Several companies say their networking software isn't compatible with Apple Computer's new operating system, and some blame changes made to the kernel of Mac OS X. A number of the products in question are VPN programs that allow one to connect to a corporate network. Cisco Systems said last week that its VPN software wasthe latest version of the Mac OS that .
Other networking products are also affected, including two from Thursby Software. Thursby chief technology officer Paul Nelson said that with Tiger, Apple created a new set of kernel programming interfaces that change the way the operating system works with software written directly to its kernel. The move rendered obsolete some longstanding Unix networking program methods, known as Berkeley protocol stacks.
"Now we have to go back and redesign our kernel extensions to work with Tiger, which is a major job for us," Nelson said.
The software maker hopes to have updated versions of its of ADmitMac and DAVE products by August.
Microsoft is also reporting problems with the Virtual Switch networking feature of its Virtual PC software. Also, Microsoft said its zero-configuration printing and ability to launch PC programs via the dock is impacted.
"Microsoft is working closely with Apple to address issues and will put out a patch within two to three months on www.microsoft.com/mac," a Microsoft representative said in an e-mail.
Other vendors have reported problems, as well. Lobotomo Software reported Tiger-related problems with its IPSecuritas VPN software.
Equinux warned on its Web site that its VPN Tracker software also won't work properly with Tiger.
"In extensive tests we confirmed that Mac OS X 10.4 Tiger has a bug that seriously affects the VPN performance," the company said. "Depending on the actual application, the VPN throughput under Tiger is about 50 to 75 percent lower than under Mac OS X 10.3 Panther."
Equinux said it can't solve the problem, calling it a bug in the Tiger kernel. "However, we're closely working with Apple to deliver a fix soon."
Apple declined to comment specifically on what changes were made to Tiger's kernel, but said in a statement late Tuesday that it is "working closely with those few developers that have some work to do to update their applications for Mac OS X Tiger."