Networking issues in IP multicast over satellite

Abstract

This paper describes the issues that arise when using satellites for IP multicast, with the emphasis on multicast protocols and how their implementation depends on the satellite communications platform.Various link layer standards such as DVB-S, DVB-RCS and ATM can be used in satellites with onboard processing, and applied to meet user and network requirements for IP multicast. The paper provides an overview of the networking issues and their interactions. Specifically, we show how multicast networking protocols have to be modified to take into account the satellite link characteristics: these protocols include IGMP, multicast routing protocols and reliable multicast protocols. We also discuss how security systems support IP multicast.KEYWORDS: satellite, multicast, security, Internet, IP, QoS, DVB, ATM, IGMP INTRODUCTIONIn recent years, much research and development has been carried out in satellite networking technologies and applications. Some network technologies that have received significant attention for broadband services are ATM over satellite, Digital Video Broadcasting -Satellite (DVB-S) and DVB Interactive Return Channel via Satellite (DVB-RCS), together with IP for Internet access and interconnection. In terms of applications, the work has focused not only on traditional best-effort services such as file transfer and world-wide web applications, but also on support for real-time multimedia and multicast applications with specific quality of service (QoS) requirements. The success of satellite digital broadcast services (for TV and radio) and the asymmetric nature of IP traffic flow have been combined to result in satellite systems that support high-speed Internet access.

IGMP behaviour in multicast over satellite

“…Whereas in case of satellite network different ground stations are not aware of each other. In case, huge number of multicast receivers are there in a satellite system (about 105) then IGMP traffic flooding could be caused by multiple IGMP Reports [5]. There could two scenarios in this situation.…”

“…It could result in IGMP flooding over satellite which could result in unreliable network design [5]. This paper is based on a simulation of multicast application (video conferencing) among terrestrial LANs interconnected via fixed GEO satellite.…”

IMS-based IP Multicast Service Delivery over Satellite Network

“…Paper [3] highlights these important issues and shows how multicast networking protocols have to be modified to take into account the satellite link characteristics relaying on IGMP (Internet Group Management Protocol), multicast routing protocols and reliable multicast protocols. It discusses also how security system is supported in IP multicast.…”

Integration of TESLA and FLUTE over satellite networks

“…Many satellite systems natively support IP multicast [1], allowing connected systems to take advantage of the widecoverage of most satellite down-link footprints. Furthermore, the cost of transmission is independent of the number of receivers; making multicast cost-effective, especially when low cost receive-only terminals are used.…”