Bandwidth Overview. Rev Whitepaper

Transcription

1 Rev Whitepaper

2 About the Arel ICP Platform Arel s Integrated Conferencing Platform TM (ICP) is an advanced platform that combines the critical aspects of verbal and visual communication video and two-way audio with rich content, collaboration, discussion groups, application sharing and live interaction. The communications platform reaches and connects large numbers of people in real-time through any combination of satellite, video conferencing and internet/intranet networks. Arel s universal conferencing enterprise software solution is an integrated suite of applications for interactive voice, video and data web communication that changes the way people work by providing them with enhanced communication tools. These tools make meetings more effective and facilitate collaboration for key business processes such as corporate and marketing communications, distance learning, product development, customer relationship management, and supply chain management. Using Arel Spotlight applications, geographically dispersed users can work together in groups, attend webinars and panel discussions, participate in training courses, and have one-on-one meetings with customers or colleagues, from virtually anywhere using desktop systems, laptops, keypads or even handheld wireless devices via Internet, Intranet or PSTN connections. This document contains proprietary information of Arel Communications and Software Ltd. ( 1

3 Bandwidth Driven by the demand for hundreds of simultaneous Arel end users participating in the same session over various types of network topologies and connections, Arel places a high priority on network efficiency and performance. There are several factors that take part in Arel s bandwidth management, such as: IP multicast support Arel ICP sessions can utilize an IP multicast enabled network, for dramatic reductions in network bandwidth use during a live session. Bandwidth ranges Audio: 4-64 Kbps, Video: 25Kbps-1Mbps or higher when available, application sharing: 2-64 Kbps, Chat and messages: 2-5 Kbps. Distributed server architecture Arel s servers can be installed in a distributed environment. This architecture includes all servers including an application server, audio/video servers and web servers. The distributed servers are working in a synchronized harmony, transferring between them only one set of data or streams required by all clients and additional servers connected to the remote server. This allows for scalability, improved performance and improved bandwidth utilization. Content distribution Arel operates a content distribution mechanism (see also scalability) that pre-caches recorded and live content to distributed servers. Thus, upon the publishing of the content, or other events to be determined by the administrator, content can be distributed for remote storage close to the end users. This distribution automatically uses multicast or unicast, sends the content during off-network-peak hours and uses bandwidth limitations per remote server. When clients need the content for the session, they then approach a locally located server and get the content immediately, improving performance and not using the lower speed and more crowded long distance portions of the corporate network. This creates a dramatic savings in bandwidth requirements for bandwidth on the intranet, and enables the use of rich media content without unnecessary and unacceptable delays. This mechanism is in addition to local pre-caching to the client s hard disk and can be both implemented at the same time. Content pre-caching A mechanism exists for pre-caching of course content from the web server to the clients local disk automatically in advance. This agent is part of the Spotlight client installation. When enabled, it automatically starts using default values, with no user intervention and is highly configurable. It is possible to pre-schedule content download times for network traffic management. Unicast and multicast transmission modes are both supported. Multicast over non-multicast networks using multiple NICs While the most efficient way to locally distribute audio/video/application sharing and content to multiple participants is by using multicast (thus putting it on the network only once as compared to per participant), in many buildings it is impossible because the network segments are not connected in a multicastenabled way. This is either because old routers are used or because they are not configured to pass through multicast data. This document contains proprietary information of Arel Communications and Software Ltd. ( 2

4 An Arel server has the capability to multicast on multiple local network segments simultaneously by having multiple Network Interface Cards (NICs), each finding out the requirement of the streams by participants on the multicast-enabled segment they are on. By connecting the server to multiple network segments it is possible to reach a level of bandwidth optimization never before available so that at most one set of streams goes over any network segment, but only if required. Easy configuration per session of stream bandwidths administrators or instructors can set the speeds of the different streams they send, per stream, including audio, video (or no video at all), application sharing, content download, etc. This allows for setting the bandwidth so that it is adjusted to the audience of the session for optimal experience and at the same time to set it so that it does not jeopardize the performance of other data using the same network. Quality of Service (QoS) mechanism and dynamic change of stream bandwidth With proprietary audio and video conferencing, application sharing and messaging servers control over the actually used bandwidth of each component (video, audio, content download, application sharing and messaging) to maximize the quality of the entire session at every point in time. The Spotlight client dynamically tests the actually available bandwidth and adapts bandwidth requests accordingly, using an algorithm that sets limits to bandwidth from each of the following data flows: Web Server (content), Audio and Video Server, Application Server (messages & application sharing). Thus, it may dynamically decide, on a per participant basis, to lower content download speed in order to keep the quality of audio up, or to give up on video transmission when application sharing starts if bandwidth availability is not sufficient for both, and so forth. Silence detection A mechanism for lowering the effective bandwidth by detecting silence periods. Highly compressed application sharing Arel s application sharing engine compresses the application commands to the screen memory and sends them to the application sever for distribution, ensuring high compression rate and optimal bandwidth utilization. Additional optimization of bandwidth and performance was done in version 17. Narrowband connection support Almost full product functionality, except for video, is supported over a single network connection as low as 28.8 kbps. Depending on bandwidth availability users may also enjoy video (starting at 56.6 Kbps connection). When bandwidth does not allow for video to be seen, a still picture of the presenter or moderator is displayed in the video area. This document contains proprietary information of Arel Communications and Software Ltd. ( 3

5 Layered video Arel s layered video technology produces a video stream with representations of various resolutions and qualities. A particular quality can be obtained by decoding a particular subset of the coded data. These layers can then be transmitted in separate data streams. The server will provide the appropriate number of layers to receiving client based on o o Size of window they display of a specific source Overall bandwidth available to them QoS handling Arel s platform consist of a unique QoS mechanism which measures all transmission rates, error rates, and other broadcast characteristics across all communications types (video, audio & data) taking into consideration the network condition and its overall effect on all types of communications. Example: Large files are suddenly broadcast over the network; the mechanism will allocate a larger portion of the bandwidth to the content while it will reduce the bandwidth used by the audio and video. This document contains proprietary information of Arel Communications and Software Ltd. ( 4

6 Bandwidth consumption Arel s platform can be tuned to the performance needs of the customer. The system supports various audio and video codec s ranging from narrow-band to ultra-band. Audio codec s supported: GSM, G.711, G.722, G.722.1, G.723.1, G.729, G.729a, Speex Video codec s supported: H.263, H.264, 20Kbps to 2Mbps Minimal configuration Example of an average configuration with medium video quality and rich interaction Example of a configuration with high video quality and rich interaction Audio 8kbps 8kbps 8-64kbps Live video 30kbps kbps kbps Data (messages, chat) 4kbps 4-30kbps 4-30kbps Total (audio, video, etc.) 42Kbps kbps kbps This document contains proprietary information of Arel Communications and Software Ltd. ( 5