This paper argues that tree based protocols can have packet delivery ratios comparable to mesh based protocols if the tree construction algorithm can fix and detect broken links quickly, and at the same time have a much lower data packet overhead due to the absence of redundancy. We present such

In multicast communication, it is often required that feedback is received from a potentially very large group of responders while at the same time a feedback implosion needs to be pre- vented. To this end, a number of feedback control mechanisms have been proposed, which rely either on tree-based feedback aggregation or timer-based feedback suppression. Usually, these mechanisms assume that it is not necessary to discriminate be- tween feedback from different receivers. However, for many applications this is not the case and feedback from receivers with certain response values is preferred (e.g., highest loss or largest delay).

Abstract—We present CPM, a unified approach that exploits server multicast, assisted by peer downloads, to provide efficient video-on-demand (VoD) in a service provider environment. We describe our architecture and show how CPM is designed to dynamically adapt to a wide range of situations including highly different peer-upload bandwidths, content popularity, user request arrival patterns (including flash-crowds), video library size, and subscriber population. We demonstrate the effectiveness of CPM using simulations (based on the an actual implementation codebase) across the range of situations described above and show that CPM does significantly better than traditional unicast, different forms of multicast, as well as peer-to-peer schemes. Along with synthetic parameters, we augment our experiments using data from a deployed VoD service to evaluate the performance of CPM. I.

This paper introduces a new probabilistic specification of reliable broadcast communication primitives, called #-Reliable Broadcast. This specification captures in a precise way the reliability of practical broadcast algorithms that, on the one hand, were devised with some form of reliability in mind but, on the other hand, are not considered reliable according to "traditional" reliability specifications.

Abstract. Existing multicast traffic engineering (TE) solutions tend to use explicit routing through MPLS tunnels. In this paper we shift away from this overlay approach and address the bandwidth constrained IP multicast TE directly based on link state IGP routing protocols. The objective is that, through plain PIM-SM shortest path routing with optimized Multi-topology IS-IS (M-ISIS) link weights, the resulting multicast trees are geared towards minimal consumption of bandwidth resources. We apply Genetic Algorithms (GA) to the calculation of optimized M-ISIS link weights that specifically cater for engineered PIM-SM routing with bandwidth guarantees. Our evaluation results show that GA-based multicast traffic engineering consumes significantly less bandwidth resources in comparison with conventional IP approaches, while it also exhibits higher capability of eliminating/alleviating link congestion. The key contribution is a methodology for engineering multicast flows in a pure IP environment, without MPLS explicit routing that potentially suffers from scalability problems in terms of LSP maintenance. 1

. The Source Specific Multicast (SSM) service model and protocol architecture have recently been proposed as an alternative to the currently deployed Any Source Multicast (ASM) service. SSM attempts to solve many of the deployment problems of ASM including protocol complexity, inter-domain scalability, and security weaknesses. However, the SSM protocol architecture is not radically different from that of ASM. This has created opportunities for integrating it into the currently deployed ASM infrastructure. In this paper, we first describe the ASM and SSM service models and associated protocol architectures, highlighting the relative merits and demerits of each. We then examine the network infrastructure needed to support both of them. Our conclusion is that integration is relatively straightforward in most cases; however there is one case---supporting ASM service over an SSM-only protocol architecture---for which it is difficult to design elegant solutions for an integrated SSM/ASM infrastructure. 1

This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026 [RFC 2026]. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at

Originally, paging has been used in cellular networks to alert a mobile station of an incoming call within a paging area comprised of several cells. Today's most popular usage of paging is the exchange of short messages. With growing importance of all-IP mobile networks it is expected that an IP paging service will prevail. This report studies the usage of paging in IP-based networks to search mobile hosts in order to find their current point-of attachment. It allows the mobile host to update the network less frequently and to provide the network with only approximate location information. The approach is contrary to the case where a mobile host registers each time a handover occurs and the network tracks the exact location of the mobile host. Clearly, there is a tradeoff between tracking and searching.

Abstract IP multicast deployment recently progresses, but group services often remain restricted to limited domains and fail to comply with route-optimizing mobility management of the next generation Internet. Source Specific Multicast (SSM) facilitates transparent inter-domain routing and is expected to globally disseminate to many users and services. However, mobility support for Source Specific Multicast is still known to be a major open problem. In this paper, we propose the Enhanced Tree Morphing (ETM) protocol for extending SSM routing to mobile multicast sources. The scheme dynamically adapts SSM forwarding states to sender mobility, and transforms (morphs) source specific distribution trees into new, optimal trees rooted at a relocated source. ETM is simple, robust and secure, while it admits superior performance in packet forwarding at a low signaling overhead. Extensive evaluations based on a full protocol implementation, and simulations based on real-world topology data are performed, granting full insight into the properties of packet loss and delay stretch, protocol convergence times and router state evolution during single and rapidly repeated handovers. In a constant bit rate scenario, an ETM source handover typically leads to a slightly increasing de-

draft-irtf-routing-history-06.txt By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at