RFC 3754 (rfc3754) - Page 2 of 34
IP Multicast in Differentiated Services (DS) Networks
Alternative Format: Original Text Document
RFC 3754 IP Multicast in DS Networks April 2004 9.1. Simulation Scenario. . . . . . . . . . . . . . . . . . . 24 9.2. Simulation Results for Different Router Types. . . . . . 26 10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 31 11. References . . . . . . . . . . . . . . . . . . . . . . . . . . 31 11.1. Normative References . . . . . . . . . . . . . . . . . . 31 11.2. Informative References . . . . . . . . . . . . . . . . . 31 12. Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . 33 13. Full Copyright Statement . . . . . . . . . . . . . . . . . . . 34 1. Introduction This document discusses the problems of IP Multicast use in Differentiated Services (DS) networks, expanding on the discussion in RFC 2475 ("An Architecture of Differentiated Services"). It also suggests possible solutions to these problems, describes a potential implementation model, and presents simulation results. The "Differentiated Services" (DiffServ or DS) approach [1, 2, 3] defines certain building blocks and mechanisms to offer qualitatively better services than the traditional best-effort delivery service in an IP network. In the DiffServ Architecture [2], scalability is achieved by avoiding complexity and maintenance of per-flow state information in core nodes, and by pushing unavoidable complexity to the network edges. Therefore, individual flows belonging to the same service are aggregated, thereby eliminating the need for complex classification or managing state information per flow in interior nodes. On the other hand, the reduced complexity in DS nodes makes it more complex to use those "better" services together with IP Multicast (i.e., point-to-multipoint or multipoint-to-multipoint communication). Problems emerging from this fact are described in section 2. Although the basic DS forwarding mechanisms also work with IP Multicast, some facts have to be considered which are related to the provisioning of multicast resources. It is important to integrate IP Multicast functionality into the architecture from the beginning, and to provide simple solutions for those problems that will not defeat the already gained advantages. 1.1. Management of Differentiated Services At least for Per-Domain Behaviors and services based on the EF PHB, admission control and resource reservation are required [14, 15]. Installation and updating of traffic profiles in boundary nodes is necessary. Most network administrators cannot accomplish this task manually, even for long term service level agreements (SLAs). Furthermore, offering services on demand requires some kind of signaling and automatic admission control procedures. Bless & Wehrle Informational
