It may have been a bellwether event for the Internet broadcasting industry: On April 28, thousands of fans of Philadelphia's hottest rock disc jockey not only heard his radio show on the Internet, but they also saw Pierre Roberts live in action from 1 to 2 p.m. — using nothing more than the Windows Media Player already loaded on their PCs. The audio/video stunt was good news for WMMR-FM and video technology partner V-Span, both of which saw their Web traffic jump 100 per cent. But it may portend bad news for network administrators in corporate America. Most of the viewers apparently were at work, using their employers' networks to see the webcast during lunch, a V-Span spokesman said. Network managers complain that the rapid growth of streaming media — and downloads of MP3 music files — is robbing corporate networks of valuable bandwidth, causing some companies to consider banning employee access to audio and video Web sites. "Without a doubt, it's a problem, and it's just going to get worse," said Danny Daniels, manager of information systems at Above Board Electronics., a distributor of specialty fasteners and components in San Jose. He said employee use of audio sites had been doubling every two weeks at Above Board until the company announced a music ban in March. "Somebody will download an MP3 file, and we'll have this huge spike in [network usage] and everything will just come to a screeching halt. It's kind of tough, because most people don't really understand the effect" on the company's network, Daniels said. MP3 files are typically 3MB to 5MB per song — not a big deal for huge companies with multiple T3 lines. But for a location served by a T1 line or a fractional T1, "if five to 10 people are downloading a gigabyte of MP3 files over lunch, that's going to be a tremendous load on the network," said John Hedtke, a Seattle-based author of two books on MP3. Besides downloading MP3 files, employees are listening to baseball games, Internet radio stations and music channels offering subgenres such as "acid jazz," "British invasion" or "classic crooners." Last month, BRS Media Inc. in San Francisco counted 3,537 radio webcasters. In fact, hundreds of thousands of at-work employees are visiting music Web sites such as Broadcast.com, MP3.com, Listen.com, Tunes.com and MTV.com, according to Media Metrix Inc. in New York. The Internet radio industry — and its advertisers — are thrilled to reach at-work listeners, who typically have T1 access lines and PCs loaded with sound cards and speakers. And while conventional radio sometimes has a weak signal inside office buildings, Internet radio doesn't have that signal strength problem. "But it cuts both ways," said Bill Rose, an Internet radio expert at The Arbitron Co., a media research company in New York. "Generally, the office has more broadband capability through T1 or T3 lines. But network managers sometimes do restrict access to streamed media because it consumes a good deal of bandwidth." The industry defends Internet radio as a service that provides productivity-enhancing music for office workers — who still can work on their Word documents and Excel spreadsheets while listening. Furthermore, "we stream our music at 20K bit/sec., which takes up an extremely small piece of the pipe," said Mike Romano, vice president of marketing at WWW.com Inc., a music service in Santa Monica, California. A bigger problem comes from Napster.com, a service that helps people share their often-pirated MP3 music files. Each user who downloads the software essentially becomes a Napster server, capable of swapping music with other Napster users. Many universities banned student access to Napster.com after finding that 20 per cent to 60 per cent of their network bandwidth was being eaten up by the MP3 traffic at peak times. Plus, they weren't comfortable having dozens of unauthorized servers full of music files that may violate copyright law. It isn't just a university problem: The Media Metrix study found that 335,000 at-work employees visited Napster.com in March. The next wave of bandwidth-hogging traffic may be video webcasts such as last week's Victoria's Secret fashion show in Cannes, France. "Video really eats up bandwidth. It kills it," noted Samir Bhavnani, an analyst at Computer Economics Inc. in Carlsbad, California. Many companies already have employee Internet usage policies that typically ban visits to pornography sites, online gambling establishments and the like. But they may not have updated their policies to cover audio or video activity that isn't work-related, Bhavnani added. Companies can use a variety of Internet filtering tools to monitor or block certain categories of Web site activity. For example, San Diego-based Websense Inc. recently added — at the request of customers — more than 800 MP3 and audio sites to its database of "inappropriate" Web destinations, a spokesman said. Companies looking for Internet audio enthusiasts can look no farther than their own information technology departments. Several managers said IT workers are the most active MP3 downloaders so far. "I'm probably the worst offender. I have not one but two MP3 players," joked Ron Friedman, director of information systems at Meyer Material Co. in Des Plaines, Illinois. But he said it isn't a problem because the company has a Gigabit Ethernet network, "so it would take quite a bit to bog that down." Arbitron reports that 41 per cent of at-work Internet users have listened to Internet audio at some point — but that isn't all bad. Certain employees may have good business reasons for monitoring audio newscasts or participating in Web conferences, for example. Drawing the line is especially difficult at an entertainment company such as Hollywood's Twentieth Century Fox. There, employees may have a perfectly legitimate reason for downloading a movie trailer from a Web site, said Jeff Uslan, the company's manager of information protection. Nevertheless, Uslan has installed monitoring software from Burlington, Massachusetts-based Elron Software and checks monthly reports to identify workstations making excessive use of music sites. If there isn't a business reason, the offender is asked to stop and the software is uninstalled. Now that 18 per cent of the company's network bandwidth is being gobbled up by music, Uslan said, "we are getting ourselves positioned to block programs like Spinner [from music site Spinner.com] and Napster." Uslan said he has little sympathy for Internet radio listeners at work. "Why in the world would somebody want to eat up your bandwidth listening to radio music over the Internet on PC speakers — when it's cheaper for the company to go and buy stereos for everybody?" Uslan said. "When you look at the cost of what these people are doing in terms of bandwidth and Internet access, it's extremely expensive."