Showing papers on "Overlay network published in 2000"

Overcast: reliable multicasting with on overlay network

Abstract: Overcast is an application-level multicasting system that can be incrementally deployed using today's Internet infrastructure. These properties stem from Overcast's implementation as an overlay network. An overlay network consists of a collection of nodes placed at strategic locations in an existing network fabric. These nodes implement a network abstraction on top of the network provided by the underlying substrate network.Overcast provides scalable and reliable single-source multicast using a simple protocol for building efficient data distribution trees that adapt to changing network conditions. To support fast joins, Overcast implements a new protocol for efficiently tracking the global status of a changing distribution tree.Results based on simulations confirm that Overcast provides its added functionality while performing competitively with IP Multicast. Simulations indicate that Overcast quickly builds bandwidth-efficient distribution trees that, compared to IP Multicast, provide 70%-100% of the total bandwidth possible, at a cost of somewhat less than twice the network load. In addition, Overcast adapts quickly to changes caused by the addition of new nodes or the failure of existing nodes without causing undue load on the multicast source.

Centertrack: an IP overlay network for tracking DoS floods

Abstract: Finding the source of forged Internet Protocol (IP) datagrams in a large, high-speed network is difficult due to the design of the IP protocol and the lack of sufficient capability in most high-speed, high-capacity router implementations. Typically, not enough of the routers in such a network are capable of performing the packet forwarding diagnostics required for this. As a result, tracking-down the source of a flood-type denial-of-service (DoS) attack is usually difficult or impossible in these networks. CenterTrack is an overlay network, consisting of IP tunnels or other connections, that is used to selectively reroute interesting datagrams directly from edge routers to special tracking routers. The tracking routers, or associated sniffers, can easily determine the ingress edge router by observing from which tunnel the datagrams arrive. The datagrams can be examined, then dropped or forwarded to the appropriate egress point. This system simplifies the work required to determine the ingress adjacency of a flood attack while bypassing any equipment which may be incapable of performing the necessary diagnostic functions.

On-demand overlay routing for computer-based communication networks

Abstract: Methods and apparatus are disclosed for dynamically discovering and utilizing an optimized network path through overlay routing for the transmission of data. A determination whether to use a default network path or to instead use an alternate data forwarding path through one or more overlay nodes is based on real-time measurement of costs associated with the alternative paths, in response to a user request for transmission of message data to a destination on the network. Cost metrics include delay, throughput, jitter, loss, and security. The system chooses the best path among the default forwarding path and the multiple alternate forwarding paths, and implements appropriate control actions to force data transmission along the chosen path. No modification of established network communication protocols is required.

RMX: reliable multicast for heterogeneous networks

Abstract: Although IP multicast is an effective network primitive for best-effort, large-scale, multi-point communication, many multicast applications such as shared whiteboards, multi-player games and software distribution require reliable data delivery. Building services like reliable sequenced delivery on top of IP multicast has proven to be a hard problem. The enormous extent of network and end-system heterogeneity in multipoint communication exacerbates the design of scalable end-to-end reliable multicast protocols. In this paper, we propose a radical departure from the traditional end-to-end model for reliable multicast and instead propose a hybrid approach that leverages the successes of unicast reliability protocols such as TCP while retaining the efficiency of IP multicast for multi-point data delivery. Our approach splits a large heterogeneous reliable multicast session into a number of multicast data groups of co-located homogeneous participants. A collection of application-aware agents-reliable multicast proxies (RMX)-organizes these data groups into a spanning tree using an overlay network of TCP connections. Sources transmit data to their local group, and the RMX in that group forwards the data towards the rest of the data groups. RMX use detailed knowledge of application semantics to adapt to the effects of heterogeneity in the environment. To demonstrate the efficacy of our architecture, we have built a prototype implementation that can be customized for different kinds of applications.

IP over optical networks: architectural aspects

Abstract: The Internet transport infrastructure is moving toward a model of high-speed routers interconnected by intelligent optical core networks. A consensus is emerging in the industry on utilizing an IP-centric control plane within optical networks to support dynamic provisioning and restoration of lightpaths. At the same time, there are divergent views on how IP routers must interact with optical core networks to achieve end-to-end connectivity. This article describes the architectural alternatives for interconnecting IP routers over optical networks, considering the routing and signaling issues. Also, the application of IP-based protocols for dynamic provisioning and restoration of lightpaths, as well as the interworking of multivendor optical networks is described.

Architectural and technological issues for future optical Internet networks

Abstract: This article reports a review of the most significant issues related to network architectures and technologies which will enable the realization of future optical Internet networks. The design of such networks has to take into consideration the peculiar characteristics of Internet traffic. Several architectures have been proposed to provide optical networking solutions, based on wavelength-division multiplexing and compatible with the IP world. These architectures are presented briefly, and the main advantages and drawbacks are discussed. Furthermore, advanced network architectures are reported. In particular, two network paradigms are illustrated and discussed: the optical transparent packet network and optical burst switching. Finally, the key technologies are illustrated.

A low latency, loss tolerant architecture and protocol for wide area group communication

Abstract: Group communication systems are proven tools upon which to build fault-tolerant systems. As the demands for fault-tolerance increase and more applications require reliable distributed computing over wide area networks, wide area group communication systems are becoming very useful. However, building a wide area group communication system is a challenge. This paper presents the design of the transport protocols of the spread wide area group communication system. We focus on two aspects of the system. First, the value of using overlay networks for application level group communication services. Second, the requirements and design of effective low latency link protocols used to construct wide area group communication. We support our claims with the results of live experiments conducted over the Internet.

Virtual network generation system and method

Abstract: A virtual network generation system facilitates the dynamic establishment, maintenance and dissolution of private network communities (PNCs), which may include extended communication links between isolated and geographically dispersed wired and/or wireless electronic devices, as if the electronic devices were set in their own LAN. The virtual network generation system takes advantage of existing communication infrastructure, such as the Internet, Wide Area Networks (WANs), power-lines, telephone lines, and cable networks, and uses them as shared backbones providing dynamic PNC links. Electronic devices connected to the dynamic private network become virtual nodes relating to different PNCs.

Measurement and analysis of IP network usage and behavior

Abstract: Traffic, usage, and performance measurements are crucial to the design, operation and control of Internet protocol networks. This article describes a prototype infrastructure for the measurement, storage, and correlation of network data of different types and origins from AT&T's commercial IP network. We focus first on some novel aspects of the measurement infrastructure, then describe analyses that illustrate the power of joining different measured data sets for network planning and design.

Integrated method for performing scheduling, routing and access control in a computer network

Abstract: An integrated highly adaptive method is presented to perform scheduling, routing and access control in a network. The network is made up of a plurality of nodes interconnected by links between at least some of the nodes wherein at least one path interconnects all of the plurality of nodes. The nodes are organized into at least one of a cluster and a clique and the network has a network-wide capacity to send data packets in slots delineating time frames on the network between the nodes on the network defined by the links. The plurality of nodes can be configured to process at least one flow comprising at least a portion of a transmitted and received data packet for which the plurality of nodes must manage to get the data packets to a desired node on the network.

Quality of service in IP networks: foundations for a multi-service Internet

Abstract: Quality of Service is a fast growing area of technology, being driven by the growth of real-time applications such as voice over IP. This book is perfect for you, technical professionals who are looking for information building blocks of Quality of Service and who want to grasp critical concepts such as the DiffServ and IntServ models and the use of MPLS to support the next generation of VPNs. If you are a Network architect, network engineer, or network designer, you will be using the authoritative guide to understand the different emerging technologies that can be used to archive Quality of Service, and to decide how to incorporate them into your networks and meet the needs of your particular network environment. Quality of Service in IP Networks presents a great deal of technical detail, as well as provides a clear understanding of the architectural issues surrounding delivering QoS in an IP network, and its positions in the emerging technologies within a framework of solutions.

Establishing connections with a pre-specified quality of service across a communications network

Abstract: On receipt of a request for a communication session over a communications network, such as an Internet Protocol communications network, a method of establishing a path for this session which provides a guaranteed quality of service is described. In a preferred example the communications network is an MPLS network and the method uses a modified version of the SIP messaging protocol. A number of possible paths for the communication session are identified and ranked according to factors such as traffic levels. Bandwidth along a chosen path is reserved and a messaging protocol such as CR-LDP used to establish this reserved path for the communication session. An advertising mechanism is used to provide entities in the network with information about topology and traffic levels. This enables the ranks to be determined effectively. The communications network has an overlay network of high capacity paths established on it. By arranging for communication sessions to preferably be established using these pre-determined high capacity paths the complexity of the topology information required is reduced.

Active networks for efficient distributed network management

Abstract: The emerging next generation of routers exhibit both high performance and rich functionality, such as support for virtual private networks and QoS. To achieve this, per-flow queuing and fast IP filtering are incorporated into the router hardware. The management of a network comprising such devices and efficient use of the new functionality introduce new challenges. A truly distributed network management system is an attractive candidate to address these challenges. We describe how active network techniques can be used to allow fast and easy deployment of distributed network management applications in IP networks. We describe a prototype system where legacy routers are enhanced with an adjunct active engine, which enables the safe execution and rapid deployment of new distributed management applications in the network layer. This system can gradually be integrated in today's IP network, and allows smooth migration from IP to programmable networks. This is done with an emphasis on efficient use of network resources, which is somewhat obscure by many of today's high-level solutions.

Method for performing roaming amongst multiple IP networks

Abstract: A method of allowing subscribers of a computer network to roam among a plurality of networks. When the subscriber attempts to communicate from a network he is visiting, the visiting network server will communicate with the home network server to verify the authenticity of the subscriber. Once authentication is completed, the visiting server will issue a temporary visiting if address to the subscriber. The visiting network will also advise the home network of the temporarily assigned IP address. The home network stores the temporary IP address in an IP address translation database. The subscriber will then be able to communicate with his home network from the remote network and receive all of the network services available to him from his home network. The subscriber utilizes a roaming terminal having a permanent IP address to connect to the visiting network.

Smart routers-simple optics a network architecture for IP over WDM

Abstract: A simple, general IP/WDM node architecture is prototyped, concentrating intelligence for optical and electronic resource management in IP, and exposing to IP a simple interface to WDM's capabilities for configurable bandwidth.

Method and arrangement for handling information packets via user selectable relay nodes

Abstract: The invention is related to a method in a communication network for handling traffic, such as data packets, from source nodes to destination nodes, via user selectable relay nodes. The relay nodes form an overlay network of nodes operated and managed by an overlay network operator. Communication between relay nodes relies on using packet forwarding services of intermediate networks being operated and managed independently by other operators. For any source/destination pair the overlay network operator may select an appropriate sequence of relay nodes to be passed depending on the required quality of service and the performance of different intermediate networks. The invention enables the control of the spreading of traffic between any two end-points over several alternative relay routes.

Implementing integrated and differentiated services for the Internet with ATM networks: a practical approach

Abstract: This article reports on design, implementation, and preliminary experimentation of a network architecture that supports quality of service for Internet applications. It gives an overview of the various approaches toward communication networks that support application-specific degrees of QoS. Special emphasis is put on the integrated and differentiated services approaches and on combinations of them. A new architecture is described which aims to bring these concepts closer to practical realization in wide-area networks. The new architecture supports the integrated as well as differentiated services approaches in a smoothly integrated way, and uses the capabilities of an underlying ATM network to realize QoS. The enhancements to the existing network infrastructure are deliberately limited to the integration of a single new type of network element called an edge device. The potential benefits of such an architecture for various stakeholders are explained, and how the new architecture could be introduced smoothly in existing networks by small migration steps, also covering networks based on technologies other than ATM. It is shown that the approach can be scaled up to a very large QoS-aware overlay network for the Internet.

Capacity management and routing policies for voice over IP traffic

Abstract: This article addresses the problem of designing capacity management and routing mechanisms to support telephony over an IP network. For this service, we propose two distinct architectural models. The first relies on enhancements to the basic IP infrastructure to support integrated service transport and QoS routing. The second assumes that the IP network can support an overlay virtual private network with dedicated capacity for the VoIP service, thereby allowing standard capacity management and routing mechanisms from circuit-switched networks to be reused. We evaluate the performance of these two architectural models and their-associated policies via simulations using configuration and usage data derived from operational networks.

On the cost of virtual private networks

Abstract: A virtual private network (VPN) is a private data network that uses a nonprivate data network to carry traffic between remote sites. An "Intranet VPN" establishes network layer connectivity between remote Intranet sites by creating an IP overlay network over the nonprivate network, using various tunneling mechanisms. There are two approaches for establishing such tunnels: a "CPE-based approach" and a "network-based approach." In the first approach, tunnels are established only between the CPE devices, whereas in the second approach tunnels are also established between the routers of the core nonprivate network. In this paper we address the problem of determining a CPE-based and a network-based layout of VPN tunnels while taking into account two factors: the cost of the links over which the VPN tunnels are established and the cost of the core routers that serve as end points for the VPN. We define related graph algorithm problems, analyze their complexity, and present heuristics for solving these problems efficiently.

Ip telephony system and method of operation thereof using ss7 network

Abstract: The invention is a communication system (100) and a method of communication. A communication system in accordance with the invention includes a first network (102) containing a plurality of first network entities (12) which originate and receive first network communications and to which the first network communications are addressed by a first address type associated therewith; and a second network (104), coupled to the first network, containing a plurality of second network entities (18) which originate and receive second network communications and to which the second network communications are addressed by a second address type associated therewith and which, in response to the second type of address, transmits second network communications associated with the second address type to at least one second network entity. The second network also receives first network communications from the first network entities and delivers the first network communications to at least one second network entity. A managing network (557), associated with the first network, manages operation of the first network including first network communication setup and routing and control thereof and provides address mapping between an address of the first type of the at least one second network entity to which the first network communications are addressed from the first network entities and an assigned address of the second type of the at least one second network entity which receives the first network communications and provides the assigned address to the second network in association with the second network communications. The second network delivers the first network communications to the at least one second network entity addressed with the assigned address of the second type associated with the second network communications.

The role of Internet technology in future mobile data systems

Abstract: Mobile telephony and the Internet are the fastest growing businesses in the telecommunications market. This is why most operators and service providers are looking after the development of new services in both sectors, and newcomers are expected to enter the arena. The mobile operators foresee an increasing share of their revenues coming from new data services, while Internet service providers are attracted to wireless technology and mobility services both to reduce costs within the last-mile segment and to enrich their market share, providing ubiquitous access to the Internet and corporate intranets. In this scenario several wireless overlay networks will coexist, and their interworking will be a challenging objective. The employment of Internet technology, with its novel mobility and security extensions, seems to be the most attractive option for achieving that goal. In addition, the migration to a full IP network architecture, even within each specific wireless domain, will be another promising opportunity, already under consideration within several technical and standardization bodies. The envisioned role of Internet technology makes it worthwhile to undertake significant research efforts on the development of innovative IP-based mobile data systems, and opens promising opportunities for both telcos and Internet service providers.

The next-generation Internet: unsafe at any speed?

Abstract: Speed alone will not make future Internet applications secure. I propose a new networking isolation capability, termed a virtual overlay network (VON). Such software-based virtual networks, layered on top of physical networks, may provide the isolation that critical applications need. Although a VON offers a response to the reliability and security needs of critical applications, it would be prohibitively costly to implement using contemporary technologies. Extending an existing router feature and coupling it with well-understood group communication techniques, however, could support VONs at low cost, with good scalability.

Method and system for dual-network address utilization by virtual tunneling

Abstract: A method and system for dual network address utilization. The methods and system described herein may help the transition from Internet Protocol version-4 ('IPv4') networks to Internet Protocol version-6 ('IPv6') networks. Dual address allocation on IPv4 (50) and/or IPv6 (88) network addresses is provided via a dual protocol stack. Network devices may communicate with legacy IPv4 networks while using IPv6 network addresses on an IPv6 network for local communications. IPv6 (122) over IPv4 (120) remote virtual tunnels are used to allow network devices using IPv6 network addresses on a local IPv6 network to communicate with remote IPv6 networks over IPv4 public networks (e.g., the Internet). IPv4 (130) over IPv6 (128) local virtual tunnels may be used to allow network devices to using IPv4 network addresses on a local IPv6 network to communicate with remote IPv4 public networks. The IPv4 addresses allocated include IPv4 addresses that may be allocated and used for Distributed Network Address Translation ('DNAT') and/or the Realm Specific Internet Protocol ('RSIP'). The method and system can be used with virtually any set of networks that requires transitions between X-bit and Y-bit network addresses and dual network address utilization.

Gateway system having controller and signal processor for interconnecting IP network and telephone network and method for controlling alternative routing at the time of fault of gateway system

Abstract: To detect network faults or congestion of traffic at an interface of a gateway system for connecting an IP network and a telephone network on the side of the IP network and to allow the IP network to control alternative routing at the telephone network, network faults and congestion of traffic on the side of the IP network are monitored by the gateway system having an interface function between the telephone network and the IP network. When a network fault or congestion of traffic is detected, the gateway system notifies the telephone network upstream thereof of the disabled line and instructs the same to perform alternative routing, which makes it possible to prevent the occurrence of a situation in which the quality of communication at the interface between the telephone network and IP network can not be maintained.

Method and system for evaluating network security

Abstract: A method for automatically identifying from an ordinary station connected to a TCP/IP network, the network components managed by a network management station for which it is possible to read or write over the confidential network data they store. Starting from the list of the default passwords protecting the network data and the IP addresses of the network components communicating with the ordinary station, the method allows by repeating the IP address discovery process, to discover step by step the passwords used in all the network components managed by the network management station and try to use them in reading or writing network information. The method allows detecting the lack of protection by password which usually occurs in campus networks and thus auditing such networks against intrusion from one of the stations of the network.

Exposing the network: support for topology-sensitive applications

Abstract: One of the traditional goals of networking has been to hide details of network topology from end users. As networks become larger and more heterogeneous, however, situations arise in which the ability to identify particular topological properties enables capabilities and performance that are difficult to achieve with a purely "black box" interface to network topology. Examples of such situations include deployment of active networking functionality to strategic points (e.g., upstream from a lossy link) or the construction of a secure overlay topology on a network with selective support for IP security. On the other hand, an approach that "opens up" the network without constraints seems neither necessary nor practical. We therefore propose a method to query and synthesize network information that allows constrained programmability. We demonstrate the method on a set of examples, and we discuss our implementation within an active networking environment.

Application, design, and evolution of WDM in GTS's pan-European transport network

Abstract: A pan-European transport network must cope with enormous traffic inflation by introducing appropriate network solutions. WDM technology is the solution adopted by GTS, driven by capacity requirements, infrastructure availability, flexibility, and cost. The deployment of this new technology presents specific technical issues, but more important, it lays the foundation of future optical networking. We describe the motives underlying the deployment of WDM technology in the long-haul and short-haul areas of GTS's operational transport network. Next, after presenting the use of WDM as the multiservice platform for SDH and IP overlay networks as well as native WDM services, we focus on the design of SDH-over-WDM and IP-over-WDM networks. Finally, we discuss future WDM networking and management requirements to better serve the needs of a pan-European carrier such as GTS.

Optical layer signaling: how much is really needed?

Abstract: This article challenges the emerging industry trend of adapting Internet-style distributed network-control with its full complexity for the optical transport network. Instead, we argue that an extensive telecom-style network management interface augmented with a minimal control plane and a service layer interface between management systems is more appropriate for the real needs of the optical layer. This approach will allow more flexibility in extending the interoperability between vendors and carriers as our understanding of these networks grows, increase the reliability of the network, and be a better fit for the telecom service provider. On the other hand, the simplicity of use and automation the Internet control plane promises can just as easily be achieved with our proposal.