Key distribution technique for IPTV services with support for admission control and user defined groups

Tese de doutoramento. Engenharia Electrotécnica e de Computadores. Faculdade de Engenharia. Universidade do Porto. 200

Robustness to Inflated Subscription in Multicast Congestion Control

Group subscription is a useful mechanism for multicast congestion control: RLM, RLC, FLID-DL, and WEBRC form a promising line of multi-group protocols where receivers provide no feedback to the sender but control congestion via group membership regulation. Unfortunately, the group subscription mechanism also o#ers receivers an opportunity to elicit self-beneficial bandwidth allocations. In particular, a misbehaving receiver can ignore guidelines for group subscription and choose an unfairly high subscription level in a multi-group multicast session. This poses a serious threat to fairness of bandwidth allocation. In this paper, we present the first solution for the problem of inflated subscription. Our design guards access to multicast groups with dynamic keys and consists of two independent components: DELTA (Distribution of ELigibility To Access) -- a novel method for in-band distribution of group keys to receivers that are eligible to access the groups according to the congestion control protocol, and SIGMA (Secure Internet Group Management Architecture) -- a generic architecture for key-based group access at edge routers

PIM FLOODING MECHANISM AND SOURCE DISCOVERY (PFM-SD) EXTENSION TO AVOID FLOOD BETWEEN MULTI HOME PEER

Techniques are provided to support an extension to PFM-SD that avoids multicast traffic flooding across multi-home provide edge nodes, and maintains a faster convergence capability provided by multi-homing. These techniques allow a last hop router to create two trees, and provides a framework to ensure that Ethernet Segment failure has minimum traffic close for a receiver. In addition, these techniques involve a mechanism to avoid traffic flood over a core network between peers

Design and Validation of Receiver Access Control in the Automatic Multicast Tunneling Environment

Standard IP multicast offers scalable point-to-multipoint delivery, but no control over who may send and who may receive the data stream. Participant Access Control has been developed by Islam and Atwood, but only for multicast-enabled network regions. Automatic Multicast Tunneling has been developed by the Internet Engineering Task Force. It extends the range of multicast data distribution to unicast-only network regions, but provides no Participant Access Control. We have designed the additional features that AMT must have, so that AMT has the necessary Participant Access Control at the receiver's end in the AMT environment. In addition, we have validated our design model using the AVISPA formal modeling tool, which confirms that the proposed design is secure

IMS signalling for multiparty services based on network level multicast

3rd EURO-NGI Conference on Next Generation Internet Networks. Norwegian University of Science and Technology, Trondheim, Norway, 21-23 may 2007.The standardization process of the UMTS technology has led to the development of the IP Multimedia Subsystem (IMS). IMS provides a framework that supports the negotiation of the next generation multimedia services with QoS requirements that are envisioned for 3G networks. But even though many of these services involve the participation of multiple users in a multiparty arrangement, the delivery technology at network level is still unicast based. This approach is not optimum, in terms of transmission efficiency. In this paper, a new approach is presented proposing to use a network level multicast delivery technology for the multiparty services that are signalled through IMS. The main advantages and drawbacks related with this new approach are analyzed in the article. Finally, as a starting point in the development of the presented solution, a new SIP signalling dialogue is proposed allowing the negotiation of a generic multiparty service, and supporting at the same time the configuration of the corresponding network level multicast delivery service with QoS requirements that will be used in the user plane.Publicad

Practical Rate-Adaptive Multicast Schemes for Multimedia over IEEE 802.11 WLANs

The current IEEE 802.11 standard does not address the basic requirements of multicast communication. More specifically, multicast packets are sent in an open-loop fashion as broadcast packets i.e. without any acknowledgements. This basic multicast transmission mechanism prevents the implementation of congestion control, transmission reliability and physical data rate adaptation algorithms. In this paper, we propose new mechanisms based on the leader-based approach to enhance the legacy multicast transmission scheme in WLANs. We focus on practical solutions that can be deployed in current and future WiFi devices and are compatible with legacy 802.11 devices. We propose two mechanisms to adapt the PHY data rate of multicast flows: the simplest leader-based mechanism (LB-ARF) and the Robust-Rate Adaptive Mechanism (RRAM) . Our simulations show that for static environments, LB-ARF and RRAM can achieve high multicast throughput and fairness between the set of multicast receivers. LB-ARF is sufficient to outperform the legacy multicast mechanism when the stations are fixed. RRAM improves the reliability of the multicast transmission and obtains high throughput independently of the number of receivers and the maximal speed of stations

Design and Validation of a Secured Tunnel in the Automatic Multicast Tunneling (AMT) Environment

IP multicasting is a communication mechanism in which data are communicated from a server to a set of clients who are interested in receiving those data. Any client can dynamically enter or leave the communication. The main problem of this system is that every client that is interested in receiving the multicast data has to be in a multicast enabled network. The Network Working Group at the Internet Engineering Task Force (IETF) has come up with a solution to this problem. They have developed a protocol named Automatic Multicast Tunneling (AMT). This protocol offers a mechanism to enable the unicast-only clients to join and receive multicast data from a multicast enabled region through an AMT tunnel, which is formed between the two intermediate participants named Gateway and Relay. However, AMT does not provide any Participant Access Control (PAC). Malla has designed an architecture for adding PAC at the receiver’s end in the AMT environment. His work is based on the assumption that the AMT tunnel is secure and the tunnel can recognize and pass the additional message types that his design requires. We have designed the solution to secure the AMT tunnel. We also defined the additional message types. Lastly, we validated our work using the Automated Validation of Internet Security Protocols and Applications (AVISPA) tool to ensure that our design is secure

Distributed Core Multicast (DCM): a multicast routing protocol for many groups with few receivers

We present a multicast routing protocol called Distributed Core Multicast (DCM). It is intended for use within a large single Internet domain network with a very large number of multicast groups with a small number of receivers. Such a case occurs, for example, when multicast addresses are allocated to mobile hosts, as a mechanism to manage Internet host mobility or in large distributed simulations. For such cases, existing dense or sparse mode multicast routing algorithms do not scale well with the number of multicast groups. DCM is based on an extension of the centre-based tree approach. It uses several core routers, called Distributed Core Routers (DCRs) and a special control protocol among them. DCM aims: (1) avoiding multicast group state information in backbone routers, (2) avoiding triangular routing across expensive backbone links, (3) scaling well with the number of multicast groups. We evaluate the performance of DCM and compare it to an existing sparse mode routing protocol when there is a large number of small multicast groups. We also analyse the behaviour of DCM when the number of receivers per group is not a small number