VIDEO STREAMING

Version: 2.1
Status: Proposed: 12/12/01
Contact: Ronald Olton

The purpose of this model is to provide the colleges of the Virginia Community College System with the information they need to consider when implementing video streaming services.

This model covers video streaming concepts and the components used to deliver various types of video streaming services.

This document will be updated to adapt to changes in technology, as they occur.

This model is applicable to all colleges and campuses of the VCCS.

Video streaming services allow customers with suitably equipped desktop computers to access live and pre-recorded video content. The video content may be delivered in one of three ways:

1. Live Video - A site equipped with a video production facility can generate live video content at a predetermined time. Though this is refered to as "broadcast" video, the video is actually transmitted using the IP multicast protocol.
2. Scheduled Video - Pre-recorded video content is sent from a server at a predetermined time. Though this is also refered to as "broadcast" video, the video is actually transmitted using the IP multicast protocol.
3. Video-On-Demand - Authorized customers can access pre-recorded video content from a server whenever they wish to view it.

Video Streaming Network Strategy:

The strategy adopted to ensure interoperability among the colleges is to base VCCS video streaming services on International Telecommunication Union (ITU) and Internet IP Standards.

The difficulty is that although the International Telecommunication Union has received proposals for video streaming standards, none have been approved. When a standard is approved, VCCS will adopt it.

Most video streaming applications use IP transport protocols to carry the video content from the server to the desktop client computer. This model assumes the use of IP transport protocols among all participating sites.

Video Streaming Network Considerations:

This model is not intended to specify which encoding and decoding standards colleges must use. Its intent is to identify those issues that colleges need to be aware of in making their decisions. Colleges may purchase and use the equipment that best meets their needs.

The Internet IP Multicast protocol is the preferred transport protocol for live video and scheduled video "broadcast" services. Video streaming applications that use the Internet IP broadcast protocol should be avoided because they send the video traffic to every IP subnet, even if no one is viewing it. This could flood all of the college networks with the video content.

The video-on-demand service is the first VCCS application with the potential to cause congestion on the campus DS-3 Net.Work.Virginia connection. This is because each user requires his/her own video stream. Colleges should begin managing their Net.Work.Virginia DS-3 bandwidth when implementing video-on-demand, to ensure that it does not become a problem.

Campus infrastructures must provide adequate bandwidth for the number of desktop client computers installed. All video streaming applications reviewed to date require the use of a switched campus infrastructure (see the "VCCS Campus Infrastructure Model" on the System Office Web site). This may be a switched LAN or ATM desktop environment.

Without ITU Standards, interoperability among video streaming systems cannot be guaranteed. Interoperability hinges on the client/server interface and the video compression standards used. The only way to guarantee interoperability in the current market is to adopt a system-wide solution from a single vendor.

Server sizing is a critical issue. Each server must be capable of delivering the expected number of video streams, while not overloading its campus infrastructure or DS-3 connection.

Video Streaming Networking:

There are six "components" in the VCCS Video Streaming Model. The components are arranged to create campus and intercampus video streaming environments.

Individual Customer Desktop Computers:
A desktop computer provides a video streaming platform when it includes the appropriate client software, video decoder, and access to the campus IP network.

Commonwealth Conference Center (Optional):
Colleges may support video streaming in their Commonwealth Conference Center. For more information refer to the "Commonwealth Conference Center" model on the System Office Web site.

Video Streaming Production Facility (Optional):
Colleges may implement video production facilities. The video content produced in these facilities may be transmitted as it occurs (as a "live" event), recorded for later viewing on any authorized desktop client computer, or both.

Video Streaming Server(s) (Optional):
Colleges may implement video servers as college resources. The VCC Utility or other sources may also provide shared servers. As the source of pre-recorded video content, they can provide scheduled "broadcasts" and/or video-on-demand video support. Multiple servers may be used to deliver different types of video content. The servers may transmit video content in any standardized or proprietary format (H.261, MPEG-1, MPEG-2, etc.), depending on the server design and customer needs.

Video Services Manager (Recommended):
The video services manager is an application that controls customer access to servers, video content on servers, server program scheduling, and server management operations. The owners of video servers should provide a video services manager for administrative purposes.

Video Streaming Networks:
Campus IP networks are used to transport the video streaming traffic. IP multicast support must be provided on the campus IP networks used to support video streaming. Given the current capabilities of the campus IP networks, it may also require implementation of a switched architecture. Refer to the "Campus Infrastructure Model" on the System Office Web site for more information.

Video Streaming Environments:

The video streaming environments, see Figure 1, can support all of the following at the same time:

• Multiple point-to-point video-on-demand video streams to individual desktop client computers.
• Multiple live or pre-recorded multicast video streams to any groups of VCCS desktop client computers.
• Various campus configurations, from a full implementation (see Campus 1) to just desktop computers that only receive video streaming services (see Campus n).

Video Networking Roles and Responsibilities:

Training:
Staff training on the development of video content, and on the installation, configuration, operation, and troubleshooting of the hardware and software associated with video streaming should be included in the professional development programs of the VCCS System Office and the colleges.

Security:
The owners of all VCCS video network resources and video content are responsible for protecting them in accordance with the Virginia Community College System security policy (see the "Distributed Security Model" on the System Office Web site).

The VCC Utility is responsible for providing access authorization services and processing access requests for shared video streaming components.

The colleges are responsible for providing physical security for the college and network components located on their campuses. They also provide access authorization services and process access requests for college based services.

Support:
The VCC Utility can provide system-wide monitoring of all ATM and internetworking components used for video streaming.

The VCC Utility and the colleges should maintain service contracts on all of their networking equipment, to facilitate repair and replacement of defective parts/devices.

Technical support is organized into three levels:

Level 1, the College:
College support staff provide the point of contact for their customers. They are expected to resolve routine problems related to video services.

Level 2, the VCC Utility Call Desk:
VCC Utility Call Desk staff provides the point of contact for college support staff and college customers. They are expected to resolve routine problems related to video services. VCC Utility product specialists will work with college support staff and vendors to research solutions to non-routine problems, and to obtain appropriate solutions such as product patches and new releases, etc.

Level 3, the vendors:
The vendors are responsible for maintaining their products by providing product patches, information, problem work-arounds, new releases, etc.

Video Stream Scheduling:
The owner of the video server that contains the video content will provide scheduling services and support for their servers.

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