Multicast Papers Appeared in 1997

Scalable Delivery of Web Pages Using Cyclic Best-Effort (UDP) Multicast. Kevin C. Almeroth, Mostafa H. Ammar and Zongming Fei. (GIT-CC-97-20)

A Scalable and Robust Feedback Mechanism for Adaptive MultimediaMulticast Systems. A. Youssef, H. Abdel-Wahab and K. Maly. (TR_97_38)

Application-Layer Group Communication Server for Extending Reliable Multicast Protocols Services. Ehab Al-Shaer, Hussein Abdel-Wahab and Kurt Maly. (TR_97_32)

An Internet Collaborative Environment for Sharing Java Applications. H Abdel-Wahab, B Kvande, O. Kim and J. P. Favreau. (TR_97_20)

Distributed Management of Exclusive Resources In Collaborative Multimedia Systems. Hussein Abdel-Wahab, Alaa Youssef and Kurtwahab@cs. Maly. (TR_97_18)

Efficient Multicast Flow Control using Multiple Multicast Groups. S. Bhattacharyya. (UM-CS-1997-015)

Stateful Multicase Services for Supporting Collaborative Applications. Hyong Sop Shim, Robert W. Hall, Radu Litiu and Atul Prakash. (CSE-TR-351-97)

Netzwerk-Management und Hochgeschwindigkeits- Kommunikation. Teil XV. Seminar WS 1996/97.. Roland BLESS, [Hrsg.], Claudia SCHMIDT, Elmar DORNER, Jochen SEITZ and Markus HOFMANN. (iratr-1997-5)

Q. Sun and H. Langendoerfer, A Distributed Delay-Constrained Dynamic Multicast Routing Algorithm, in European Workshop on Interactive Distributed Multimedia Systems and Telecommunication Services (IDMS'97) , Lecture Notes in Computer Sciences, Vol. 1309, pp97-106, Springer-Verlag, 1997

Kevin C. Almeroth and Mostafa H. Ammar, "Multicast group behavior in the internet's multicast backbone (mbone)," IEEE Communications Magazine, vol. 35, pp. -, June 1997.

Abstract: The multicast backbone (MBone) is a network overlaying the global Internet and designed to support multipoint applications. In this article, the authors first give an overview of the development and architecture of the current MBone. One important characteristic of the MBone is its reliance on IP multicast which allows receivers to join and leave groups asynchronously. The authors describe the Mlisten data collection tool that was created to provide a mechanism for capturing information about when members join and leave a multicast group. Using data collected with Mlisten, the authors present statistics about some of the MBone sessions they monitored. Results are provided for key parameters including multicast participant interarrival times and participant durations, multicast tree size and characteristics, and intersession relationships. Collecting data about MBone usage can improve our understanding of how multicast communication and real-time protocols are being used today.
Keywords: Multicast Group Behavior;Multicast Backbone;Mbone; Mlisten

Arup Acharya, Rajiv Dighe, and Furquan Ansari, "Ip switching over fast ATM cell transport (IPSOFACTO): Switching multicast flows," in Proc. of Global Internet (Globecom), (Phoenix, Arizona), Nov. 1997.

Abstract: This paper describes a method for mapping IP flows to ATM switches. No signaling is necessary to setup a path through ATM switches. Switch controllers run a IP routing protocol and execute IP forwarding. The IPSOFACTO component is responsible for mapping a IP flow to a switched path. The focus of this paper is primarily on switching IP multicast flows.
Keywords: IP multicast; IPSOFACTO; IP switching

T. Ballardie, "Core based trees (CBT) multicast routing architecture," Request for Comments (Experimental) 2201, Internet Engineering Task Force, Sept. 1997.

Abstract: CBT is a multicast routing architecture that builds a single delivery tree per group which is shared by all of the group's senders and receivers. Most multicast algorithms build one multicast tree per sender (subnetwork), the tree being rooted at the sender's subnetwork. The primary advantage of the shared tree approach is that it typically offers more favourable scaling characteristics than all other multicast algorithms. The CBT protocol is a network layer multicast routing protocol that builds and maintains a shared delivery tree for a multicast group. The sending and receiving of multicast data by hosts on a subnetwork conforms to the traditional IP multicast service model.

T. Ballardie, "Core based trees (CBT version 2) multicast routing - protocol specification -," Request for Comments (Experimental) 2189, Internet Engineering Task Force, Sept. 1997.

Abstract: This document describes the Core Based Tree (CBT version 2) network layer multicast routing protocol. CBT builds a shared multicast distribution tree per group, and is suited to inter- and intra-domain multicast routing. CBT may use a separate multicast routing table, or it may use that of underlying unicast routing, to establish paths between senders and receivers. The CBT architecture is described in RFC 2201.

T. Ballardie, "A multicast 'traceroute' facility for shared trees," Internet Draft, Internet Engineering Task Force, Oct. 1997. Work in progress.

Abstract: ''mtrace'' [1] is a very useful tool for diagnosing IP multicast rout- ing problems, such as multicast routing loops and misconfigured mul- ticast routers, associated with source-rooted RPF-based distribution trees. For ''mtrace'' to be useful in a shared tree environment (e.g. PIM [2], CBT [3], GUM [4]) its behaviour must be modified. This draft speci- fies that behaviour, which is sufficiently general to be applicable to all shared tree types and operating modes. A new ''wildcard'' mode of behaviour is also described, which allows a trace of a complete shared tree. Authentication is recommended in this mode because of its potential as a vehicle for denial of service attacks. It is intended that this draft become a document of the Mbone Deploy- ment (mboned) working group of the IETF. Therefore, comments are solicited and should be sent to mboned's mailing list and/or the author.

S. Bradner, A. Mankin, A. Romanow, and V. Paxson, "IETF criteria for evaluating reliable multicast transport and application protocols," Internet Draft, Internet Engineering Task Force, May 1998. Work in progress.

Abstract: This memo describes the procedures and criteria for reviewing reliable multicast protocols within the Transport Area (TSV) of the IETF. Within today's Internet, important applications exist for a reliable multicast service. Some examples that are driving reliable multicast technology are collaborative workspaces (such as whiteboard), data and software distribution, and (more speculatively) web caching protocols. Due to the nature of the technical issues, a single commonly accepted technical solution that solves all the demands for reliable multicast is likely to be infeasible [RMMinutes 1997]. A number of reliable multicast protocols have already been developed to solve a variety of problems for various types of applications. [Floyd97] describes one widely deployed example. How should these protocols be treated within the IETF and how should the IETF guide the development of reliable multicast in a direction beneficial for the general Internet? The TSV Area Directors and their Directorate have outlined a set of review procedures that address these questions and set criteria and processes for the publication as RFCs of Internet-Drafts on reliable multicast transport protocols.

S. Casner and B. Fenner, "A ''traceroute'' facility for IP multicast.," Internet Draft, Internet Engineering Task Force, Dec. 1997. Work in progress.

Abstract: This draft describes the IGMP multicast traceroute facility. As the deployment of IP multicast has spread, it has become clear that a method for tracing the route that a multicast IP packet takes from a source to a particular receiver is absolutely required. Unlike unicast traceroute, multicast traceroute requires a special packet type and implementation on the part of routers. This specification describes the required functionality. This document is a product of the Inter-Domain Multicast Routing working group within the Internet Engineering Task Force. Comments are solicited and should be addressed to the working group's mailing list at and/or the author(s).

Sung Jin Chung, Sung Pil Hong, and Hong Suk Huh, "A fast multicast routing algorithm for delay-sensitive applications," in Proc. of Global Internet (Globecom), (Phoenix, Arizona), Nov. 1997.

Abstract: We propose a heuristic algorithm for delay-constrained minimum cost multicast routing in the packet-switched networks. The algorithm is computationally efficient since, unlike previous heuristics, it does not rely on any enumerative step that generates a set of delay-bounded paths between node pairs and chooses a minimum cost path. An extensive computational experiment is done on wide varieties of Waxman's networks including relatively large and dense instances. For small and sparse networks, the algorithm can find near-optimal multicast trees. Furthermore even when the network size grows, the quality of multicast tree does not seem to deteriorate while the computation time remains quite moderate.
Keywords: multicast; delay bound; Lagrangian relaxation; Waxman's network

D. Chouinard, "SOCKS V5 UDP and multicast extensions to facilitate multicast firewall traversal," Internet Draft, Internet Engineering Task Force, Nov. 1997. Work in progress.

Abstract: This proposal creates a mechanism for managing the ingress or egress of IP multicast through a firewall. It does this by defining extensions to the existing SOCKS V5 protocol [RFC-1928], which provides a framework for doing user-level, authenticated firewall traversal of unicast TCP and UDP traffic. However, because the current UDP support in SOCKS V5 has scalability problems as well as other deficiencies - and these need to be addressed before multicast support can be achieved - the extensions are defined in two parts: Base-level UDP extensions, and Multicast UDP extensions. Using the SOCKS framework for managing multicast flows in/out of an organization, offers numerous security advantages over what is possible with a conventional firewall approach. These are spelled out in the draft.

S. Deering, "Protocol independent multicast-sparse mode (PIM-SM): protocol specification," Request for Comments (Experimental) 2117, Internet Engineering Task Force, June 1997. (Obsoleted by RFC2362).

Abstract: This document describes a protocol for efficiently routing to multicast groups that may span wide-area (and inter-domain) internets. This document is the product of the Inter-Domain Multicast Routing Working Group of the IETF.

D. Estrin, M. Handley, and D. Thaler, "The internet multicast address allocation architecture," Internet Draft, Internet Engineering Task Force, Dec. 1997. Work in progress.

Abstract: This document proposes a multicast address allocation architecture for the Internet. The architecture is three layered, comprising a client->server protocol, an intra- domain protocol and an inter-domain protocol.

D. Estrin, M. Handley, D. Thaler, and S. Kumar, "The multicast address set claim (MASC) protocol," Internet Draft, Internet Engineering Task Force, Nov. 1997. Work in progress.

Abstract: The MASC protocol is used by a node (typically a router) to claim one or more sets of addresses (''address sets'') from which Multicast Address Allocation Servers (MAAS's) within its domain will allocate group addresses to hosts. Each address set has an associated lifetime, and is chosen out of a larger address set with a lifetime at least as long, in a manner such that address sets are aggregatable. At any time, each MASC node will typically be advertising several address sets with different lifetimes and scopes allowing MAAS's to choose appropriate addresses for their clients.

A. Emberson, "TFTP multicast option," Request for Comments (Experimental) 2090, Internet Engineering Task Force, Feb. 1997.

Abstract: This document describes a new TFTP option. This new option will allow the multiple clients to receive the same file concurrently through the use of Multicast packets.

B. Fenner, "Domain wide multicast group membership reports," Internet Draft, Internet Engineering Task Force, Nov. 1997. Work in progress.

Abstract: When running a multi-level multicast routing protocol, upper layers need to know about group memberships in lower layers in a protocol-independent fashion. Domain Wide Multicast Group Membership Reports allow this information to be learned in a fashion similar to IGMP[Fenn97] at the domain level. This document is a product of the IDMR working group within the Internet Engineering Task Force. Comments are solicited and should be addressed to the working group's mailing list at and/or the author.

W. Fritsch and H. Seifert, "Dynamical routing (unicast and multicast) for the ipv6 protocol," Internet Draft, Internet Engineering Task Force, Nov. 1997. Work in progress.

Abstract: Future communication networks will be based more and more on a dynamically changing network topology. Therefore it is advantageous, to have routing mechanisms, which will dynamically adapt their routing decisions to these topology changes. This document describes a set of network protocols, which realize such a dynamical routing of unicast and multicast packets within communication networks based on IPv6. All used routing algorithms will be immediately executed at the occurrence of any topology changes and will therefore have already complete routing information at the receipt of data packets. For the unicasting the Shortest Path First (SPF) routing algorithm has be chosen. This algorithm calculates the shortest, and therefore the optimal routing paths within the routing area, by which it is sufficient for a router, to compute a single routing tree for the whole area. For the multicasting the Minimum Spanning Tree (MST) routing algorithm has been chosen. This distributed algorithm prevents the occurrence of endless routing loops, offers for distributed Address Groups nearly optimal results in saving network bandwidth, and needs also only a single routing tree for the whole area. This version 02 of the draft mainly corrects some minor errors of version 01.

M. Handley, "Multicast address allocation protocol (AAP)," Internet Draft, Internet Engineering Task Force, Dec. 1997. Work in progress.

Abstract: The document defines a Multicast Address Allocation Protocol (AAP) that forms a part of a larger multicast address allocation architecture currently being defined. AAP addresses the specific issue of intra-domain multicast address allocation between multicast address allocation servers.

M. Handley, "Multicast-scope zone announcement protocol (MZAP)," Internet Draft, Internet Engineering Task Force, Dec. 1997. Work in progress.

Abstract: This document defines a protocol, the Multicast-Scope Zone Announcement Protocol (MZAP), for discovering the multicast administrative scope zones that are relevant at a particular location. MZAP also provides mechanisms whereby two common misconfigurations of administrative scope zones can be discovered.

M. Handley and J. Crowcroft, "Network text editor (NTE) a scalable shared text editor for MBone," ACM Computer Communication Review, vol. 27, pp. 197-208, Oct. 1997. ACM SIGCOMM'97, Sept. 1997.

Abstract: IP Multicast, Lightweight Sessions and Application Level Framing provide guidelines by which multimedia conferencing tools can be designed, but they do not provide specific solutions. In this paper, we use these design principles to guide the design of a multicast based shared editor, and examine the consequences of taking a loose consistency approach to achieve good performance in the face of network failures and losses.

K. A. Hua and S. Sheu, "Skyscraper boradcasting: A new boradcasting scheme for metropolitan video-on-demand systems," ACM Computer Communication Review, vol. 27, pp. 89-100, Oct. 1997. ACM SIGCOMM'97, Sept. 1997.

Abstract: We investigate a novel multicast technique, called Skyscraper Broadcasting (SB), for video-on-demand applications. We discuss the data fragmentation technique, the broadcasting strategy, and the client design. We also show the correctness of our technique, and derive mathematical equations to analyze its storage requirement. To assess its performance, we compare it to the latest designs known as Pyramid Broadcasting (PB) and Permutation-Based Pyramid Broadcasting (PPB). Our study indicates that PB offers excellent access latency. However, it requires very large storage space and disk bandwidth at the receiving end. PPB is able to address these problems. However, this is accomplished at the expense of a larger access latency and more complex synchronization. With SB, we are able to achieve the low latency of PB which using only 20 required by PPB.

Mike Hurwicz, "Multicast to the masses," Byte, pp. 93-97, June 1997.

Abstract: The IP multicast standard is ready, but the infrastructure isn't. Yet.
Keywords: IP multicast; DVMRP; RTP

IP Multicast Initiative, "Higher level protocols used with IP multicast," white paper, IP Multicast Initiative, Campbell, CA, Feb. 1997.

Abstract: An introduction to selected protocols used with IP Multicast to support multimedia and reliable data transmission. This document provides a brief technical overview of several higher level protocols used with IP Multicast. First, protocols that have been developed to support real-time multimedia delivery and Quality-of-Service (QoS) specifiers for multicast and unicast network services are presented. These include the Real-time Transport Protocol (RTP), the control protocol (RTCP) that works in conjunction with RTP, the resource reservation protocol (RSVP), and the real-time streaming protocol (RTSP). Quality-of-service routing is briefly considered. Next, reliable IP Multicast protocols, an emerging standards area, are discussed. Lastly, group setup protocols are introduced. The protocols described in this paper are at different levels of maturity.
Keywords: IP multicast; RTP; RSVP; RTSP; reliable multicast; IGMP; survey

IP Multicast Initiative (IPMI), "How IP multicast works," white paper, IP Multicast Initiative (IPMI), Campbell, CA, Feb. 1997.

Abstract: This document provides a technical introduction to IP Multicast concepts and technical features. It discusses the requirements for IP Multicast delivery, addressing and host group management, and approaches to multicast routing. Some familiarity with IP is assumed. If you are an engineer interested in evaluating or implementing IP Multicast, an understanding of the concepts in this document will help you. You may also be interested in other documents in this white paper series which are available from
Keywords: IP multicast; tutorial

IP Multicast Initiative (IPMI), "Implementing IP multicast in different network infrastructures," white paper, IP Multicast Initiative (IPMI), Campbell, CA, Apr. 1997.

Abstract: There are a number of underlying network infrastructures over which TCP/IP networks can be overlaid. These can be categorized into three classifications: 1. Backbone WAN infrastructures 2. Campus and Premise LAN infrastructures 3. Last mile switched WAN connections Backbone WAN infrastructures include satellite, frame relay, SMDS, ATM and the Internet. Campus and premise LAN infrastructures include both shared LANs and switched LANs. Last mile switched WAN connections include dial-up modem and ISDN. These different network infrastructures accommodate IP Multicast support with differing amounts of ease. For each, this document provides a description of the service, including any special mechanisms for enabling IP Multicast, and network engineering considerations.
Keywords: IP multicast; routing; tutorial

IP Multicast Initiative (IPMI), "Introduction to IP multicast routing," white paper, IP Multicast Initiative, Campbell, CA, Feb. 1997.

Abstract: This document provides a high-level technical overview of IP Multicast routing protocols. If you are an engineer interested in evaluating or implementing IP Multicast for your organization, product or service, this document will help you understand the distinguishing features of the routing protocols. It assumes you have a conceptual understanding of IP Multicast addressing, group management and IP routing. If you are unfamiliar with these, we recommend you first read the IP Multicast Initiative white paper 'How IP Multicast Works'.
Keywords: IP multicast; tutorial

IP Multicast Initiative (IPMI), "IP multicast backgrounder," white paper, IP Multicast Initiative (IPMI), Campbell, CA, Feb. 1997.

Abstract: This document provides an executive introduction to IP multicast. It presents the basic concept, highlights its benefits, and provides suggestions for getting started. Whether you're in a TCP/IP-based enterprise or are a vendor interested in implementing or taking advantage of IP multicast within your product or service, this document will help you.
Keywords: IP multicast; tutorial

Gunnar Karlsson, "Layered error-control coding for IP multicast," in Third International Workshop on High Performance Protocol Architectures, HIPPARCH '97 (Per Gunningberg and Christian Huitema, eds.), (Uppsala, Sweden), pp. B2:1-9, June 1997.

Abstract: Layered source coding was first proposed about ten years ago and is now widely accepted as a means to transfer real-time video and audio in packet-switched networks. In this paper we propose layering also for the transfer of redundancy information given by error-control coding. The aim is that each receiver should be able to decide on the amount of redundancy needed in order to reach a desired quality level of the received information. In order to make this decision, we introduce a channel distortion-rate curve: Given a rate of redundancy and a loss rate in the network, there will be residual (not correctable) losses which contribute to the signal distortion. For a specified total rate of the transfer, the question is therefore how it should be split between the source and redundancy rates. These ideas are illustrated by a simple convolutional coding method for IP multicast.
Keywords: real-time video; error-control coding; packet loss; distortion; IP multicast

M. Lim and D. Kim, "IP extension for reliable multicast," Internet Draft, Internet Engineering Task Force, Nov. 1997. Work in progress.

Abstract: This memo presents IP extension for recovering multicast packets from congestion. Dropped packets can be recovered far faster by IP routers with extension of this memo than by group member end-hosts. Because necessary interactions are limited among adjacent routers, this scheme substantially reduces overall signaling overhead among group members for packet recovery.

Longsong Lin, Lih Chyau Wuu, , and Cheng Chin Lin, "Minimum hop-count multicast algorithms for reliable multiple-stream communications," in Proc. of Global Internet (Globecom), (Phoenix, Arizona), Nov. 1997.

Abstract: This article is concerned with the multicast problem in which many destinations simutaneously request mutiple data streams from a source, and require them to be delivered reliably and in minimum hop distance. The basic idea is to induce a sub-graph from a given network using the breadth-first-search principle, and then based on this sub-graph, to construct the minimum hop-count multicast tree. After that, a bandwidth assignment algorithm and a level-by-level acknowledgment method are employed to enforce the reliable, concurrent delivery of the multiple streams. It is shown, through analysis and simulations on a class of random graphs, that our approach significantly reduces the number of transmissions and average packet delay.
Keywords: Multicast algorithm; multimedia communication; reliable protocol; network algorithm; reliable multicast

D. Meyer, "Administratively scoped IP multicast," Internet Draft, Internet Engineering Task Force, Nov. 1997. Work in progress.

Abstract: This document defines the ''administratively scoped IPv4 multicast space'' to be the range to In addition, it describes a simple set of semantics for the implementation of Administratively Scoped IP Multicast. Finally, it provides a mapping between the IPv6 multicast address classes [RFC1884] and IPv4 multicast address classes. This memo is a product of the MBONE Deployment Working Group (MBONED) in the Operations and Management Area of the Internet Engineering Task Force. Submit comments to or the author.

D. Meyer, "Some issues for an inter-domain multicast routing protocol," Internet Draft, Internet Engineering Task Force, Nov. 1997. Work in progress.

Abstract: The IETF's Inter-Domain Multicast Routing (IDMR) working group has produced several multicast routing protocols, including Core Based Trees [CBT] and Protocol Independent Multicasting [PIMARCH]. In addition, the IDMR WG has formalized the specification of the Distance Vector Multicast Routing Protocol [DVMRP]. Various specifications for protocol inter-operation have also been produced (see, for example, [THALER96] and [PIMMBR]). However, none of these protocols seems ideally suited to the inter-domain routing case; that is, while these protocols are appropriate for the intra-domain routing environment, they break down in various ways when applied in to the multi-provider inter-domain case. This document considers some of the scaling, stability and policy issues that are of primary importance in a inter-domain, multi- provider multicast environment.

K. McCloghrie, D. Farinacci, and D. Thaler, "IP multicast routing MIB," Internet Draft, Internet Engineering Task Force, Dec. 1997. Work in progress.

Abstract: This memo defines an experimental portion of the Management Information Base (MIB) for use with network management protocols in the Internet community. In particular, it describes managed objects used for managing IP Multicast Routing [5], independent of the specific multicast routing protocol [6,7,8,9,10] in use. Managed objects specific to particular multicast routing protocols are specified elsewhere.

K. McCloghrie, D. Farinacci, and D. Thaler, "Protocol independent multicast MIB," Internet Draft, Internet Engineering Task Force, Dec. 1997. Work in progress.

Abstract: This memo defines an experimental portion of the Management Information Base (MIB) for use with network management protocols in the Internet community. In particular, it describes managed objects used for managing the Protocol Independent Multicast (PIM) protocol [5,6,7,8]. This MIB module is applicable to IP multicast routers which implement PIM.

S. Mittra, "Iolus: A framework for scalable secure multicasting," ACM Computer Communication Review, vol. 27, pp. 277-288, Oct. 1997. ACM SIGCOMM'97, Sept. 1997.

Abstract: As multicast applications are deployed for mainstream use, the need to secure multicast communications will become critical. Multicast, however, does not fit the point-to-point model of most network security protocols which were designed with unicast communications in mind. As we will show, securing multicast (or group) communications is fundamentally different from securing unicast (or paired) communications. In turn, these differences can result in scalability problems for many typical applications. In this paper, we examine and model the differences between unicast and multicast security and then propose Iolus: a novel framework for scalable secure multicasting. Protocols based on Iolus can be used to achieve a variety of security objectives and may be used either to directly secure multicast communications or to provide a separate group key management service to other

T. Maufer and C. Semeria, "Introduction to IP multicast routing," Internet Draft, Internet Engineering Task Force, Oct. 1997. Work in progress.

Abstract: The first part of this paper describes the benefits of multicasting, the MBone, Class D addressing, and the operation of the Internet Group Management Protocol (IGMP). The second section explores a number of different techniques that may potentially be employed by multicast routing protocols: o Flooding o Spanning Trees o Reverse Path Broadcasting (RPB) o Truncated Reverse Path Broadcasting (TRPB) o Reverse Path Multicasting (RPM) o ''Shared-Tree'' Techniques The third part contains the main body of the paper. It describes how the previous techniques are implemented in multicast routing protocols available today (or under development). o Distance Vector Multicast Routing Protocol (DVMRP) o Multicast Extensions to OSPF (MOSPF) o Protocol-Independent Multicast - Dense Mode (PIM-DM) o Protocol-Independent Multicast - Sparse Mode (PIM-SM) o Core-Based Trees (CBT)

T. Nishida and A. Bakre, "IP multicast over ATM networks with cut-through forwarding for inter LIS traffic," Internet Draft, Internet Engineering Task Force, Dec. 1997. Work in progress.

Abstract: This document proposes a scheme for IP multicasting in ATM networks, which can achieve cut-through forwarding for inter LIS multicast traffic using ATM protocols.

J. Nonnenmacher, E. Biersack, and D. Towsley, "Parity-based loss recovery for reliable multicast transmission," ACM Computer Communication Review, vol. 27, pp. 289-300, Oct. 1997. ACM SIGCOMM'97, Sept. 1997.

Abstract: We investigate how FEC (Forward Error Correction) can be combine with ARQ (Automatic Repeat Request) to achieve scalable reliable multicast transmission. We consider the two scenarios where FEC is introduced as a transparent layer underneath a reliable multicast layer that uses ARQ, and where FEC and ARQ are both integrated into a single layer that uses the retransmission of parity data to recover from the loss of original data packets. To evaluate the performance improvements due to FEC, we consider different types of loss behaviors (spatially or temporally correlated loss, homogeneous or heterogeneous loss) and loss rates for up to 10^6 receivers. Our results show that introducing FEC as a layer below ARQ can improve multicast transmission efficiency and scalability and that there are substantial additional improvements when the two are integrated.

Rolf Oppliger and Andres Albanese, "Participant registration, validation, and key distribution for large-scale conferencing systems," IEEE Communications Magazine, vol. 35, pp. -, June 1997.

Abstract: DiRK (Distributed Registration and Key distribution) is a technique that can be used in large-scale conferencing systems to handle participant registration, validation, and key distribution in a decentralized and distributed way. The basic idea is to distinguish active and passive participants in a conference session, and to have the active participants assist the session holder to register participants and distribute session keys accordingly. This article introduces the basic principles of DiRK and overviews a prototype implementation for the Internet Multicast Backbone (MBone). As an exemplary application, the article also addresses the use of DiRK in distance education and teleteaching.
Keywords: DiRK; Participant Registration;Validation; Key Distribution; Conferencing Systems

J. Ott, C. Bormann, and N. Seifert, "MTP/SO: self-organizing multicast," Internet Draft, Internet Engineering Task Force, Dec. 1997. Work in progress.

Abstract: Multiparty cooperative applications have recently received much attention, as has the multicasting of datagrams in the internet. The internet datagram multicasting mechanism is not reliable, often requiring a higher level protocol to achieve the level of reliability required for an application. Much of the extensive work on reliable multicast protocols has assumed relatively stable groups that need to ensure that all messages are received by all members of this well-defined group. Recently, work on loosely coupled teleconferencing has directed attention to a class of multicast applications that scale up to an extent where this assumption is no longer practical. An interesting multicast transport protocol is defined in RFC 1301. MTP provides globally ordered, receiver reliable, rate controlled and atomic transfer of messages to multiple recipients. A revised, more practical version of MTP, the Multicast Transport Protocol MTP-2 has been in use for some time. Self-Organizing Multicast, MTP/SO, uses MTP-2 as a basis and adds spontaneous self-organization of the members of the group into local regions. Scalability is increased by providing passive group joining and local retransmission of lost packets. This version of the document is not yet complete but contains most of the vital parts.

Z. Ortiz, G. N. Rouskas, and H. G. Perros, "Scheduling of multicast traffic in tunable-receiver WDM networks with non-negligible tuning latencies," ACM Computer Communication Review, vol. 27, pp. 301-310, Oct. 1997. ACM SIGCOMM'97, Sept. 1997.

Abstract: We consider the problem of supporting multipoint communication at the media access control (MAC) layer of broadcast-and-select WDM networks. We first show that bandwidth consumption and channel utilization arise as two conflicting objectives in the design of scheduling algorithms for multicast traffic in this environment. We then present a new technique for the transmission of multicast packets, based on the concept of a virtual receiver, a set of physical receivers which behave identically in terms of turning. We also show that the number k of virtual receivers naturally captures the tradeoff between channel utilization and bandwidth consumption. Our approach decouples the problem of determining the virtual receivers from the problem of scheduling packet transmissions, making it possible to employ existing scheduling algorithms that have been shown to successfully hide the effects of tuning latency. Consequently, we focus on the problem of optimally selecting the virtual receivers, and we prove that it is NP-complete. Finally, we present four heuristics of varying degrees of complexity for obtaining virtual receivers that provide a good balance between the two conflicting objectives.

Colin Perkins and Jon Crowcroft, "Real-time audio and video transmission of IEEE GLOBECOM '96 over the internet," IEEE Communications Magazine, vol. 35, pp. 30-33, Apr. 1997.

Abstract: This article is about the experiences of the authors in transmitting the proceedings of some events at IEEE GLOBECOM '96 in London, England, in the week of November 17-22, 1996. Live video and audio of all the events in the Churchill Auditorium of the Queen Elizabeth II Conference Center were captured and transmitted, in real time, as well as stored and transmitted later, for remote participants in three continents, over the Internet. Two independent systems were used simultaneously, one supplied by researchers from NTT Laboratories in Japan and the other by researchers from University College London. The former system is based on a server model of distribution, while the latter is based on the use of network-level packet multicast. Both systems employ compression algorithms, so the network capacity requirement in each case was on the order of 100 kb/s to 200 kb/s total, thus enabling remote participants without very high-end network connectivity to take part. Receivers only need software for a PC running most popular versions of Windows or a UNIX workstation to be able to receive either type of transmission, or to retrieve the recorded sessions from NTT Laboratories' servers. The multimedia transmission was carried over carefully engineered links that traversed many different subnet technologies, including point-to-point circuits, SMDS networks, ATM networks, and fast Ethernet switches. This was both to give a high level of assurance that the traffic would not experience too much interference from other traffic at the site and elsewhere, and to ensure very low packet store and forward delays. The system ran for four days continuously, and was generally very successful. In the future, it should be possible to have remote paying attendees.
Keywords: IEEE globecom; 1996

B. Patel and M. Shah, "Multicast address allocation extensions options," Internet Draft, Internet Engineering Task Force, Nov. 1997. Work in progress.

Abstract: This document describes host configuration options that may be used by multicast address allocation protocols[3]. The options include critical information such as the multicast address of the multicast address allocation server(s) and a list of multicast scopes supported by respective servers. These options are designed to work with the extensions to DHCP [1] servers to support multicast address allocation (described in a separate draft), however, their use may not be limited to the above protocol.

B. Patel and M. Shah, "Multicast address allocation extensions to the dynamic host configuration protocol," Internet Draft, Internet Engineering Task Force, Nov. 1997. Work in progress.

Abstract: The Dynamic Host Configuration Protocol (DHCP) provides a framework for passing configuration information to hosts on a TCP/IP network. The multicast extensions to DHCP add additional capability of dynamic allocation of the multicast addresses and additional configuration options.

R. Ramanathan, "Multicast support for nimrod : Requirements and solution approaches," Request for Comments (Informational) 2102, Internet Engineering Task Force, Feb. 1997.

Abstract: Nimrod does not specify a particular solution for multicasting. Rather, Nimrod may use any of a number of emerging multicast techniques. This document identifies the requirements that Nimrod has of a solution for multicast support. This document is a product of the New Internet Routing and Addressing Working Group of the IETF.

M. Smirnow, H. Sanneck, D. Witaszek, L. Salgarelli, and A. Corghi, "Supporting IP multicast integrated services in ATM networks," Internet Draft, Internet Engineering Task Force, Nov. 1997. Work in progress.

Abstract: This memo presents an integrated, server-based mechanism for the efficient support of the IP Integrated Services (IIS) model in ATM networks, namely the Multicast Integration Server (MIS) architecture. Instead of viewing IP-ATM multicast address resolution and QoS support separately, the approach in this memo is to consider such issues in an integrated manner. In particular, the MIS architecture defines how a layer-3 setup protocol as RSVP can be mapped to and integrated with a layer-2 multicast address resolution protocol as EARTH - EAsy Multicast Routing THrough ATM clouds. With the use of EARTH, several ATM point-to-multipoint connections with different QoS parameters can be associated to a single IP multicast address. An RSVP server (RSVP-S) within the MIS is used to distribute RSVP messages inside the ATM cloud and to set the corresponding QoS state in the address resolution table of EARTH (setup protocol mapping). In addition, this memo defines a quantized heterogeneity model which supports, together with the MIS, advanced IIS features as QoS heterogeneity and dynamic QoS changes in IP-ATM networks.

R. Talpade and M. Ammar, "Multicast server architectures for MARS-based ATM multicasting.," Request for Comments (Informational) 2149, Internet Engineering Task Force, May 1997.

Abstract: Two basic approaches exist for the intra-subnet (intra-cluster) multicasting of IP packets. One makes use of a mesh of point to multipoint VCs (the 'VC Mesh' approach), while the other uses a shared point to multipoint tree rooted on a Multicast Server (MCS). This memo provides details on the design and implementation of an MCS, building on the core mechanisms defined in RFC 2022. It also provides a mechanism for using multiple MCSs per group for providing fault tolerance. This document is the product of the Internetworking Over NBMA Working Group of the IETF.

M. Tatham and B. Briscoe, "End to end aggregation of multicast addresses," Internet Draft, Internet Engineering Task Force, Dec. 1997. Work in progress.

Abstract: This paper presents an approach for solving the inherent problem with multicast routing scalability - by co-operation between end-systems and the network. We introduce an extremely efficient, elegant way to name arbitrary sized inter-meshed aggregations of multicast addresses. This is done in such a way that it is easy to calculate how to change the name to encompass many more related names. We describe how these aggregate names could be used anywhere in place of the set of addresses to which they refer, not by resolving them into multiple operations, but by a single bulk action throughout the routing tree, and in session descriptions potentially including those for reservations. Initial aggregation in end-systems might only reduce the problem by an order of magnitude, but it is believed that this will provide sufficient structure for routers to be able to recognise further aggregation potential. To improve the chances of router aggregation, address set allocation schemes must fulfil certain criteria that are laid down in this paper.

X. Rex Xu, Andrew C. Myers, Hui Zhang, and Raj Yavatkar, "Resilient multicast support for continuous-media applications," in Proc. International Workshop on Network and Operating System Support for Digital Audio and Video (NOSSDAV), (St. Louis, Missouri), May 1997.

Abstract: The IP multicast delivery mechanism provides a popular basis for delivery of continuous media to many participants in a conferencing application. However, the best-effort nature of multicast delivery results in poor playback quality in the presence of network congestion and packet loss. Contrary to widespread belief that the real-time nature of continuous media applications precludes the possibility of recovery of lost packets using retransmissions, we have found that these applications offer an interesting tradeoff between the desired playback quality and the desired degree of interactivity. In particular, we propose a new model of multicast delivery called resilient multicast in which each receiver in a multicast group can decide its own tradeoff between reliability and real-time requirements. To be effective, error recovery mechanisms in such a model need to be both fast (due to the real-time constraint) and have a low overhead (due to high volume of continuous media data). We have designed a resilient multicast protocol called STORM (STructure-Oriented Resilient Multicast) in which senders and receivers collaborate to recover from lost packets using two key ideas. First, group participants self-organize themselves into a distribution structure and use the structure to recover lost packets from adjacent nodes. Second, the distribution structure is dynamic and a lightweight algorithm is used to adapt the structure to changing network traffic conditions and group membership. We have implemented STORM in both VAT and a packet level simulator. Experimental results using both the MBONE and a simulation model demonstrate the effectiveness of our approach.
Keywords: reliable multicast; packet audio; packet loss

George Xylomenos and George C. Polyzos, "IP multicast for mobile hosts," IEEE Communications Magazine, vol. 35, pp. -, Jan. 1997.

Abstract: We present alternative designs for efficiently supporting multicast for mobile hosts on the Internet. Methods for separately supporting multicasting and mobility along with their possible interactions are briefly described, and then various solutions to the combined problem are explored. We examine three different multicast delivery mechanisms and compare them based on their efficiency and impact on host protocol software.
Keywords: IP Multicast; Mobile Hosts

Tanja Zseby, "Support for IP multicast over UNI 3.x: Link layer extension," diplomarbeit, Technical University Berlin, Berlin, Germany, Sept. 1997.

Abstract: This document describes the development and implementation of an extension to the FORE ATM device driver (version 4.1.0) to support the delivery of IP Multicast data over UNI 3.x ATM connections. The device driver extension provides a capable basis for the implementation of Multicast Address Resolution Protocols (MARP) like MARS and EARTH. Since the manual modification of MARP table entries is supported, the extension can be used to send multicast data even without a MARP.
Keywords: IP Multicast; ATM; UNI 3.1; EARTH; MARS; ATM device driver

Salama, H.F., et al, Evaluation of Multicast Routing Algorithms for Real-Time Communication on High-Speed Networks, to appear in IEEE Journal of Selected Areas in Communications , 1997

M. Grossglauser and K.K. Ramakrishnan, "SEAM: A scheme for scalable and efficient ATM multipoint-to-multipoint communication", appeared in Infocom'97.

Cost, Delay, and Delay Variation Conscious Multicast Routing, USA , Technical Report, North Carolina State University.

Scheduling of Multicast Traffic in Tunable-Receiver WDM Networks with Non-Negligible Tuning Latencies. George N. Rouskas, Zeydy Ortiz-Laureano and Harry G. Perros. Technical Report, (TR-97-01), North Carolina State University, USA