SIGNET
Mitarbeiter: Xiaoming Fu ,
Dieter Hogrefe ,
Ingo Juchem ,
Niklas Steinleitner ,
Constantin Werner
Projektpartner: Columbia University, Siemens, German Telecom, Nokia, University of Cambridge, Technical University Braunschweig, University of Helsinki, Ericsson
This project develops communication protocols that can be used to provide various signaling services, such as Quality of Service resource reservation setup or firewall configuration in network nodes along the data path of end-to-end communications in IP-based networks.
Referenzen Documents Publikationen of this project:
2008
Overhead and Performance Study of the General Internet Signaling Transport (GIST) Protocol ,
Xiaoming Fu , Dieter Hogrefe , Henning Schulzrinne, Hannes Tschofenig, and Christian Dickmann, IEEE INFOCOM 2006, Bacelona, Spain,
IEEE, 2008.
Zusammenfassung lesen
The General Internet Signaling Transport (GIST) protocol is currently being developed as the base protocol component in the IETF Next Steps In Signaling (NSIS) protocol stack to support a variety of signaling applications. In this paper we present our study on the protocol overhead and performance aspects of GIST. We quantify network-layer protocol overhead and observe the effects of enhanced modularity and security in GIST. We developed a first open source GIST implementation at the University of Göttingen, and study its performance in a Linux testbed. A GIST node serving 45,000 signaling sessions is found to consume small amounts of CPU and memory (on average 1.1ms for processing a signaling message and 2.4KB memory for a session). Individual routines in the GIST code are instrumented to obtain a detailed profile of their contributions to the overall system processing. Important factors in determining performance, such as the number of sessions, state management, refresh frequency, timer management and signaling message size are further discussed. We investigate several mechanisms to improve GIST performance so as to be comparable with an RSVP implementation.
PDF [181.9 kB]
2007
General Internet Signaling Transport (GIST) over SCTP ,
Xiaoming Fu , Christian Dickmann, and Jon Crowcroft, Internet Engineering Task Force, Next Steps in Signaling (NSIS) Working Group,
March 2007.
Zusammenfassung lesen
The General Internet Signaling Transport (GIST) protocol currently uses TCP or TLS over TCP for connection mode operation. This document describes the usage of GIST over the Stream Control Transmission Protocol (SCTP). The use of SCTP can take the advantage of features provided by SCTP, namely streaming-based transport, support of multiple streams to avoid head of line blocking, and the support of multi-homing to provide network level fault tolerance. Additionally, the support for the Partial Reliability Extension of SCTP is discussed.
PDF [19.9 kB]
2006
Beyond QoS Signaling: a Generic IP Signaling Framework ,
Xiaoming Fu , Dieter Hogrefe , and Hannes Tschofenig, Computer Networks, Volume 50, Issue 17, pages 3416-3433,
Elsevier, December 2006.
Zusammenfassung lesen
This paper describes the design principles and an introduction of a framework and protocols for generic IP signaling, namely the Cross-Application Signaling Protocol (CASP) and its signaling applications. While reusing certain features of the existing RSVP protocol, CASP overcomes its shortcomings and may be deployed as a replacement technology to provide simpler, mobility-supported, more extensible and more secure signaling services in IP based networks. This paper discusses challenges of today?s IP signaling protocols and addresses fundamentals and key aspects of CASP and its current signaling applications. In addition, a comparison with previous signaling protocol proposals and an outlook of future work in this area are also given.
PDF [272.8 kB]
Securing the Next Steps in Signalling (NSIS) Protocol Suite ,
Xiaoming Fu , and Hannes Tschofenig, International Journal of Internet Protocol Technology, Volume 1, No. 4, pages 271-282,
InderScience Publishers, ISSN 1743-8209, August 2006.
Zusammenfassung lesen
The Next Steps In Signalling (NSIS) protocol suite represents an extensible framework for enabling various signalling applications over IP-based networks. The framework consists of two layers that need different types of security protection; the lower layer mainly deals with the discovery of adjacent peers and establishment of channel security to protect the delivery of signalling messages between two peers, while the upper layer provides the signalling application specific functionalities. Different security properties are required at the two layers with stronger authorisation functionality at the signalling application layer. In this paper we examine how various security vulnerabilities can be utilised by an adversary, including eavesdropping, Man-In-The-Middle (MITM) attacks, fraud and Denial of Service (DoS) attacks. Moreover, we describe how to protect against a number of selected security threats and highlight some security challenges that require further research.
PDF [431.5 kB]
Implementation and Performance Study of a New NAT/Firewall Signaling Protocol ,
Xiaoming Fu , Niklas Steinleitner , Henning Peters, and Hannes Tschofenig, in Proceedings of the 26th International Conference on Distributed Computing Systems-Workshops (ICDCSW 2006), the 5th International Workshop on Assurance in Distributed Systems and Networks (ADSN2006), Lisboa, Portugal,
IEEE Computer Society, ISBN 0-7695-2541-5, July 2006.
Zusammenfassung lesen
The NAT/Firewall NSIS Signaling Layer Protocol (NAT/FW NSLP) is a path-coupled signaling protocol for explicit Network Address Translator and firewall configuration within an extensible IP signaling framework currently being developed by the IETF Next Steps in Signaling (NSIS) working group. This new protocol allows end hosts to signal along a path to configure NATs and firewalls according to the data flow needs. In this paper we present a first open source implementation and performance evaluation of the NAT/FW NSLP protocol. The implementation utilizes a generic state machine template and can automatically generate source code for message handling classes. The performance study shows that our implementation scales well and is able to support firewall signaling for up to tens of thousands of flows in parallel even in a low-end PC testbed environment. The overall performance bottleneck is found to lie in the utilized firewall implementation, not depending on the NAT/FW NSLP implementation.
PDF [394.6 kB]
Modelling Soft-State Protocols with SDL ,
Xiaoming Fu , Dieter Hogrefe , IEE Proceedings Communications,
ISSN 1350-2425, Volume 153, Issue 3, pages 365-375, June 2006.
Principles and Experiments of Explicit Delay Control ,
Xiaoming Fu , Xiaoyuan Gu, Dirk Markwardt, and Lars Wolf, Proceedings of IEEE Consumer Communications and Networking Conference (CCNC'06), Las Vegas, USA,
IEEE, January 2006.
Zusammenfassung lesen
Real-time interactive multimedia applications are highly delay-sensitive, and packets that are out of delay boundaries are usually obsolete. However the current Internet Protocol lacks a way to control the lifetime of the packets explicitly. We propose a packet lifetime control mechanism called Explicit Delay Control (EDC) that embeds a Maximum Tolerable Delay (MTD) field in an IPv4 option. At each network node, the MTD is deducted by the singlehop delay. Packets that expire their lifetime are discarded and non-congestion related delay losses are signaled to the sender to reduce inaccuracy in delay estimations and to adapt to path changes. We implemented EDC in the Linux kernel. Our evaluation has shown that EDC is an effective scheme to ensure the ?legality? of the packets, reduce the waste of bandwidth and processing time in the networks, and alleviate congestions.
PDF [207.6 kB]
2005
A Quality-of-Service Resource Allocation Client for CASP ,
Xiaoming Fu , Henning Schulzrinne, Hannes Tschofenig, and Jochen Eisl, Technical Report No. TB-IFI-2005-07, Institute for Informatics, University of Goettingen, Germany,
ISSN 1611-1044, November 2005.
Zusammenfassung lesen
Signaling resource reservations is one of the possible applications of the Cross-Application Signaling Protocol (CASP). This document describes a client protocol that supports per-flow resource reservationin both sender- and receiver-directed modes operation.
PDF [99.8 kB]
Security Implications of the Session Identifier ,
Xiaoming Fu , Hannes Tschofenig, Henning Schulzrinne, Robert Hancock, and Andrew McDonald, Technical Report No. TB-IFI-2005-08, Institute for Informatics, University of Goettingen, Germany,
ISSN 1611-1044, November 2005.
Zusammenfassung lesen
As one result of the analysis activities in the NSIS group it was realized that mobility and the ability to change the flow identifier causes problems with existing QoS reservations. To be able to associate a signaling message with existing state an identifier other than the flow identifier had to be used. Such an abstraction is achieved with the session identifier which allows identification of established state independently of the flow characteristics.
Although the introduction of a session identifier sounds simple and beneficial, it introduces a problem which is subsequently referred to as the session ownership problem.
This document describes the session ownership problem, the implications for an NSIS protocol and summarizes already discussed solutions.
PDF [79.7 kB]
NSIS: A New Extensible IP Signaling Protocol Suite ,
Xiaoming Fu , Dieter Hogrefe , Henning Schulzrinne, Attila Bader, Cornelia Kappler, Georgios Karagiannis, Hannes Tschofenig, and Sven Van den Bosch, IEEE Communications Magazine, Internet Technology Series, pages 133-141,
IEEE, October 2005.
Zusammenfassung lesen
In the last few years, a number of applications have emerged that can benefit from network-layer signaling, i.e., the installation, maintenance and removal of control state in network elements. These applications include path-coupled and path-decoupled quality of service (QoS) management and resource allocation, as well as network debugging, NAT and firewall control. These applications call for an extensible and securable signaling protocol. This paper discusses some of the recent standardization efforts in the IETF for a new extensible IP signaling protocol suite (NSIS). We describe the design of the NSIS protocol suite, and compare them with RSVP, the current Internet QoS signaling protocol.
PDF [159.9 kB]
Fast Seamless Handover Scheme and Cost Performance Optimization for Ping-Pong Type of Movement ,
Xiaoming Fu , Zongkai Yang, Yuming Wang, Dasheng Zhao, and Jianhua He, Proceedings of the 16th Annual IEEE International Symposium on Personal Indoor and Mobile Radio Communications (PIMRC 2005), Berlin, Germany,
IEEE, September 2005.
Zusammenfassung lesen
The ping-pong type of movement is a typical motion manner in mobile IPv6 networks, which will bring frequent handovers and thus increase signaling burden. On the other hand, reducing handover delay in this case seems to be more significant. In this paper we propose a fast seamless handover scheme for the ping-pong type of movement as an extension to the hierarchical mobile IPv6. Based on the simulation results, it can be observed that, by setting the reservation active flag (RAF) and the offline count down timer (CDT), the scheme significantly reduces QoS signaling cost and handover delay. Furthermore, the simulations work out an optimized CDT for acquiring better cost performance of resource reservation.
PDF [286.8 kB]
Advanced Authentication and Authorization for Quality of Service Signaling ,
Xiaoming Fu , Tseno Tsenov, Hannes Tschofenig, and Eckhart Koerner, 1st IEEE/CreatNet Workshop on Security and QoS in Communication Networks (SecQoS 2005), Athens, Greece (in conjunction with the first IEEE International Conference on Security and Privacy for Emerging Areas in Communication and Networks - SECURECOM 2005),
IEEE Computer Society Press, September 2005.
Zusammenfassung lesen
One of the key requirements of today?s and future network infrastructures is to provide Quality of Service (QoS) support for end-to-end applications, by distinguishing the application flows and properly handling them in network nodes. As an important component to achieve Internet QoS, explicit signaling schemes for resource reservation have been proposed, which deal with admission, installation and refreshment of QoS reservation state information. To be useful, any QoS signaling protocol should provide a capability for authentication and authorization of the QoS requests, especially in environments where the end points are not trusted by the network nodes. However, existing protocols for QoS signaling encounter a number of authentication and authorization issues, which limit their application scenarios. The advent of NSIS QoS Signaling Layer Protocol (QoS-NSLP) offers the prospect to overcome some of these issues. After describing the overall design of QoSNSLP, we present an approach to support advanced authentication and authorization capabilities by using the Extensible Authentication Protocol (EAP). In comparison with existing approaches, this approach, combined with the support for effective interaction with the Authentication, Authorization and Accounting (AAA) infrastructure, provides flexible and extensible authentication and authorization methods for the QoS signaling.
PDF [959.2 kB]
RSVP Standards Today and the Path Towards a Generic Messenger ,
Xiaoming Fu , Jukka Manner, In: H. de Meer and N. Bhatti (eds.), Proceedings of the 13th International Workshop on Quality of Service (IWQoS 2005), Passau, Germany, Lecture Notes in Computer Science, Volume 3552,
Springer Verlag, ISBN 3-540-26294-6, June 2005.
Zusammenfassung lesen
RSVP is a very well-known protocol to support resource reservations in IP-based networks. This paper provides a preliminary inventory of RSVP standards and discusses the path towards a generic messenger for Internet signaling.
PDF [62.4 kB]
Modeling Route Change in Soft State Signaling Protocols Using SDL: a Case of RSVP ,
Xiaoming Fu , Dieter Hogrefe , Constantin Werner , in A. Prinz, R. Reed and J. Reed (eds.), Proceedings of the 12th SDL Forum (SDL 2005), Grimstad, Norway, Lecture Notes in Computer Science, Volume 3530, pages 174-186,
Springer Verlag, ISBN 3-540-26612-7, June 2005.
Zusammenfassung lesen
Soft state signaling protocols install and maintain states in network nodes, expiring without receiving refreshes. These states require proper reparation when the flow path changes, especially in case of link or node failures. As the specifications usually do not describe in detail how to handle these failures, we present insights by developing SDL models for RSVP on this issue.
PDF [269.3 kB]
Modeling Soft State Protocols with SDL ,
Xiaoming Fu , Dieter Hogrefe , In: R. Boutaba et al. (Eds.), Proceedings of the 4th IFIP International Conference on Networking (Networking 2005), Waterloo, Canada, Lecture Notes in Computer Science, Volume 3462, pp. 289-302,
Springer Verlag, ISBN 3-540-25809-4, May 2005.
Zusammenfassung lesen
Soft state provides new services to packet-switching networks by introducing a type of state in the network nodes which is refreshed by periodical messages and otherwise expires. The operations of soft state protocols, which are being designed with ever greater complexity, need to be error-free and deadlock-free to avoid misusing network resources. Thus, verification, formal analysis and validation of these protocols become a vital task. In this paper we utilize formal techniques, specifically Specification and Description Language (SDL) and Message Sequence Charts (MSCs), for modeling, analysis and validation of various soft state protocols. We propose a general architecture for state management systems and find employing these techniques can help identify and correct possible design errors, which may be caused by informal specifications.
PDF [162.9 kB]
Analysis of Existing Quality-of-Service Signaling Protocols ,
Xiaoming Fu , and Jukka Manner, Request for Comment (RFC) 4094,
Internet Engineering Task Force, May 2005.
Zusammenfassung lesen
This document reviews some of the existing Quality of Service (QoS) signaling protocols for an IP network. The goal here is to learn from them and to avoid common misconceptions. Further, we need to avoid mistakes during the design and implementation of any new protocol in this area.
PDF [68.0 kB]
2004
Implementation and Evaluation of the Cross-Application Signaling Protocol (CASP) ,
Xiaoming Fu , Dieter Hogrefe , and Sebastian Willert, Proceedings of the 12th IEEE International Conference on Network Protocols (ICNP 2004), Berlin, Germany, pp. 61-71,
IEEE Computer Society Press, ISBN 0-7695-2161-4, October 2004.
Zusammenfassung lesen
In this paper, we describe implementation aspects and performance results of a novel general signaling protocol for the Internet, the Cross-Application Signaling Protocol (CASP). There has been much debate on the applicability of RSVP as a general signaling protocol for the Internet, particularly with respect to its modularity, complexity, security and mobility support. Based on a layered architecture, the CASP design intends to address these challenges, which, unlike RSVP, provides a simpler mechanism for reliability and security by re-using existing protocols for transporting signaling messages. In addition, it supports a wide range of signaling applications. While this concept is considered to be advantageous over RSVP signaling, the actual mechanisms and behaviors of the CASP implementation have not yet been explored. Our study attempts to shed light on this issue by presenting a first public CASP implementation and preliminary examination of its properties. Performance results show and analyze the round trip times and their variances of signaling messages upon different number of signaling requests and different congestion situations in the experimental setup. The memory required for a large number of signaling sessions and the CPU consumption for each routine from profiling the implementation are low. Although further work is necessary, critical design choices in CASP have been proven useful and practically feasible.
PDF [111.3 kB]
Modeling Soft State Protocols with SDL ,
Xiaoming Fu , Dieter Hogrefe , Technical Report No. IFI-TB-2004-02, Institute for Informatics, University of Göttingen, Germany,
ISSN 1611-1044, August 2004.
Zusammenfassung lesen
Soft state enables new services to packet-switching networks by introducing a type of state in the network nodes which is refreshed by periodical messages otherwise expire. System designers build protocols that implement soft state concepts based on intuition or on high-level explanations believe that the design is "better" than hard state and soft state implementations should be robust, reliable and interoperable. As states in the network nodes are critical for both applications the and network infrastructure, the operations of soft state protocols, which tend to be designed more and more complex, need to be error-free and deadlock-free. Thus, verification, formal analysis and validation of these protocols become a vital task. In this paper we utilize formal techniques, specifically, Specification and Description Language (SDL) and Message Sequence Chart (MSC), for modeling, analysis and validation of general soft state protocols. We propose a general architecture of state management systems and find several points through the SDL/MSC modeling which may enrich the design, modeling and evaluation of real soft state protocols: 1) modeling these protocols using these techniques is feasible, 2) it can be possible to use these techniques to identify possible design errors and deadlocks/livelocks, which may be caused by imprecise informal specifications of these protocols.
PDF [112.1 kB]
Implementation and Evaluation of the Cross-Application Signaling Protocol (CASP) ,
Xiaoming Fu , Dieter Hogrefe , and Sebastian Willert, Technical Report No. IFI-TB-2004-001, Institute for Informatics, University of Göttingen, Germany,
ISSN 1611-1044, April 2004.
Zusammenfassung lesen
In this report, we describe implementation aspects and performance results of a novel general signaling protocol for the Internet, the Cross-Application Signaling Protocol CASP). Much debate exists about the applicability of RSVP as a general signaling protocol in the Internet, particularly for its modularity, complexity, security and mobility support. Based on a layered architecture, the CASP design intends to address these challenges and unlike RSVP, it provides a simpler mechanism for reliability and security by re-using existing protocols for transporting signaling messages, and supports a wide range of signaling applications. While this concept is considered to be advantageous over RSVP signaling, the actual mechanisms and behaviors of the CASP implementation have not yet been explored. With our work, despite being still far from a final judgment, we try to shed light on this issue by presenting a first public CASP implementation and a preliminary study about its properties. Performance results show that even under heavy signaling loads, the round trip time of signaling messages is acceptable (appr. 5ms in serving more than 1000 simultaneous signaling client applications in the initiator each at a random refresh interval between 3s and 15s in our experiments), and the memory and CPU consumption of the implementation are low. Although further work will be necessary, critical design choices in CASP have been proved to be feasible.
PDF [416.3 kB]
2003
Development of QoS Signaling Protocols in the Internet ,
Xiaoming Fu , Proceedings of the 28th Annual IEEE Conferfence on Local Computer Networks (LCN 2003), Bonn/Königswinter, Germany, pp. 636-637, Workshop on High-Speed Local Networks,
IEEE Computer Society Press, ISBN 0-7695-2037-5, October 2003.
Zusammenfassung lesen
QoS signaling protocol is one of the key components in Internet QoS architectures to establish, maintain, and remove reservation states in network nodes. This paper gives an overview of the recent efforts underway on next steps in QoS signaling protocols, namely RSVP extensions with mobility support, QoS-conditionalized handoff protocol, the layered architecture RSVP Lite and the Cross-Application Signaling Protocol (CASP). These efforts address main issues with existing approaches differently : modularity, complexity and mobility support, with a focus on protocol behaviors based on different design principles. The paper also provides pointers to standards effort towards general Internet signaling and other service-specific signaling protocols.
PDF [39.6 kB]
Mobility Support for Next-Generation Internet Signaling Protocols ,
Xiaoming Fu , Henning Schulzrinne, and Hannes Tschofenig, Proceedings of the IEEE 58th Vehicular Technology Conference (VTC 2003-Fall), Orlando, Florida, USA, pp. 1979-1983, Symposium on IP Mobility,
IEEE, ISBN 0-7803-7954-3, October 2003.
Zusammenfassung lesen
Internet signaling protocols establish, maintain and remove state along the data path. Next-generation signaling protocols design must meet the scaling requirements imposed by the various tasks of the Internet signaling applications, such as resource reservation and middlebox configuration, and to meet the demand for general functionality in signaling protocols, including strong security, reliability, congestion control, support for various signaling purposes and message sizes, and efficient support for mobility. This paper presents a generic signaling architecture, the Cross-Application Signaling Protocol (CASP) and describes how it supports efficient and secure signaling in IP mobility scenarios. In this approach, the signaling functionality is splitted into two layers: a generic messaging layer which provides the generic functionality for message delivery, and a client layer consisting of a next-hop discovery client and any number of client protocols which perform the actual signaling tasks. The essential mechanisms required to support mobility are: (1) a session identifier uniquely selected by the initiator and effective discovery of the cross-over node; (2) a branch identifier incrementally assigned for the new branch and efficient release of state in the abandoned branch; (3) ensuring discovery messages are delivered exactly following the path that mobile IP packets are encapsulated; (4) effective hop-by-hop authentication and reauthorization provided by the messaging layer, non hop-by-hop security for signaling clients and denial-of-service protection in the discovery client.
PDF [75.9 kB]
CASP ? Cross-Application Signaling Protocol ,
Xiaoming Fu , Henning Schulzrinne, Hannes Tschonfenig, and Andrew McDonald, Technische Berichte des Instituts für Informatik an der Georg-August-Universität Göttingen,
Institut für Informatik, Georg-August-Universität Göttingen, Germany, ISSN 1611-1044, IFI-TB-2003-01, (equivalent to the Internet draft ?CASP ? Cross-Application Signaling Protocol?, draft-schulzrinne-nsis-casp-01), March 2003.
Zusammenfassung lesen
CASP is a modular potocol for establishing network control state along a data path between two nodes communicating on the Internet.
The signalling problem addressed by CASP is the same as the overall problem being addressed by the NSIS activities.
The CASP framework is defined as a modular protocol, which includes a general purpose messaging layer (M-layer), which supports a number of client layers for particular ignalling applications (e.g. QoS, MIDCOM). In addition there is distinct, special purpose client component for next-peer discovery.
PDF [103.1 kB]
Towards RSVP Lite: Light-weight RSVP for Generic Signaling ,
Xiaoming Fu , Cornelia Kappler, Proceedings of the 17th International Conferfence on Advanced Information Networking and Applications, Xi'an, China, pp. 619-622,
IEEE Computer Society Press, ISBN 0-7695-1906-7, March 2003.
Zusammenfassung lesen
RSVP is a reservation setup protocol designed specifically to support QoS signaling in the Internet. However, RSVP end-to-end signaled QoS for the Internet has not become a reality. Moreover, there are many other applications demanding different signaling services. This paper analyses the features of RSVP version 1 we believe to be essential, and its complexity due to QoS-oriented design and multicast support as an indispensable component in a signaling protocol, deriving the design principles to be covered in a more generic signaling protocol. Based on this analysis, we present a light-weight version of RSVP, RSVP Lite, which clearly separates the signaled data from signaling messages and removes the multicast capability from the mandatory components of RSVP. RSVP Lite is intended to be applicable to a wide range of networking environments, while providing the flexibility to serve for generic signaling purposes and incremental deployment in the Internet.
PDF [42.9 kB]
Design of CASP ? a Technology Independent Lightweight Signaling Protocol ,
Xiaoming Fu , Henning Schulzrinne, Cornel Pampu, and Cornelia Kappler, Proceedings of the 1st International Workshop on Inter-domain Performance and Simulation (IPS 2003), Salzburg, Austria,
February 2003.
Zusammenfassung lesen
Existing signaling solutions are insufficient in terms of inter-domain and out-of-path signaling, mobility support and inter-working with policy and security mechanisms. The paper presents the Cross-Application Signaling Protocol (CASP) which is a general-purpose protocol for managing state information in network devices. This technology independent signaling protocol can be used for inter- and intra-domain QoS signaling, the configuration of middleboxes, for collecting measurement data and any other application where state management is required. It relies on existing transport protocols and consists of a messaging layer and a client layer. The messaging layer is application independent and is responsible for routing, session establishment and feature negotiation. In contrast to this application independent component of CASP, the client layer is the application-dependent part. As an example for a client the paper describes the QoS Resource Allocation Client for CASP and discusses requirements for extending CASP to include interdomain signaling. The discovery of next peers along the data path is handled by the Scout protocol, which is a specialized client protocol. Some of the basic mechanisms are derived from existing protocols. This way the design of this protocol relies on the experiences made in this area and is therefore one of the promising protocol candidates for the IETF NSIS WG.
PDF [48.2 kB]
2002
Analysis on RSVP Regarding Multicast ,
Xiaoming Fu , Cornelia Kappler, and Hannes Tschofenig, Technische Berichte des Instituts für Informatik an der Georg-August-Universität Göttingen,
Institut für Informatik, Georg-August-Universität Göttingen, Germany, ISSN 1611-1044, IFI-TB-2002-001, October 2002.
Zusammenfassung lesen
RSVP version 1 has been designed for optimum support multicast. However, in reality multicast is being used much less frequently than anticipated. Still, even for unicast (one sender, one receiver) full-fledged multicast-enabled RSVP signaling must be used. As pointed out in the NSIS requirement draft, multicast would not be necessarily required for an NSIS signaling protocol. This draft analyses ingredients of RSVP Version 1 which are affected by multicast, and derives how these ingredients may look like if multicast is not supported in the generic RSVP signaling protocol and adapt related functionalities accordingly - we call the resulting feature set "RSVP Lite", a potentially more light-weight version of RSVP.
PDF [335.7 kB]
