Multimedia multi-networking: A new concept

Abstract

Recent researches in communication systems are leading to the multiplication of communication technologies. Because of this trend there is now a very wide range of different kinds of networks from copper lines for telephony to high speed fibres, as well as satellite or wireless mobile networks. It would then be very useful to be capable of using all these new communication networks all together. We call this domain related to the use by an application of several different networks “multi-networking”. But the problematic of multi-networking is two folds: (1) First, it can be really interesting to have several network access and to be able to use them in parallel. For instance, it can consist, in the case of digital and interactive tv, of using digital satellite channels for broadcasting audio and video, and using the wire Internet or anIsdn (Integrated Services Digital Network) network to send specific data to dedicated users. This is what we call “parallel multi-networking”. (2) The second folder of this problematic deals with guaranteeing Quality of Service (QoS) while connections cross several networks or domains, especially when there are firewalls orNat (Network Address Translation) servers in between that break the end to end IP model. In addition, the introduction of wireless or satellite links that have high delays and loss ratio inside the Internet can lead to important QoS degradation as wire Internet protocols are not efficient on wireless and satellite links. This aspect of the problematic is called “serial multi-networking”. This second aspect has been much more addressed in a recent past than the first one. It leads to some specific solutions, most of the time application oriented, as caching for web application for instance. To cope with other problems, as the introduction of satellite links in the Internet, proxies system have been designed to handle data flows before entering the satellite link. Proxies are, there, in charge of performing some spoofing operations. But in any case, even if there are some application specific solutions, or some network dedicated approaches, none of them is able to handle live real time traffic. Hence, this work aims to propose a new solution relying on new protocols and architecture to cope with multi-networking. The solution for parallel multi-networking is called MMPOC-MN (MultiMedia Partial Order Connection for Multi-Networking). It is based on a partially ordered and reliable communication principle that allows us to reduce the end to end delay, and to enforce synchronisation between parallel flows on separated networks. This protocol can then be tuned very precisely in order to be the optimal transmission protocol according to application requirements and network constraints. To cope also with serial multi-networking, this protocol architecture has been extended. The new general (parallel and serial) multi-networking protocol is called MNP (Multi-Network Protocol). It is based on the concept of splitting the end to end connection in several trunks, each trunk being supported by a single network domain, each domain being supported by a single technology. Then, the best suited transmission parameters are used on each trunk, and the most suited spoofing algorithms are applied on data streams depending on the application requirement model. These protocols and architecture have been developed using the opnet modeller and simulated, to evaluate the benefits of our solution. In this paper we are also focusing on how deploying such applicative protocol and architecture. The recommended solution consists in using active networking as ANTS, capable to download and run portable code on network components.