IP Video Deep Dive

The IP Video Revolution
Videoconferencing Basics
Why Business Deploy IP Video?
ISDN vs. IP
Other Enterprise Issues
Elements of a Leading Solution

The IP Video Revolution

Today, ISDN is slowly being replaced by IP, which offers greater flexibility, ease of use and lower cost. Global Crossing has moved to the forefront of the IP video revolution - leveraging our best-in-class MPLS-based converged IP network to provide both managed IP videoconferencing services and high-quality IP video transport over our IP VPN infrastructure. We've also pioneered ways of using our worldwide IP network to carry ISDN video traffic, in addition to conferencing IP and ISDN endpoint devices together seamlessly. These innovations significantly increase convenience and lower total cost of videoconferencing for our customers, extending the useful lifespan of ISDN video equipment and letting customers migrate to IP at their own pace.

The market shift has been made possible because videoconferencing has evolved rapidly over the past decade, driven by ever-more-powerful low-cost computing technology and increasingly ubiquitous data networking. Endpoint device costs have dropped radically, as the market's emphasis has shifted from big-ticket, modular 'boardroom' systems to smaller, simpler, mobile, and more affordable video products.

Likewise, the nature of network transport services used to connect videoconferencing endpoints has changed. It has gone from using private line services to connect two videoconferencing units in fixed locations to more flexible multi-line dialup service, allowing one or more dialup digital telephone lines to work in parallel providing the bandwidth required for a video call.

Conference 'bridges' have also evolved. Conference bridges accept inbound transmissions from two or more videoconferencing endpoints and combine these in a coordinated display under moderator or participant control. These now enable multi-party and broadcast videoconferencing with numerous endpoints, and can improve the videoconferencing experience by simplifying connection and adding feature-functionality.

Videoconferencing Basics

Today's videoconferencing systems run the gamut - from highly modularized 'boardroom' systems incorporating multiple video cameras and other data transmission devices, to 'desktop' videoconferencing systems that couple a camera and microphone to a laptop.

All videoconferencing endpoints are data devices that collect input from microphones, video camera and other data sources, and then encode the captured audio and video in a frame (ISDN) or packet (IP) format for transmission. Video transmission (like TV) is a form of still-picture animation. The camera captures a sequence of frames at regular intervals and transmits them. The receiving system displays them at the same rate they were recorded, exploiting persistence of vision to create the impression of motion. Today's video systems support frame-rates up to 30 frames per second (fps), equivalent to TV broadcast.

Videoconferencing codecs (Coder/Decoders) use a range of techniques to reduce bandwidth requirements. One common method involves transmitting an initial key frame, then comparing with subsequent frames and transmitting only those sections of the image that have changed. The tradeoff is with delay - you can reduce data volume significantly through image-analysis and compression; but by doing so, you consume machine-cycles at each end, for compression and decompression, increasing latency.

If satisfying real time video is the goal, latency is the enemy - increasing the time lag between answer and response and putting video out of synch with audio. Videoconferencing codecs prioritize the transmission of audio (which requires far less bandwidth than video) in order to maintain intelligible communications, even when network conditions (which may vary in certain circumstances) preclude clear, full-rate video transmission. But when video is delayed, loss of synch (e.g., between the sound of speech and visible lip-movements and facial expressions) becomes highly noticeable and distracting.

Network capacity and performance therefore becomes crucial -- for best-quality videoconferencing, you want a network connection with lots of bandwidth, very low overall transmission latency, and minimal "jitter" (delay variation between succeeding bits, bytes, frames or packets). This permits endpoint devices to capture high-resolution frames, use higher frame-rates, employ minimum compression, keep receive-buffer sizes small, and maintain good synch between audio and video. If network performance is impaired more than a minimum amount, video and audio quality both suffer markedly. When videoconferencing endpoints are connected via switched, TDM-based ISDN service, such severe performance impairments are rare and transitory - generally caused by network equipment failure. On unmanaged IP networks, however, performance impairments are more common. This is where Global Crossing's network is a strong selling point. We offer enhanced SLAs to leverage the exceptional performance of our IP network, which has been operating at 99.999 percent availability, and under 5 ms of jitter for the year to date.

Why Business Deploy IP Video?

Videoconferencing is growing fast. As with other conferencing services, the increased interest reflects many trends, including:

• The need to deliver presentations with a "human dimension," while saving the time, hassle and expense of business travel.
• The need to coordinate globally dispersed workgroups, while building rapport and interacting insightfully across time zones and language barriers.
• The need to work remotely, aggregating expertise and leveraging it across distance (e.g., telemedicine, legal videoconferencing).
• The need to observe remotely: for authentication, security, management and control.
• The need to transport video and other media content in real-time for broadcast media production and similar applications.

Get an estimate of just how much iVideoconferencing can save you over travel costs.

ISDN vs. IP

For this reason, over the past three or four years, videoconferencing over IP networks was a hit-or-miss affair, supported mostly by products for the hobbyist market and for special applications like remote viewing or security, where real time interaction was of secondary importance. Makers of business-class videoconferencing gear were slow to support IP, preferring the greater reliability and dedicated bandwidth afforded by multi-ISDN connections.

As the performance of IP premise networks and WAN facilities have improved, Internet use has flourished, and broadband service has become more affordable. This has led to ISDN video users looking for opportunities to switch to IP - converging videoconferencing services on their IP LANs and wide-area networks in the same way as some businesses are now using IP telephony, or VoIP. In many cases, however, they are held back by uncertainty over issues of network performance, particularly over WAN links; and by the desire to extend the useful life of costly, ISDN-based videoconferencing gear.

In other cases, enterprises have elected to move forward towards IP-based videoconferencing, usually in a gradual migration. Here, however, they immediately encounter problems. IP and ISDN videoconferencing equipment work over different media and employ related but incompatible protocols for signaling and call control. So the new equipment can't communicate with the legacy equipment.

ISDN-based video endpoints are engineered to make direct, point-to-point connections over dialup network services. IP-based video equipment, however, shares access to the enterprise data network, and may need to communicate across firewall and Network-Address Translation (NAT) barriers with devices elsewhere on the enterprise WAN. To facilitate communications, intermediate devices - called H.323 gatekeepers - are required; and these are not conveniently scaleable across multiple domains. Extending gatekeeper services for videoconferencing across a multi-location enterprise may require purchase, configuration and management of numerous premise-based gatekeeper devices, in addition to IP endpoint equipment.

WAN performance offers another roadblock to IP video deployment across the global enterprise. Legacy WANs are typically provisioned with far less bandwidth than premise network backbone, and while special equipment can be added to prioritize video and other real time traffic across WAN links, this is costly and complex.

Other Enterprise Issues

Businesses thus face many roadblocks of cost, complexity, scale, and compatibility in deploying videoconferencing, whether the decision is made to exploit ISDN, IP or migrate from one form of transport to the other. But these platforms and cost issues are complemented by additional strategic problems.

Videoconferencing offers many challenges requiring a degree of technical facility, familiarity with equipment and relevant commands, access to ISDN phone numbers, IP addresses or H.323 device id names, and other information. Scheduling and notification of participants, distribution of materials, conference moderation and post-conference follow-up add additional complexity. What many videoconferencing users require is more of a complete solution - where a partner/vendor organization essentially handles the complexity of device configuration, service provisioning, pre-service testing, and the logistics of conference management, insuring a timely, effective video meeting.

Elements of a Leading Solution

Global Crossing's iVideoconferencing service, which this year won a Frost and Sullivan award for "Best New Videoconferencing Service," is engineered to help relieve cost-pressures and IP compatibility issues for H.320/ISDN videoconferencing users.

The iVideoconferencing service lets ISDN users bypass the PSTN in reaching international locations; instead, transmitting the ISDN data and call-progress signaling across our IP/MPLS backbone network in packet form. To make a connection, Global Crossing conference managers originate one or more ISDN calls from a nearby Global Crossing Video Hosting Zone to one ISDN endpoint. A multi-protocol video bridge then converts the signal, transits our network across a pre-provisioned IP VPN connection to a hosting zone near the other endpoint, and is re-originated as ISDN for connection to the destination device.

From the user's point of view, iVideoconferencing is a 'technologically transparent' managed service. Video data is transmitted across our network at highest priority, producing sufficiently high performance to maintain the end-to-end connection without "spoofing" (using intermediary equipment to feign expected confirmation). Indeed, the performance of iVideoconferencing-mediated ISDN video exceeds that of end-to-end ISDN, reducing the instance of video issues by more than 50%, on average.

Adding flexibility, the iVideoconferencing service can also be used to establish a point-to-point connection between an H.320 ISDN videoconferencing endpoint and an H.323 IP video endpoint connected to our network. In this case, an ISDN call to the hosting zone is completed on the IP side.

To simplify and increase the utility of the basic service offering, Global Crossing offers a full suite of reservation, management and technical services before, during, and after the call, providing multinational corporations with a consistent end-user experience, worldwide. Multi-party conferences via iVideoconferencing are launched by Global Crossing technicians, who insure connectivity, quality, and timeliness of service. Point to point meetings can be connected automatically, as scheduled by GC's ReadyView Instant Meeting web-based reservations support, which can be integrated with Outlook on customer desktop PCs, via our 'iCalendar' feature. And operator assistance and Help Desk services are available at any time.

By using iVideoconferencing instead of direct-dial ISDN, customers can save between 40% and 70% on international transport costs. Added to this dramatic cost savings is the increased simplicity, service availability, improved performance and reduced technical support requirements, partly afforded by the service itself, and partly by Global Crossing's management, technical and customer support services. And of course, iVideoconferencing also provides an upgrade path towards IP convergence without compelling replacement of expensive ISDN video equipment.

Global Crossing's flagship IP Video service solves significant problems with H.323 IP video deployment, conference quality and performance, and application management. It employs our IP VPN service to link customer locations with one another, and with video hosting zones at various locations.

To engage GC's IP Video services, customers buy IP VPN along with the video service offering -- their VPN is spun up at the same time as our gateways and other applications are provisioned with their video endpoint device information. Bandwidth across the VPN and necessary access connections is metered according to anticipated usage -- both by videoconferencing and other applications. A single Global Crossing project manager, who provides a single point of contact and insures a smooth transition to GC as the new provider, directs the upgrade to IP VPN and IP video.

The Global Crossing IP VPN operates as a single global IP WAN, using one connection per customer location to connect all facilities across an "any-to-any" logical network mesh, and optionally mapping and converting IP addresses to align local IP addressing schemes. The IP VPN connecting customer locations and hosting zones receives priority class of service for best possible performance. Because it runs across Global Crossing's private network, customer premise networks and traffic are never exposed to the Internet, with its attendant security and performance issues.

Like iVideoconferencing, Global Crossing's IP Video service is fully managed. Endpoint devices are certified for performance upon installation, and performance is re-verified remotely prior to conferences. The full suite of attendant-mediated and automated reservation, conference setup, moderation, trouble management, post-conference reporting, conference recording, satellite downlink, media streaming, and T.120 data conferencing services is offered -- services are provided by technicians at the video hosting zones; by customer support and conference management agents at our three Conference Greeting Centers; and in some cases, by select partner vendors (e.g., media streaming). Global Crossing takes care of every detail, before, during, and after the call.

The ultimate result is to let customers migrate towards IP video at any pace that suits them, to vastly simplify and improve the performance and serviceability of both ISDN and IP video endpoint equipment, and to improve the conference experience for participants. Free from unnecessary complexity and migration/compatibility issues, Global Crossing customers are free to explore the full potential of video as a strategic application.

While Global Crossing's video service offerings constitute a compelling point solution, customers seeking even more dramatic cost and operational benefits may exploit Global Crossing's IP VPN to build fully converged networks. VoIP can also neatly transition priority IP VPN channels from premise to premise; and Global Crossing's VoIP services permit cost-effective origination and termination of VoIP traffic to and from the global PSTN as well. Global Crossing's IP video offering can be a catalyst that revolutionizes the way a business works with video, voice, and data.

The bottom line is, video services form one of Global Crossing's fastest-growing and most-profitable lines of business; a place where all our key technologies come together under the banner of IP convergence. Video confirms the performance of our network and validates our overall 'one IP network for everything' strategy. And as a high-value strategic application, iVideoconferencing and IP Video are now catalyzing customers to make the switch to converged IP networking, the Global Crossing way.