Fast learning through ATM - Stanford University's Asynchronous Distance Education Project - Company Operations

Communications News, April, 1997

One university's project to extend degree education to a wider population required fast wire and switches.

Stanford University is Swell-known as a pioneer in delivering televised degree education to the workplace and has granted more than 3,000 degrees through its distance learning programs. But there was still a large group of students the traditional televised classroom model could not serve--those who were not able to attend classes at a particular time.

Using ATM network technology, Stanford University's Center For Telecommunications developed the Asynchronous Distance Education Project (ADEPT), an innovative program that offers "virtual" classes from remote locations, enabling students to gain access to curriculum materials from their desktop computers at any time of the day or night. ADEPT achieves the university's goals of providing higher quality educational content, reducing costs, and most importantly, increasing class access to a broader set of students.

ADEPT was designed to take distance learning to a new level. Its main purpose: to provide access to advanced graduate courses using state-of-the-art computer and networking technologies. The classes being offered through the ADEPT program are for computer scientists, engineers, and technology managers working toward technical degrees at the Stanford School of Engineering. The working professionals using the ADEPT network can access the class materials from their offices, at home, and even while traveling at any time of the day.

The network required a high bandwidth technology capable of delivering integrated video, audio and data. The center's executive director ultimately decided on ATM switching to construct a high-speed distribution network.

"Our unique Education On Demand application required an ATM network to deliver dedicated circuits, provide high bandwidth and allow the network to deliver real-time playback," says Dale Harris, executive director at Stanford's Center For Telecommunications. "The quality of service capabilities and advanced cell-switching features inherent in ATM accommodate our needs perfectly."

With this in mind, Dale Harris explains the university's approach to meeting these goals: "We made a concerted effort to provide a flexible system that allowed students to participate regardless of their type of computer system and their location. They could use high-speed ATM connections if available, or use a direct Internet connection."

As the students in the program come from a variety of environments, from companies of all sizes, it was imperative that access be available from all platforms--PCs, Macs and Unix workstations. The main thrust was to build a high-impact, high-quality distance education program.

After capturing the video, audio, and class notes, the information is digitized and compressed into a variety of formats, including MPEG and Quicktime for audio and video. Data files are saved in PostScript and PDF formats. This information is then transferred onto highspeed servers that feed into the distribution network.

The digitization was originally done with PCs tied together in an Ethernet LAN to the distribution servers. Given that audiovisual file sizes ranged from 60 MB to 600 MB, and the realized Ethernet data rate was about 150 kb/s, the file transfers to the servers were extremely slow.

To solve this problem, the center decided to utilize ATM technology by installing ATM25 network adapter cards from Adaptec in the digitizing PCs and running the network through Whitetree's WS3000 workgroup switch. Servers were connected to the switch at speeds of ATM155, ATM25 and 10 Mb/s Ethernet. With an ATM link, the center has been able to move an hour's worth of A-V material in less than a minute.

On campus, students can access the servers through a campus-wide 10Base-T Ethernet network; off-campus students access the information via the Internet through a company LAN connection, or connect via ATM through a metropolitan area network.

The ATM metropolitan area networks that have served as the test beds for the ADEPT project include the Stanford Cardinal Testbed, BAGNet (Bay Area Gigabit Network) and the Sprint Silicon Valley Test Track (SVTT).

A variety of network equipment is being used at Stanford for the project. The video servers include a Sun SparcStation 10, Silicon Graphics Indigo and The Virata Store by ATM Limited. ATM switches from a variety of vendors, including Whitetree's WS3000 switches, provide a workgroup switching function.

Whitetree's switches have provided a key link for the ADEPT ATM network. The architecture of the switch allows its 12 fixed ports to be configured as either switched Ethernet or ATM25 on a port by port basis.

In addition, ATM155 Network Option modules plug-in to two slots in the back of the switch to provide connectivity to a Bay Networks' LattisCell backbone switch.

For remote students with ATM adapter cards, the high-speed access through the Whitetree WS3000 and other ATM switches allows for efficient delivery of multimedia class curriculum.