Microsoft KB Archive/66937

NETBEUI Transport in LAN Man 2.0 Doesn’t Support DLC Interface ID Number: Q66937

2.00 OS/2

Problem:

I am having the following problems that involve DLC support:


 * 1) I’m trying to run a program that uses the DLC interface (Attachmate, IBM terminal program, etc.) on my OS/2 LAN Manager version 2.00 DOS workstation. However, the program will not communicate with the host: I get errors that include indication of insufficient SAPs.
 * 2) We recently upgraded from 3Com’s 3+Open 1.x to Microsoft OS/2 LAN Manager version 2.00 (or 3Com LAN Manager 2.0). Our DLC requisite programs that ran fine on 3+Open 1.x will not run on OS/2 LAN Manager version 2.00.

Response:

The information included below describes why the problems listed above are occurring.

The transport stack that was provided in OS/2 LAN Manager version 1.00 consisted of two components. The first component was a “NetBEUI” transport module that would bind to the second component, an 802.2 “DLC” logical link control module. The DLC module would bind to the MAC driver.

This stack was made by Madge Corp. and has been referred to as the “Madge Stack.” 3Com’s 3+Open 1.x product, an implementation of OS/2 LAN Manager versions 1.x, included the Madge Stack, and several customers took advantage of the DLC interface to run DLC requisite applications.

OS/2 LAN Manager version 2.00 does not include the Madge Stack. The transport stack included with OS/2 LAN Manager version 2.00 is NetBEUI, a single component module that binds directly to the MAC driver. NetBEUI does not provide full DLC, and does not have the DLC interface. Therefore, DLC requisite applications that ran OS/2 LAN Manager versions 1.x with the Madge Stack will not run on OS/2 LAN Manager version 2.00 with the NetBEUI transport stack.

Microsoft plans to include a full, IBM compatible DLC interface in OS/2 LAN Manager version 2.10.

A customer may opt to continue using OS/2 LAN Manager versions 1.x on workstations that require the DLC interface while upgrading servers and other workstations to OS/2 LAN Manager version 2.00.

This could provide an interim solution until OS/2 LAN Manager version 2.10 becomes available.