The Adirondack Region posed a variety of challenges to those creating the network. Technology infrastructure was lacking and the "members" were seeking access to high bandwidth lines that would allow applications such as videoconferencing, distance learning, internet connectivity and telemedicine. The final challenge was financial-- these advanced telecommunications services had to be delivered as cost-effectively as possible.

The "hybrid cloud" model, utilized in the creation of the network, offered an innovative solution to the region's networking needs. Utilizing frame relay technology, the network provides an integrated telecommunications solution, supporting two-way interactive video for distance learning & telemedicine, LANs, WANs, data exchange, Internet access, Voice-over-IP, ISDN, T1, T3, ATM, and other technologies and allows bridging to other frame relay clouds.

Models Considered

To cost effectively meet the demand for Internet access, distance learning and telemedicine, a comprehensive network solution was required. ATM technology, while capable of delivering these services to the region, was considered too expensive. Standard unswitched IP solutions, although economical, would not satisfy the bandwidth demands of high quality video. Satellite up- and down-links were considered for distance learning, but they are cost prohibitive for two-way interactive video conferencing. Fractional T1 lines were ruled out because of cost. ISDN was considered, but its low bandwidth and unreliability were of concern and ISDN service is not universally available in this region. These solutions would also require additional infrastructure for Internet connectivity. Frame Relay was identified as the only economical, comprehensive solution.

The AAN Frame Relay Cloud

The Adirondack Area Network (AAN) utilizes a frame relay cloud. Much of "the footprint" is Bell Atlantic Inc, a telecommunications company serving the Northeastern United States. The technology involved in the AAN is the most innovative, state-of-the-art, integrated solution available at an affordable cost to the end users. Video over frame relay was not thought possible, but careful design and creative solutions designed by AAN, VTEL, formerly Compression Labs, Inc. (CLI), and RADVision, has led to one of the first public networks of this kind.

Typically members access the network through a virtual connection (PVC) the frame relay cloud. Frame relay is a flat rate service so there are no long distance charges within the cloud. Fractional bandwidths are possible and high bandwidth pipes (1.5M-45M) are available. The CIR (Committed Information Rate) is the minimum speed guaranteed when you access the cloud, but "bursts" (exceeding the CIR) are possible. Because the frame relay cloud is a shared resource, the cost is substantially less than what is found with traditional models such as ISDN. By creating logical circuits in the frame relay cloud dedicated to video applications and other circuits dedicated to data, the AAN guarantees the necessary bandwidth for high quality video. Instead of costly point-to-point connections, sites need only to connect to the nearest access point for the cloud. Sites receive Internet connectivity and high quality video connections for about the price of Internet connectivity by other means. The audio-video signal is of television/compact disc quality, even at 384K bandwidth.

TCP/IP is the protocol used in the AAN frame relay cloud. The video signals are H.323e; IP encapsulated H.320, or H.323 video protocol. Multipoint video calls are supported in this environment. In the diagram above, the Video Interface Unit (VIU), a RADVision product converts the H.320 signal to H.323, or H.323e. The gateways, also provided by RADVision, support ISDN "head-ins" into the AAN cloud. The gateway also functions as a "phone number to IP translator", that is, they serve as a video conferencing PBX. Both BRI and PRI ISDN lines are supported. The Radvision PRI gateways are an efficient way to use the entire 1.5mb/s bandwidth. These gateways allow both video and voice calls in steps of 64kb/s into and out of the frame relay cloud. The gateways act as an IMUX as well as a PBX. In the case of BRI there are two methods to use the Radvision gateways, connect an IMUX to the V.35 port of the gateway or use the BRI cards in the gateways. Some members of AAN reserve their own BRI lines at the AAN Network Operation Center (NOC), while others share several sets of ISDN lines and use the line hunt features of the gateways. Members treat the ISDN capabilities as "dialing 9 to get out" and typically do Direct Inward Dials (DID) to other members. Interestingly most AAN members do not have ISDN capabilities near their institutions. Their only method of making ISDN calls is via the AAN Cloud. These members "dial" out of their LAN through the frame relay cloud, then to the AAN NOC (where ATM is the backbone) and finally out the gateways to the ISDN cloud. To the enduser this path is seamless. In some cases the nearest ISDN POP to institutions is 150 miles away, yet they still have full ISDN capabilities.

While CLI's (now VTel) Radiance video conferencing unit was used in the initial beta test, other products have been used as well. VCon's new H.323 desktop line has been tested as a LAN/WAN solution, Tandberg, PictureTel, Intel, and Zydacron. ILINC's desktop solution using TCP/IP multicast has also proven to be successful. Cisco and RealTech have been instrumental in design efforts to protect the video bit streams from data bit streams. Routers can vary from the 2000 series to the 7000 series, depending on the site and type of connectivity. VideoServer'sVideoServer's Multipoint Conferencing Server II is presently being used as a video bridge, and front-ended with RadVision gateways it also acts as a H.323 & H.323e bridge. RadVision MCU's are being used as well. These MCU bridge H.323 calls, and are also multipliers for physical H.320 ports.

The AAN and Bell Atlantic engineers control the Bell Atlantic frame relay cloud topology. For more information regarding these AAN technical aspects contact Dr. David Bonner (bonner@aanet.org), Dr. Jackie Ford (jackie@aanet.org) or Ken Sperl (sperl@aanet.org).

Initial funding for the AAN was obtained through the New York State Advanced Telecommunications Project. The network initially linked The Sage Colleges, Albany Medical Center, Adirondack Medical Center, two Franklin-Essex-Hamilton BOCES sites (Malone & Saranac Lake), Champlain Valley Physician's Hospital Medical Center, Elizabethtown Community Hospital, the Alternative Learning Center in Troy, and two Clinton-Essex-Warren-Washington BOCES sites (Plattsburgh & Mineville). Many multimedia sites have been added since that time.