Win2K IP multicasting faulty?

A U.S.-based research analysis group announced in mid-January that it discovered some potentially troublesome problems with the Windows 2000 IP multicasting feature, but that Microsoft Corp. was quick to correct the problems and issue a patch for users.

Brielle, N.J.-based Tolly Research conducted a hands-on test of the Windows 2000 IP multicast technology when researchers attempted to build an enterprise-scale multicast network and found themselves in what its newsletter referred to as a “multicast morass.”

“In general, what we wanted to do was take a look at the IP multicasting ability within Windows 2000 and see how implementing those capabilities on a local area network or an intranet would impact the overall operations on the local area network,” said Kevin Flood, senior vice-president of Tolly Research.

“Basically, what we found was that the Windows 2000 IP multicasting solution was quite comprehensive and capable, but at the same time, there are a lot of nuances and idiosyncrasies involved in making sure that it is configured properly and interoperable with the hardware that it needs to be interoperable with.”

The IP multicasting function’s purpose is to broadcast Microsoft NetShow videos throughout a corporate network.

Even though he said his team demonstrated that users could implement Windows 2000 IP multicasting in any 32-bit environment, there are a number of configuration and management tools that have to be used to verify compliance of the terminals and to configure them properly.

“Once users are aware of what those tools are and know how to use them, the process goes quite smoothly, and someone with that experience could effectively and efficiently implement the IP multicasting solution,” Flood said. “However, someone not aware of them or unfamiliar with the tools could really spend a lot of time trying to get the solution to work and could easily come to the conclusion that it doesn’t work.”

At the same time, certain registry edits intended to impact functionality were not functional, he said.

Finally, the Windows 2000 IP multicasting scheme is a forwarding scheme and it doesn’t implement any multicast routing, Flood said. Generally, it works well, but in some situations, it actually results in the doubling of the traffic load on some LAN segments.

How much of a problem could the IP multicasting problems cause?

“It depends on how [users] implement the solution,” Flood said. “It could be no problem at all or it could be very significant.” In most network architectures, he said, it’s a non-issue.

According to Erik Moll, Canadian Windows 2000 product marketing manager at Microsoft Canada Co. in Mississauga, Ont., he and his team had not heard of any customer feedback regarding the problems identified by Tolly Research. But even so, the IP multicasting problems are minor and would not affect the majority of Windows 2000 users, Moll said. He added that Microsoft is always open to suggestions for product improvements and that the firm issues patches and the like promptly.

“It’s not a major issue as far as I know,” Moll said. “I have not seen any communications on it. I have not run into any customers that have identified it as an issue.”