WO2006109305A1

WO2006109305A1 - Bandwith optimization in ip networks for one to many communication

Info

Publication number: WO2006109305A1
Application number: PCT/IL2006/000458
Authority: WO
Inventors: Tamir Berler
Original assignee: Ipoint Media
Priority date: 2005-04-13
Filing date: 2006-04-11
Publication date: 2006-10-19

Abstract

A system for providing audio and video communications over IP (internet protocol) networks employing of a plurality of LANs. The sending end - point is associated with a LAN with which it forms a unicast connection, the sending LAN then forms a multiplicity of unicast connections with a first tier of LANS. To the LANs of this first tier or to LANs of a second or third tier, etc. are connected receiving end - points connected each to a respective LAN. In each receiving LAN a multiple end - point connecting server distributes the datagrams among the receiving end - points.

Description

BANDWIDTH OPTIMIZATION IN IP NETWORKS FOR ONE TO MANY COMMUNICATION

FIELD OF THE INVENTION

The present invention is in the field of video, audio and data communications in IP networks. More specifically, the invention concerns distribution of video and audio between different LANs through global networks.

BACKGROUND OF THE INVENTION

Unicast communications in IP networks provide a route for sending datagrams from one end point to another end point. Common unicast applications are HTTP and FTP. Multicast communications provide routes for datagrams to be sent from at least one end-point to a predesignated group of end points. In broadcast IP communications an end-point sends the same datagrams to all connected end-points. Unicast, however, is the most common of IP communications and the only one of the three described that employs the TCP transport protocol. Broadcast and multicast do not support TCP protocol, but the multicast application is supported by the H.323 teleconferencing protocol.

Unicast is the common method of global network connection, however, the employment of audio and video is highly demanding with respect to bandwidth. To better explain the problem of bandwidth demand reference first is made to Fig. 1A. Sending end-point 20 sends a set of identical datagrams represented each by arrow 22 to global network 24. End-points 30, 32, 34 36 and 38 are all connected to global network 24. In the context of the present invention, in order to send identical datagrams to each of the end-points 30, 32, 34 36 and 38, end-point 20 has to form a one-to-one connection with all the receiving end points. The bandwidth constraints on network 24 are therefore correlated with the number of receiving end points. In the schematic network of Fig. 1B a multicast connection is used, in which end-point 20 sends a datagram represented by arrow 23 using a multicast connection, described next. End-point 20 sends a datagram to network 24. End points 30, 32, 34, 36 and 38 connect to same network 24 receiving subsequently the same datagram distributed by the network. This requires that the receiving end-points are preregistered to this application. The successful implementation of multicast connections is dependent upon firewall and router definitions. Broadcast connection is described with reference to Fig. 1C. End-point 20 connects to network 24 employing a broadcast connection. The network multiplies datagram 23 received from end-point 20 and subsequently, a copy of the datagram can be sent to any connecting end-point such as end point 30, 32, 34, 36, 38 and N.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1A is a schematic description of the prior art of one- to-many videoconferencing connections over a network employing a unicast application; Fig. 1B is a schematic description of the prior art one-to-many videoconferencing connections over a network employing a multicast connection application;

Fig. 1C is a schematic description of the prior art one- to-many videoconferencing connections over a network employing a broadcast connection application;

Fig. 2 is a schematic description of a networking layout in which the present invention is implemented;

Fig. 3 is a schematic description of a networking layout emphasizing a cascade of LANs interconnected in the method of the invention; Fig. 4 is a schematic description of the connection between LANs in which the present invention is implemented, showing firewalls and WANs.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

The system of the present invention is deployed in a framework of LANs (local area networks) interconnected by WANs (wide area networks). To describe the features of a network of the present invention, reference is made first to Fig. 2. In LAN 60 an end-point 62 forms a unicast connection with server 64 of LAN 66. The connection between LAN 60 and LAN 66 is WAN connection, using WAN 70. Server 64 forms a connection with a plurality of end-points connected to a plurality of LANs as described next. LANS 72, 74 and 76 are each connected to a plurality of end points and a specific end point hereinafter referred to as multiple end-point connecting server (MEC). Thus, LAN 72 is connected to end-points 80, 82 and MEC 84. LAN 74 is connected to end- points 86, 88 and 90 as well as MEC 92. LAN 76 are connected end-points 96, 98 as well as MEC 100. In this drawing each single headed arrow represents one datagram transmitted, and the double-headed arrows represent each a single datagram multiplied and sent via multiple routes. The WANs in the drawing, namely WANs 70, 102, 104 and 106 are designated by separate numbers but they may all be a single WAN, or any other combinations of WANs.

The configuration of the invention allows for a considerably reduced dependence on the WAN as to available bandwidth. Since the user usually has little control over the bandwidth available over a WAN connection, the number of targeted end-points may be limiting in that the actual ability form a IP connection, and especially in the case of video and audio communications, the quality may be impaired by limiting the information transmitted per unit time, to level below the acceptable minimum. Therefore the configuration of the invention is specifically applicable to video and audio applications. More specifically, video and audio conferencing applications standards are SIP, H.323, to which the present application is specifically applicable.

Functionally, LAN 66 is a sending LAN whereas LANS 72, 74 and 76 are receiving LANs in the context of the invention. Sending server 64 of LAN 66 after having received a datagram from sending end-point 62 forms unicast connections with each of the receiving LANs, namely LANs 72, 74 and 76. However, since a plurality of receiving end-points are connected potentially to each receiving LAN, the process uses a MEC in each receiving LAN for distributing the received datagram to the respective receiving end-points employing a unicast or multicast connection.

A generalized network of LANs configured in cascading fashion implementing the invention, utilizes a sending end-point with video and audio capturing facilities and appropriate codecs for facilitating the transmission thereof, and is activated by, for example, a lecturer. In another, simpler configuration in which the invention is manifested described in Fig. 3, file 62 is sent by sending server 64 connected directly to LAN 66 by using unicast connections to a first tier of LANs 70. Each of these LANs is capable of connecting to second tier of LANs 72 via a unicast connection. Within each of the

LANs of both the first and the second tier, a MEC 74 may be connected as explained above for distributing the datagrams within the LAN. Benefits of the use of the invention

The configuration of network implementing the present invention reduces the dependence on availability of WAN bandwidth. The number of receiving end-points does not directly correlate with the bandwidth required for communicating audio and video from a sending end-point to a multiplicity of receiving end-points. The method of the invention requires the employment of one sending server to a multiplicity of receiving servers (MECs). The employment of an end-point serving as a receiving server in each receiving LAN can be used to allocate a substantial computing power of the application to the receiving server. For example, the videoconferencing application (SIP, H.323) freeing user end-points resources to other applications, or alternatively requiring end-points with less computing power as compared to the MEC.

In a co-pending IL 161050 patent application, sharing a common inventor with the present application, a method of sending video and audio traversing firewalls, NAT/PAT and HTTP proxies is disclosed. The disclosed method facilitates the formation of connections between a plurality of end-points over a global network in which multimedia tasks are realized. The essence of the invention is a tunneling process of the multimedia applications in HTTP connections. Applying the method provided by the present invention over a system employing HTTP tunneling is described schematically in Fig 4 to which reference is now made. In Fig.4 networks and exemplary security applications are shown. Thus, LAN 120 employs firewall 122, and a connection is formed by traversing firewall 124 of a WAN 126. LAN 128 connects to WAN 126, through its own firewall 130, and traversing the WAN's firewall 132. An additional LAN, designated 140, connects to LAN 128 through firewall 142, firewall 144 WAN 146, firewall 148 and firewall 150, in that order.

A sending end-point 170 utilizes the HTTP connections to transfer datagrams to receiving end points 172 and 174. In accordance with the present invention, end-point 170 forms only one unicast connection to send datagrams conveying video and or audio information to end-points 172 and 174, trough all the network components described.

Claims

1. A system for providing audio and video communications over IP (internet protocol) networks, comprising:

• one sending end-point forming a unicast connection;

• a sending server associated with a sending LAN, and wherein said server receiving datagrams from at least said sending end-point; • a receiving LAN with which one multiple end-point connecting server is associated, and

• at least two receiving end-points forming a unicast connection with said receiving LAN.

2. A system for providing audio and video communications over IP networks as in claim 1 and wherein firewalls, NAT/PAT and HTTP proxies are traversed using HTTP tunnelling.

3. A system for providing audio and video communications over IP networks as in claim 1 and wherein said multiple end-points connecting server of said receiving LAN forms multicast connections with other end points of said LAN.

4. A method for providing audio and video communications over IP (internet protocol) networks, comprising:

• at least one sending end-point forming a unicast connection using a sending server associated with a first sending LAN, and wherein said server receives datagrams from said at least one sending end-point;

• receiving datagrams by a second receiving LAN with which one multiple end-point connecting server is associated, and • receiving datagrams by at least two receiving end- points forming a unicast connection with said second receiving LAN.