Gap Analysis in IP Multicast Dissemination

IP multicast is increasingly seen as efficient mode of live content distribution in the Internet to significantly large subscriber bases. Despite its numerous benefits over IP unicast, multicast has not seen widespread deployment over modern networks. Network complexity and session discovery issues have plagued IP multicast since its inception. The Internet research community is in general agreement to move over to SSM (Source Specific Multicast).With IGMP v 3 (Internet Group Management Protocol) and SSM, the source discovery burden will rest with the end user. Channel discovery is one of the few stumbling blocks remaining to be solved for successful and widespread deployment of multicast. In an earlier work a DNS (Domain Name System) aware multicast session discovery architecture, mDNS, has been proposed which is distributed, hierarchical and globally scalable.This paper proposes to leverage the mDNS architecture by enabling multicast sessions to be tagged using geographical and spatial information based on the channel contents or service provider location. It further proposes automatic geo-coding of session registration information as the content provider registers session information with mDNS. It also provides necessary design changes and gives data models and data structures to support seamless location sensitive session retrieval as part of search query results to be furnished to the end user. The paper includes envisaged scenarios in which geo-tagging would enhance end user experience and would enable smarter query result generation.

In recent times, the demand for multicast communications is increasing, both from internet service providers and from the content, media providers or distributors. One of the main obstacles to the wider commercial deployment of internet protocol (IP) multicast is the lack of security for the content being transmitted through IP multicast and communication infrastructure underlying IP multicast. This paper presents a multi-party key computation (MKC) protocol which provides added security to IP multicast. The group key computation, in our protocol, involves multi-party computations using one-time pad and a secret sharing scheme. The proposed protocol is secure, efficient and compatible with IPSec.

In Mobile IP, the signaling traffic overhead will be too high since the new Care-of-Address (CoA) of the mobile node (MN) is registered all the way with the home agent (HA) whenever the MN has moved into a new foreign network. To complement Mobile IP in better handling local movement, several IP micro protocols have been proposed. These protocols introduce a hierarchical mobility management scheme, which divides the mobility into micro mobility and macro mobility according to whether the host's movement is intra-domain or inter-domain. Thus, the requirements on performance and flexibility are achieved, especially for frequently moving hosts. This paper introduces a routing protocol for multicast source mobility on the basis of the hierarchical mobile management scheme, which provides a unified global architecture for both uni- and multicast routing in mobile networks. The implementation of multicast services adopts an improved SSM (Source Specific Multicast) model, which combines the advantages of the existing protocols in scalability and mobility transparency. Simulation results show that the proposed protocol has better performance than the existing routing protocols for SSM source mobility.

Multicast Communications in Next-Generation Internet

Peer-to-peer (P2P) systems, which have attracted public attention, involve a number of directly connected "peers" exchanging various types of information among themselves. However, applications based on P2P systems generally generate a lot of traffic and require not only the resources of every peer (e.g., CPU, memory, and bandwidth) but also many network resources. We think the main problems of P2P systems can be solved using IP multicasting, which is becoming popular as an effective way to transfer streaming media over the network and can reduce network traffic and the load on a streaming server. We propose applying IP multicasting to P2P systems. After mentioning that almost every application can be improved by our proposal, we discuss which routing protocol is suitable. Finally, we show that we can get good results even when part of the network does not support IP multicasting.

The efficient support of the IP Integrated Services architecture (IIS) in ATM networks is nowadays a challenging research topic in the internetworking area. The integration of the two architectures needs the overcoming of the inconsistencies existing between their service models, in particular when considering multicast communications. The IIS architecture is based on the Resource Reservation Protocol (RSVP). IP multicast and RSVP rely on a receiver- oriented mode, where a receiver is not only capable of deciding whether to join or leave a multicast sessions, but it is also allowed to choose the associated QoS independently from the other participants. On the other hand, the ATM service model is sender-oriented: the originating node of a multipoint session is the only entity allowed to add or delete leaf nodes. In addition, the originating node sets the QoS of a session, which is unique for all the receivers. The IETF standard for IP multicast over ATM is the MARS model. Nevertheless this approach has been developed for best effort connections only. In this paper we present an extension to the MARS protocol n order to be integrated with the RSVP protocol for supporting QoS management. Within a logical IP Subnet, a Multicast Integration Server (MIS) is entitled of IP multicast address to ATM addressees resolution using the MARS protocol, and of QoS management using RSVP. In addition to the functionalities foreseen by the MARS specification, the MARS server within the MIS uses anew set of messages to inform the sender to a group about the QoS chosen by each receiver. An RSVP entity within the MIS is used to distribute RSVP messages within the LIS and to provide to the MARS the translation of the QoS level form IIS to ATM.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The Real-time Transport Object delivery over Unidirectional Transport protocol (ROUTE Protocol) is specified for robust delivery of application objects, including application objects with real-time delivery constraints, to receivers over a unidirectional transport. Application objects consist of data that has meaning to applications that use the ROUTE Protocol for delivery of data to receivers, for example, it can be a file, or a DASH or HLS segment, a WAV audio clip, etc. The ROUTE Protocol also supports low-latency streaming applications. The ROUTE Protocol is suitable for unicast, broadcast, and multicast transport. Therefore, it can be run over IP/UDP including multicast IP. ROUTE Protocol can leverage the features of the underlying protocol layer, e.g. to provide security it can leverage IP security protocols such as IPSec.

Despite the availability of high bandwidth Internet access for end-users, video broadcasting over the Internet is not widely spread. Multicast communication decreases the network load by eliminating redundancy of the data transfer. However IP multicast was never widely accepted by commercial Internet service providers (ISP). Existing solutions solving this problem, like MBONE tunneling, are not available for end-users accessing the Internet via xDSL or TV cable. Application layer multicast using peer-to-peer (P2P) overlay networks could solve the problem of sparse IP multicast support in the Internet. A limitation of this approach is the lack of standardized interfaces for existing IP multicast applications. We propose a solution, which bridges application layer multicast and IP multicast and uses a P2P (overlay) network to transport multicast data. Our solution - including a proof-of-concept prototype - enables video broadcasting over the Internet using existing IP multicast applications without requiring additional service deployment.

Seamless mobility support and efficient network resource utilization is the key to the performance of mobile multimedia services. Currently, the PMIP (Proxy Mobile-IP) and the IMS (IP Multimedia Subsystem) are considered as the primary means to this end, mostly focusing on unicast applications (e.g., voice over IP). In this paper, we extend the application scope to multicast services and propose a solution framework combining the PMIP with IP multicast. Specifically, we propose an extension of the PMIP (called PMIP-M) for a seamless handover of multicast services that use existing IP multicast protocols, where gradual IP multicast deployment is taken into account for practicality. That is, a user can start or continue to receive multicast service even when he migrates to a network without IP multicast capability. The performance of the proposed scheme is analyzed by extensive simulations.

Without doubt, multicast communication as a means for one-to-many or many-to-many delivery of data has become a hot topic in multimedia environments. A lot of people are interested in multicast: the research community, standards groups and Internet Service Providers (ISP) among them. Although IP multicast is a very good solution for Internetworking multimedia in many-to-many communications, there are still issues that have not been completely solved. Protocols are still evolving and new protocols are constantly coming up to solve these issues because that is the only way for making multicast become a true Internet service. The main goal of this chapter is to describe the evolution of IP multicast from the obsolete MBone (Multicast Backbone) and intra-domain multicast routing to the actual inter-domain multicast routing scheme. We will pay special attention to the challenges and problems that need to be solved, the problems that have been solved and the way they were solved. We will make a complete picture of the state of the art explaining the idea behind each protocol and how all those protocols work together.

IP multicast offers the scalable point-to-multipoint delivery necessary for using group communication applications on the Internet. However, the IP multicast service has seen slow commercial deployment by ISPs and carriers. The original service model was designed without a clear understanding of commercial requirements or a robust implementation strategy. The very limited number of applications and the complexity of the architectural design-which we believe is a consequence of the open service model-have deterred widespread deployment as well. We examine the issues that have limited the commercial deployment of IP multicast from the viewpoint of carriers. We analyze where the model fails and what it does not offer, and we discuss requirements for successful deployment of multicast services.

In this paper we present work in progress on extending multimedia conferencing standards to scalable, mobile multimedia group support based on SIP initiated Source Specific IP Multicast. We propose extensions of SIP for negotiating SSM sessions. SIP protocol specifications and semantics are compatibly extended without adding new SIP methods. We will introduce a multimedia communication software with distributed architecture as implementation reference. The software is built on a scalable video codec adaptive to heterogeneous network capacities.

Due to the complexity and poor scalability, IP Multicast has not been used on the Internet. Recently, Xcast6 -- a complementary protocol of IP Multicast has been proposed. However, the key limitation of Xcast6 is that it only supports small multicast sessions. To overcome this, we propose Xcast6 Treemap islands (X6Ti) -- a hybrid model of Overlay Multicast and Xcast6. In summary, X6Ti has many advantages: support large multicast groups, simple and easy to deploy on the Internet, no router configuration, no restriction on the number of groups, no multicast routing protocol and no group management protocol. Based on simulation, we compare X6Ti with IP Multicast and NICE protocols to show the benefits of our new model.

2 - IPv6 Multicasting

The fast development and deployment of the Internet and mobile communication has boosted personal computing and communication. The ever-increasing number of personal devices accessing the Internet demands IP mobility support ubiquitously. However, the current TCP/IP protocol suite is not able to fully support IP mobility, especially when real-time applications are concerned. This paper discusses the IP mobility support in general and IP multicast receiver mobility support in particular. The current Internet is capable of providing basic mobility support for IP multicast when mobile hosts act as IP multicast receivers. However, the worst case handover latency introduced by IP layer handover is usually unacceptable to the real-time applications running in the mobile receivers. In order to overcome this, we propose a Mobility Support Agent (MSA) architecture and a set of protocols to help achieve seamless IP multicast mobility. Our testbed runs IGMPv2 and PIM-SM. Measurements have shown that by using the MSA architecture, the handover latency introduced by the current multicast membership management protocols and multicast routing protocols is nearly negligible.