responsibilities of individual layers are somewhat ill defined. The result is that frequently a feature may cause problems for higher layers when it unexpectedly exists lower in the stack, or may be unnecessarily and inefficiently implemented in multiple layers. Mobility is one such feature with no well defined place in classical protocol stacks. If a link layer hands over between two distinctly administered networks, a network layer protocol will likely need to acquire a new address. Similarly, if mobility is implemented at the network layer, such as with Mobile IP, transport layer protocols must be prepared to deal with a slew of problems (rapid changes in available capacity and delay, the asymmetry of triangle routes, and security policies, to name a few). Code for higher-level protocols (above transport) is less frequently reused, so higher-layer mobility schemes fail to leverage the large base of TCP sockets code. We discuss the various strengths and weaknesses of implementing mobility at three different layers of the protocol stack, concluding that a transport layer mobility scheme is likely to suit today's mobile Internet users best, and that ideally there should be more communication between layers to avoid conflict and inefficiency. [ABSTRACT FROM AUTHOR]

This article describes OAM in MPLS layer 2 transport networks. MPLS networks used to transport layer 2 traffic are referred to as MPLS layer 2 transport networks. They may be used to connect legacy layer 2 networks and/or provide layer 2 service to a user over a MPLS network. As legacy layer 2 networks migrate to use MPLS for transport, the role of MPLS OAM mechanisms is becoming increasingly important. This is because the converged network must offer the same OAM functionality as existing layer 2 networks. This article emphasizes the importance of end-to-end OAM, while emulating existing layer 2 services using MPLS transport. End-to-end fault detection is described in the context of various layer 2 over MPLS transport network models. The article focuses on state-of-the-art MPLS label switched path and pseudo wire OAM mechanisms being developed by the IETF. This includes fault detection and isolation mechanisms such as LSP-Ping, bidirectional forwarding detection, and virtual circuit connectivity verification. The applicability of each of these mechanisms is given. In some cases it may be possible to carry layer 2 OAM cells end-to-end, while in other cases this may not be possible. The relationship between segment-based OAM mechanisms and end-to-end OAM is described for each of these cases. [ABSTRACT FROM AUTHOR]

In the last few years, multiprotocol label switching has been successfully deployed by majority of service providers worldwide. The Label Distribution Protocol is used in many MPLS networks for distributing labels to establish the label switched paths. This article focuses on LDP failures, namely failures that may occur in LDP while the underlining Interior Gateway Protocol of choice, and the physical connections are operating normally. Since LDP and MPLS in general do not have intrinsic means for detecting these failures, new mechanisms have to be introduced to handle them. Furthermore, the IGP may remain unaware of the LDP failure, and continue to direct traffic to the faulty path. To resolve this situation, coupling between LDP and the routing protocol may have to be introduced. In this article, we discuss all aspects related to handling LDP failures: discovery, location, notification, recovery, and prevention. [ABSTRACT FROM AUTHOR]

New York City Transit's subway system is one of the largest and most complex mass transportation systems in the world. Because of the extensive subway system, an extensive communications network infrastructure is needed to allow for communications of the various subway services with the control centers to support mission-critical (and safety-critical) applications. The current network utilizes multilayer network technologies, including SONET, ATM, and IP (layer 2/3 device) layer networks. As a consequence of using these various technologies, extensive challenges are faced in trying to consolidate these separate networks into a single management view, simplifying (and automating) not only the provisioning aspects but also troubleshooting/ fault management aspects of the network. Such automation will help to simplify network operations and allow for better handling and management of the reliability and availability of the network. To achieve this goal, various technologies were evaluated. Consideration is being given to multiprotocol label switching technology. MPLS offers the potential to help converge to a simpler networking model. In order to achieve this, certain capabilities must be available (e.g., the ability to quickly and automatically identify defects/failures and subsequently reroute around these failures). This article discusses the operational requirements for the MPLS network from the point of view of backbone networks that support a mass transportation system operator. [ABSTRACT FROM AUTHOR]

This article provides an overview of AT&T's MPLS OAM architecture, and gives examples of operational experience. Hallmarks of the architecture are a single, converged, and integrated MPLS/optical network, and the evolution to fully automated, zero-touch network operation. The Concept of One converged IPIMPLS architecture will reduce operations, development, and capital costs. The Concept of Zero aims to bring full automation for every human-to-computer interaction currently required for setting up and maintaining network services, delivering services to customers in real time with zero defects and cycle time, and supporting both a network as well as an operational environment with six nines reliability. This approach effectively opens the network to the customer, enabling new levels of customer network management, service creation, and ordering, and empowering enterprise customers with the tools to create their own network services as they transform their own internal networks. In the article we describe AT&T's MPLS-enabled services, the corresponding MPLS operations architecture (including MPLS MIBs), our MPLS OAM operational experience, and MPLS OAM evolution needs for MPLS MIB enhancements and new network capabilities. By applying technologies such as artificial intelligence, self-healing/self-identifying network elements, expert systems, rules-based processes, and automatic speech recognition, the architecture will migrate from a predictive network that monitors, correlates, and recommends action; to an adaptive network that monitors, correlates, and takes action; to a cybernated network that has integrated components that dynamically manage by business rules and policies. We give several examples of how AT&T is already investing in and implementing this future vision, and conclude by challenging network researchers, developers, and key industry players to apply new technologies in fully realizing the operational vision. [ABSTRACT FROM AUTHOR]

The boundaries between packet and circuit networks have long disappeared, with many traditional circuit-switched applications such as voice and video now being carried over packet-switched IP/MPLS or Ethernet networks. However, this transition has happened so fast that many OAM functions supported by circuit-switched networks such as SONET/SDH are still unmatched in packet networks. In order to match the quality sustained by circuit-switched networks, OAM functions must also be developed for such packet networks. A number of recent efforts have started to address OAM functions for IP/MPLS and Ethernet packet technologies. Service providers and carriers alike are the driving force behind the work, as there is general recognition that to generate sustained revenues, services must be efficiently managed. In this article we discuss issues in providing OAM features and capabilities for MPLS-based packet networks. [ABSTRACT FROM AUTHOR]

Increasingly intelligent Internet overlay networks promise to deliver streaming media and value-added media services in ways that cannot be achieved easily with conventional broadcast networks. Such an overlay would allow an individual viewer or groups of viewers to receive unique programming content (e.g., commercial advertisements, entertainment) that matches their previously specified preferences. Toward this end, we introduce a scalable overlay network architecture and signaling mechanism that permits dynamic program insertions in live high-quality video streams transmitted over IP networks. We describe the implementation of an application proxy that dynamically inserts prerecorded video programs into NTSC D1 quality Motion-JPEG streams with no visible artifacts. We argue that on-demand program switching is merely a first step toward a new generation of media services; increases in computing power will ultimately permit network-based proxies to manipulate and augment multimedia content as it flows through the network. [ABSTRACT FROM AUTHOR]

The recent advent of converging the IP and optical networks has necessitated the development of a generalized multiprotocol label switch-in framework. Resilience becomes more important than ever before in a GMPLS network since a single cut of an optical fiber may generate hundreds of link and node failures at high layers of the GMPLS architecture. In this article we briefly survey the current work regarding GMPLS recovery management, and present a new resilience-based dynamic GMPLS path management strategy. We present a simple model to represent the resilience requirements in GMPLS path management, and propose fast path management algorithms. The salient feature of the proposed approach is that it enables the paths to be dynamically selected under multiple simultaneous failure occurrences while satisfying the resilience requirement. Backup path design rules are developed, and the condition for backup path availability is derived for the special mesh-type GMPLS network. Finally, a simple example is shown to illustrate the effectiveness of the proposed resilience model and path management mechanism. [ABSTRACT FROM AUTHOR]

We present an overview of scalable admission control in IP networks. We introduce various approaches and discuss the mechanism and characteristics of each method. In particular, we argue that end-to-end measurement based admission control (EMBAC), which employs end-to-end on-demand probing, should be used for call admission control. Second, we consider use of EMBAC in VoIP networks. We present a new probability-based EMBAC scheme and show that its performance is close to the ideal method using virtual-trunk-based admission control. We also present a QoS allocation approach for selecting an admission threshold and dimensioning link capacities. A simple network design and evaluation results suggest that this QoS allocation approach is effective to adequately dimension a network, while satisfying end-to-end targets in terms of blocking probability and packet loss rate. [ABSTRACT FROM AUTHOR]

Since quality is not generally guaranteed in an IP network, the proper design and management of networks and/or terminals for high-quality voice over IP services and maintenance of service levels is important. In terms of quality design and management, methodologies for appropriately and effectively evaluating the perceptual QoS of VoIP are indispensable. This article gives an overview of the state of the art of quality assessment technologies for VoIP, including recent work on improving their accuracy. [ABSTRACT FROM AUTHOR]

Virtual private network services are often classified by the OSI layer at which the VPN service provider's systems interchange VPN reachability information with customer sites. Layer 2 and 3 VPN services are currently being designed and deployed even as the related standards are being developed. This article describes the wide range of emerging L2 and L3 VPN architectures and technical solutions or approaches, and discusses the status of standards work. Some specific L2VPN and L3VPN technologies described here include virtual private LAN service, transparent LAN service, BGP/MPLS-based VPNs (RFC 2547bis), virtual router, and IPSec VPN approaches. We discuss recent and continuing standards efforts in the IETF 12vpn and 13vpn working groups, and related work in the Pseudo- Wire Emulation Edge-to-Edge working group, as well as in some other standards for a, and describe some mechanisms that provide membership, reachability, topology, security, and management functions. [ABSTRACT FROM AUTHOR]

In this article discuss QoS from a somewhat unconventional point of view. First of all. we argue that high availability is a key ingredient in the QoS perceived by the user. High availability with extremely short interruptions in case of failure is needed for acceptable QoS in real-time dialog services such as telephony or video conferencing. Second, an even distribution of the traffic load over the network is essential to ensure efficient network utilization given that some kind of admission control for QoS traffic has to be in place for overload avoidance. Unfortunately both these features are not adequately provided in current IP networks. We therefore introduce a new routing scheme offering a massive improvement in availability as well as efficient distribution, while causing only minor computational effort. Our proposals are then evaluated for a high speed core network. We claim that our proposed approach would be a useful basis for QoS services in an NGN. [ABSTRACT FROM AUTHOR]

The emerging next-generation networking environment presents an IP-based core interconnecting many wireless radio access networks, providing ubiquitous access to end users through a vast variety of wireless devices. Although the IP protocol will be the common denominator, the new environment brings together many different interconnecting domains, each following different QoS models, complicating the overall end-to-end QoS process. This article discusses the need to standardize an end-to-end QoS protocol. It does not, however, focus on the signaling mechanism, since there is currently a relevant ongoing activity in IETF. Instead, it concentrates on the formulation of the QoS information describing the QoS requirements of the session to be established. It presents the Generic Service Specification Framework that not only enables the QoS requirements of a specific session to be captured (like a generic QoS template), but also the QoS classes of each IP domain can be described according to it. Through the systematic specification of a domain's QoS classes, an intelligent automatic mapping algorithm can be applied during an end-to-end QoS request, in order to select the most appropriate service class in each domain, as well as to extract the required traffic-related parameters to perform traffic con- trol operations, such as admission control, policing, and scheduling. [ABSTRACT FROM AUTHOR]

We present a novel end-to-end QoS architecture that enables seamless services over heterogeneous wireless access networks. We discuss the main architectural approaches and design issues of mobility-aware QoS signaling in IP networks. then we introduces a QoS signaling architecture that integrates resource management. It is based on a domain resource manager concept and nicely supports various handover types in an integrated approach. In particular, we support anticipated handover with pre-reservation of resources over the old network before the mobile node is attached to the new access point. [ABSTRACT FROM AUTHOR]

Although anycast communication supports service-oriented addresses, many of its current definitions in IPv6 are unclear. Furthermore, since there are no protocol standards or even a consensus on controlling routing, intersegment anycast communications are not yet available. In this article we first review [Pv6-based anycast communication. At present, there are several possible applications that are suited to this. We then raise several problems and provide possible solutions to these. Based on this background, we present the Anycast Address Resolving Protocol (AARP) to establish TCP connections with a specific anycast address, and then propose a routing protocol for intersegment anycasts. Our proposed architecture makes anycast addresses more useful without (or with at most minimal) need for modifications/extensions to existing applications and/or upper-layer protocols. [ABSTRACT FROM AUTHOR]

The prevalent use of best-effort topology- driven IP routing protocols with shortest path calculations can often lead to serious imbalance of packet traffic distribution when least cost paths converge on the same set of links, leading to unacceptable delays or packet loss even in the presence of feasible paths over less utilized links. Recently proposed enhancements to common routing protocols are promising to overcome such shortcomings by providing the means to distribute link state information that is more pertinent to traffic engineering in routed networks. This article presents several key results on the performance of the recently proposed OSPF-TE, with particular emphasis on OSPF- It protocol traffic overhead and the impact of new link state advertisement triggering mechanisms on traffic-engineered routing accuracy. [ABSTRACT FROM AUTHOR]

Next-generation wireless systems should provide to the user access to a broad range of services in a transparent way, independent of user location by making the technology invisible and embedded in the natural surroundings. Reaching this goal requires efficient cooperation between heterogeneous networking technologies and different protocols. Wireless personal networks are an integral part of such an emerging heterogeneous infrastructure. It is highly desirable, and in fact required due to economical constraints, to incorporate the present wireless systems in building the new paradigm. The key "protocol glue" between systems is the use of IP. Based on this scenario, we describe an architecture suited for the present and future personal mobile communications networks and services. [ABSTRACT FROM AUTHOR]

The Stream Control Transmission Protocol (SCTP) is being standardized by the IETF as a reliable transport protocol to transport SS7 signaling messages over IP networks. Due to its attractive features such as multistreaming and multihoming, SCTP has received much attention from the network community, in terms of both research and development. This article introduces the main features of SCTP, and discusses the state of the art in SCTP research and development activities. We also provide a survey of the available products that use SCTP. Finally, with a view to stimulating further research in this area, the challenges faced by the SCTP research community are identified. [ABSTRACT FROM AUTHOR]

Several solutions are proposed to extend storage area networking solutions over distances of hundreds to thousands of kilometers. Native Fibre Channel or end-to-end Fibre-Channel-based solutions can be offered over long distances using SONET-based networks. Protocols such as Internet SCSI (iSCSI), Internet Fibre Channel Protocol (iFCP) and Fibre Channel over TCP-IP (PCIP) are being proposed to enable storage area networking solutions over networks that use IP as their transport protocol. Performance analysis of these solutions in terms of application throughput under variable network conditions of packet loss, bandwidth availability, extension distance, and TCP implementations in the sender and receiver is presented based on analytical modeling of different solutions. [ABSTRACT FROM AUTHOR]

Over the last decade, the tremendous growth in the mobile Internet user population has been accompanied by an equally exciting evolution in wireless data networks. However, quite understandably, the evolution has been distinctly characterized by an increasing degree of heterogeneity along several dimensions such as the access technology, network model, device, and application requirements. This heterogeneity, in turn, imposes a significant challenge on the design of the network protocol stack, and leads to the question: how can the protocol stack at a mobile host cater effectively to the heterogeneous characteristics of the operating environment? In this article we provide an overview of AdaptNet, an adaptive protocol suite for next-generation wireless data networks. AdaptNet consists of protocol solutions at different layers of the protocol stack addressing several problems, including rate adaptation, congestion control, mobility support, and coding. A common traderlying theme in the design of the protocols in the AdaptNet suite is adaptiveness to the operating environment. Through high-level discussions, preliminary results, and pointers to relevant related work, we show how AdaptNet achieves the goal of effectively addressing heterogeneity in next-generation wireless data networks. [ABSTRACT FROM AUTHOR]

SONET/SDH technologies constitute the core transport infrastructure of major telecom service providers worldwide. As the percentage of packet-oriented traffic in the overall traffic demand continues to rise, prompted by the widespread adoption of the Internet Protocol suite, and recently by the fast adoption of Ethernet services, there is increasing pressure to improve the service provider's transport infrastructure in ways that make it data-aware and cost-effective for packet-oriented applications. Steps in this direction include the adoption of native physical interfaces, for Ethernet and storage area networks as service interfaces, or full integration of packet switching capabilites from Ethernet, Resilient Packet Ring, and MPLS technologies. This article discusses the emerging building blocks for next-generation data-aware transport networks and next-generation transport network elements. [ABSTRACT FROM AUTHOR]

This article presents the deployment and test of IPv6 services in the very high broadband IP/WDM (VTHD) [1] network for new-generation Internet applications. The VTHD project is partially funded by the French government through the French Research Network for Telecom (RNRT). VTHD supports both IPv4 and IPv6 services, and interconnects research centers and institutions in France. It has a public autonomous system number (AS20603) and a public IPv6 subnet. It is connected to the IEv6 global network via Open Transit (France Telecom's international IP service for ISPs). VTHD in France compares with Internet2 in the United States. This article focuses on the implementation of the lPv6 service, IPv6 performance (in the context of a high-speed network), the advantages of given technologies, and problems encountered. The following items are developed: • VTHD architecture • IPv6 address space and aggregation • Transition mechanisms • Routing protocols • Network test performance • IPSec est performance • Naming (DNS) • Network management [ABSTRACT FROM AUTHOR]

Anycast is a new "one-to-one-of-many" communication method in IPv6 networks. With this technology, the problem of finding the best sewer to respond to a request becomes a virtual noop. Hindered by unresolved issues and the slow deployment of IPv6, network-layer anycast is still not a reality. However, an increase in interest and research surrounding anycast recently warrants a look at the state and direction of the ideas in this area. This article describes some of the major problems with network-layer anycast and their possible solutions, as well as some optimizations and applications that have been developed recently. [ABSTRACT FROM AUTHOR]

Many new Internet applications require data transmission from a sender to multiple receivers. Unfortunately, the IP multicast technology used today suffers from scalability problems, especially when used for small and sparse groups. Multicast for small conferences (MSC) is a novel approach aimed at providing more efficient support for audio conferences, for example. It makes use of an IPv6 routing header. The unicast addresses of a small receiver group are put into the extension header in order to be forwarded to all group members. The results indicate that MSC has the potential to replace IP multicast for many delay-sensitive small group applications, even with very limited support from the network infrastructure. [ABSTRACT FROM AUTHOR]

Third-generation cellular networks have been designed to provide a variety of IP data services. Both IPv4 and IPv6 are supported in order to provide future-proof solutions. Mobility is supported through both cellular-specific and IP mechanisms. Mobile IP is becoming a key technology for managing mobility wireless networks. At the same time, the Session Initiation Protocol is the key to realizing and provisioning services in IP-based cellular networks. The need for mobility of future real-time service independent of terminal mobility requires SIP to seamlessly interwork with Mobile IP operations. In this article we investigate the issues related to interworking between SIP and Mobile IP, with a focus on IPv6 and the applicability to 3G networks being standardized in 3GPP and 3GPP2. [ABSTRACT FROM AUTHOR]

IPv6 has been designed, among other things, to provide an expanded address space to satisfy the future networking requirements. In this article we analyze and discuss important aspects of IPv6 deployment scenarios, and propose the system architecture coexisting and integrating with IPv4/MPLS networks. We investigate on various IPv6 deployment strategies along with network design examples, Comparing these techniques. Then the IPv6 deployment in service provider environments is proposed. [ABSTRACT FROM AUTHOR]

Due to volatile market conditions and increased competition, network operators and Internet service providers have been put under enormous pressure to cut costs while providing the same if not better levels of service to customers. Several aspects of network design are subject to review to assess possible cost savings while maintaining service levels and reliability. This article focuses on Internet Protocol network infrastructure design, and in particular investigates architectural options for interconnecting small "IP metro" PoPs to an "IP core" PoP. The baseline architecture is characterized by dual uplink circuits from the metro to the core PoP. Three variants of an alternative architecture based on a single uplink circuit from the metro to the core PoP are compared against the baseline network in terms of end-to-end availability/downtime and capital cost. [ABSTRACT FROM AUTHOR]

The high demand for wireless Internet Connectivity has driven the development of highly efficient radio link technologies. However, their performance can be compromised by inadvertent interactions with the higher-layer TCP flow Control protocol. Maximizing the performance of wireless links requires that mechanisms operating at every layer of the protocol stack interact efficiently. This article provides a brief tutorial of some of these radio link enhancements. It then outlines how higher-layer flow control protocols should behave, and provides techniques for taming the behavior of TCP, to ensure that the performance of lower-layer enhancements is not compromised. [ABSTRACT FROM AUTHOR]

Analyzes pros and cons of providing Internet protocol (IP) multimedia session control capabilities of real-time IP multimedia services in universal mobile telecommunication system (UTMS), as opposed to just providing basic IP connectivity, as of November 3, 2003. Overview of IP multimedia services; Overview of the general packet radio services architecture; Advantages and disadvantages of providing only basic IP connectivity; Concepts of IP multimedia subsystems; Overview of control signaling for wireless-to-wireless session setup. INSET: UMTS RELEASES..

Provides a quantitative analysis of a Mobile IP, a computer network protocol, -based wireless local area network and general packet radio service (WLAN-GPRS) handover prototype that identifies a number of side-effects related to the link layer and routing mechanisms, and presents the impact of handover on user datagram protocol and transmission control protocol data traffic as well as on Mobile IP signaling itself, to addresses cross-access technology handover known as vertical handover in terrestrial radio access networks, as of November 3, 2003. Benefits of managing vertical handovers with Mobile IP; Overview of Mobile IP in WLAN-GPRS environment; Account of scenarios supported by Mobile IP; Quantitative approach to vertical handover.

Focuses on multiprotocol label switching (MPLS) protection methods. Utilization of the methods in combination with online routing methods; Pros and cons of several label switch path backup types; Relationship between MPLS fault management and quality of service online routing methods.

Describes the packet sequencing deterministic protocol for routing delay and loss-sensitive traffic through an Internet protocol (IP) network. Difference of the protocol from traditional approaches; Packet sequencing's use of a temporally-based deterministic protocol to coordinate and switch IP packets on a system-wide basis.

Presents a comprehensive techno-economic evaluation of two upgrade strategy cases for broadband Internet protocol services for residential and business customers. Description and characterization of the network areas considered; Application of the broadband forecast model for the urban service access area.

Details an architecture for Digital Subscriber Line access facilitating Internet Protocol service guarantees leveraging quality of service mechanisms in transport-technology-specific data plane. Details regarding the Enhanced Resource and Information Control architecture; Creation of an overlay network on a physical network.

Presents a critical retrospective on the author's vision on Internet Protocol-optical integration. Control plane architectures; Data framing; Performance monitoring; Resource provisioning.

Discusses the specifications and applications of the iSCI computer network protocol which is used to access storage devices. Features of the TCP/IP computer network protocol; iSCI protocol units; Methods for naming, discovery, security, data placement and recovery.