Providing and verifying advanced IP services in hierarchical DiffServ networks‐the case of GEANT

The differentiated services (DiffServ) framework is widely proposed as an efficient method for providing advanced IP services to large‐scale networks, with QoS requirements. However, the provisioning of such services in production networks has proved to be more difficult than initially expected, in defining, setting and verifying appropriate Service Level Agreements (SLAs). GEANT, the Gigabit core pan‐European research network, on a pilot basis introduced ‘Premium IP’ service, offering bounded delay and negligible packet loss to the European National Research & Education Networks (NRENs) that it interconnects. However, large scale provisioning of this new service requires the definition of efficient interaction procedures between administrative domains involved and methods for SLA monitoring. This paper focuses on these issues and presents the experience acquired from the early experiments in GEANT, as an example of hierarchical Gigabit multi‐domain environment, enabled with QoS provisioning to its constituent NRENs. This model scales more efficiently than the common peering Internet Service provider (ISP) commercial paradigm. Finally, we outline other options that promise QoS, such as Layer 2 VPNs in MPLS backbones, with non‐standard (yet) mechanisms. Copyright © 2004 John Wiley & Sons, Ltd.     

The interface between IP and WDM and its effect on the cost of survivability

A summary of research on survivable IP networks overlaid over WDM networks is presented. The WDM networks are part of optical transport service providers, who lease lightpath services to institutions with IP networks. The lightpath services realize IP links for IP networks, and they have different protection grades such as unprotected and protected. The research included considering new network survivability requirements and incorporating them into network design problems. The cost of survivable IP over WDM networks is compared over three scenarios. Each succeeding scenario has the WDM network provide more flexible services, and the IP and WDM networks become more integrated. We consider the problem of setting up lightpaths for an IP network so that the network will remain connected after a fiber link fault. Algorithms to find the lightpaths and minimize cost are given. The network costs under the three scenarios are compared by simulations.     

A Study of the Next Generation Intelligent Networks Interworking with IP Networks

A Study of the Next Generation Intelligent Networks Interworking with IP Networks     

On management of CATV full service networks: a European perspective

The CATV network operators hope to offer digital services and evolve their networks to full service networks. There are many hurdles for them at the moment in the transition to a digital network and digital service offering from the current analog-based technology. Key to the success of the transition will be a well-integrated and capable management system to allow CATV operators and service providers to control the network as well as the services they will offer. The CATV operators need to agree on a common data communication infrastructure and plan how their new digital services will be offered to subscribers without disrupting the current customer base of analog service users. The choice of network technology and data communication protocols will have a strong influence on the network management technology chosen. A vital element for the provision of a common open communication architecture as well as for the purposes of network management is that the IP is used. The adoption of existing standards is vital in order to establish a fast route to open network management for CATV networks. It is possible that CATV operators and service providers will have to integrate existing SNMP management systems and TMN/OSI management, with newer integrated service management systems based on TINA and implemented on a CORBA platform. There is a strong need to address security issues before any of these technologies can be deployed for service. There is currently investment (deployed systems and research) which uses each of the technologies mentioned, so these technologies will need to coexist. This article highlights the differences between the North American and European network architectures, and outlines the European network and network management scenario. This is based on the authors involvement in a Pan-European CATV project, Integrated Broadband Communication over Broadcast Networks-IBCoBN     

一种网络化的业务识别系统

下一代网络（NGN）是业务驱动网络,业务识别与控制对NGN的管理和安全具有重要意义。目前业务流识别技术的识别能力范围局限在单一设备上,容易导致识别不出或误识别业务流。未来的业务识别技术应该是基于网络形式的、动态的识别。在TCP/IP体系结构的基础上,通过对现有业务流识别技术的研究,设计出一种基于IP网络的网络化业务流识别系统模型。     

ATM in MPLS-based converged core data networks

Services supported by asynchronous transfer mode account for the majority of data and Internet service revenues generated by carrier networks today. This is based on ATM's ability to support high availability services with quality of service. However, the influences of the Internet and a highly dynamic telecommunications market have raised demands for increased flexibility while controlling costs. Therefore, future carrier networks are likely to continue to be based on established technologies, such as ATM, as well as IP. In many cases, this is achieved through maintaining separate ATM and IP core networks, with the IP network supporting Internet services, while the ATM network continues to support guaranteed services such as private lines, broadband access, and video. In some cases, however, it can be advantageous for a carrier to transport segments of their ATM network over their IP network core; for example, to transport ATM traffic currently carried on leased facilities onto an IP network where the service provider owns the facilities. Developments in IP and MPLS-based traffic engineering and QoS may increase the ability of IP-based networks to support ATM services using MPLS. This article provides an overview of approaches enabling a network based on MPLS that naturally supports IP services to also support ATM services. The drivers and requirements for convergence on an IP/MPLS core network are presented, followed by an overview of the different approaches and associated challenges currently being debated in the standards bodies.     

一种MPLS网络间的IP业务传送技术

当前跨多协议标记交换(MPLS)网络进行网间IP业务传送具有一定的局限性。详细描述了MPLS网络间辅以网关设备的IP业务传送技术,并提出接入网关和互连网关的设计方案,重点阐述了网关的模块组成和接口设计;结合在研的2种典型MPLS网络,利用AX4000测试仪对跨网的端到端IP业务传送性能进行分析,针对业务优先级和利用通道保护能力的IP业务传送指标进行测试,对测试数据和应用效果进行分析总结。     

Deterministic loss ratio quality of service guarantees for highspeed networks

Current research for the provision of deterministic quality of service guarantees in both IP networks and high speed networks involve only bounded delay guarantees, In this letter, loss ratio is considered. We propose constraints on the service function in order to provide not only deterministic bounded loss ratio under a given buffer capacity but also bounded delay. Network operation can be easily managed by existing service-function-based scheduling algorithms     

Toward IP virtual private network quality of service: a service provider perspective

To complement classical enterprise wide area network infrastructures, IP (based) virtual private networks have been gaining ground, with the capability of offering cost-effective, secure, and private-network-like services. In order to provision the equivalent quality of service of legacy connection-oriented layer 2 virtual private networks (VPNs), IP VPNs have to overcome the intrinsically best effort characteristics of the Internet in this multimedia era. This article discusses the IP VPN quality of service (QoS) issue from a service provider point of view, where QoS guarantees are carried out at the network level as well as at the node level. It presents the whole picture by highlighting and stitching together various QoS enabling technologies from previous research and engineering work.     

IP multimedia services: analysis of mobile IP and SIP interactions in 3G networks

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.     

VoIP mobility in IP/cellular network internetworking

This article explores VoIP mobility in the context of IP and cellular networks interworking. ITU-T Rec. H.323 gateways provide the interconnection between IP networks and switched circuit networks. They allow a call originating from an SCN phone to be transmitted over an IP network to an H.323 terminal, or bridged to another SCN phone. While H.323 provides interoperability with other SCN terminals, the major efforts have been focused on IP/wired SCN (PSTN, ISDN, etc.) interworking. In this article we discuss the challenges associated with the interworking between IP networks and cellular networks through H.323 gateways, and propose an innovative approach using the existing call transfer supplementary service to provide VoIP mobility in the H.323 IP telephony networks. The proposed approach uses existing components in the H.323 standard, thereby allowing VoIP mobility service in hybrid IP/cellular networks to be a value-added feature in the existing H.323-compliant Internet telephony systems     

Proportional differentiation: a scalable QoS approach

The proportional service model has gained attention as an effective solution for quantitative service differentiation in IP networks. In particular, this differentiation scheme is controllable, consistent, and scalable. Thus, it gives network operators convenient management of services and resources even in a large-scale network. We give an overview of research efforts on this QoS model. Details about implementation strategies for various QoS metrics are provided. We also discuss how to achieve absolute service bounds in this relative differentiation model with different approaches. Several problems such as feasibility in differentiation are mentioned as open research issues at the end.     

The IMS service platform: a solution for next-generation network operators to be more than bit pipes

As third-generation (mobile) networks (3G networks) become a commercial reality, strong movements are emerging in the direction of a common infrastructure based on the Internet protocol (IP). The users' mobile devices are like another IP host connected to the Internet. In such a scenario, the network operator infrastructure is degraded to bit pipes. To avoid this, the 3G partnership project (3GPP) and ETSI TISPAN have designed IP multimedia subsystem (IMS), a service platform that aims to place the network operator again in the central role of service provisioning. In this article we examine IMS from a mobile operator's perspective and analyse its possible adaptation to the next-generation networks.     

BRAIN—an architecture for a broadband radio access network of the next generation

The tremendous growth rates of the Internet as well as the area of mobile communications give rise to the chance that the mobile Internet is most promising by combining both the Internet and mobile communications. These prospects are the motivation for the European research project BRAIN (Broadband Radio Access for IP‐based Networks), which is developing an open architecture for a broadband wireless mobile access network offering an integrated communication platform across heterogeneous networks and, thus, goes beyond current third generation systems and towards the mobile Internet. The project covers three major technical areas: support of seamless service provision in a mobile environment; the design of an IP‐based access network that will support non‐cellular technologies such as wireless LANs; and requirements of a broadband air interface suitable for hot spots. BRAIN is going to integrate HIPERLAN/2 with UMTS by means of an IP access network. The work is guided by a user‐centric top‐down approach ensuring that user functionality is the key driver of the project. This article will focus on that part of the BRAIN work which specifies the main interfaces of the BRAIN architecture and deals with aspects related to the support of Quality of Service and mobility. Copyright © 2001 John Wiley & Sons, Ltd.     

从公路网的视角看IP QoS

本文从公路网的视角重新认识IP QoS问题,提出了互联网所需要和所能提供的是一种适合的、相对的、统计意义上的IP服务质量保证能力,并分析目前在网络实际应用中有助于改善IP QoS一些方法的成功之处,包括提高网络的硬件通行能力、提供差异化的服务质量保证、提高网络对流量的控制能力,最后讨论公路网对IP QoS下一步研究的一些启示.     

Service level agreements on IP networks

This paper provides an overview of service level agreements (SLAs) in IP networks. It looks at the typical components of an SLA and identifies three common approaches that are used to satisfy SLAs in IP networks. The implications of using the approaches in the context of a network service provider, a hosting service provider, and an enterprise are examined. While most providers currently offer a static insurance approach toward supporting SLAs, the schemes that can lead to more dynamic approaches are identified.     

可编程移动IP网络及其应用

将有市场需求的服务尽快地提供给用户是移动服务提供商竞争的焦点，但是目前的网络技术极大阻碍了新服务的市场化。针对这一情况，基于主动网络技术提出一种可编程移动IP网络，该网络体系结构可以快速创建和部署新的移动IP服务和协议，这样的网络结构大大加快了移动应用服务的市场化进程。基于可编程移动IP网络体系结构开发了一种主动式移动IP协议，证实了可编程移动IP网络在服务创建上的高效性。     

Design and Realization of a Novel Header Compression Scheme for Ad Hoc Networks

IP header compression schemes offer a valuable measure for bandwidth preservation. Such schemes have been practically implemented in infrastructure‐based IP networks for point‐to‐point links. However, minimal research and practical implementation efforts have been conducted in the direction of an IP header compression strategy that can meet the peculiar requirements of multi‐hop ad hoc wireless networks. In this paper, we present a practically implemented multi‐hop IP header compression scheme using the Robust Header Compression (ROHC) protocol suite. The scheme runs on a novel identifier (ID) based networking architecture, known as an ID‐based ad hoc network (IDHOCNET). IDHOCNET additionally solves a number of bottlenecks of pure IP‐based ad hoc networks that have emerged owing to IP address auto‐configuration service, distributed naming and name resolution, and the role of an IP address as an identifier at the application layer. The proposed scheme was tested on a multi‐hop test bed. The results show that the implemented scheme has better gain and requires only O (1) ROHC contexts.     

下一代网络通用移动性管理技术初探

针对下一代网络(NGN)的通用移动性要求,阐述了符合NGN全IP网络传送这一特点的两类移动性解决方案——基于网络层解决方案(移动IP)和基于应用层解决方案(移动SIP),比较了它们在支持终端移动性、个人移动性和业务移动性支持上的优缺点,进而分析两者结合方案,提出将网络层移动性管理进行联合优化设计,是研究NGN通用移动性管理技术的一种努力方向。     

利用上下文转移实现移动IPv6上的IMS无缝切换

Mobility support for the next generation IPv6 networks has been one of the recent research issues due to the growing demand for wireless services over internet. In the other hand, 3GPP has introduced IP Multimedia Subsystem as the next generation IP based infrastructure for wireless and wired multimedia services. In this paper we present two context transfer mechanisms based on predictive and reactive schemes, to support seamless handover in IMS over Mobile IPv6. Those schemes reduce handover latency by transferring appropriate session ＇information between the old and the new access networks. Moreover, we present two methods for QoS parameters negotiations to preserve service quality along the mobile user movement path. The performances of the proposed mechanisms are evaluated by simulations.