DOCUMENT:Q109555 08-AUG-2001 [winnt] TITLE :Virtual Circuit Error 3193 PRODUCT :Microsoft Windows NT PROD/VER:3.1 OPER/SYS: KEYWORDS:kbusage ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Windows NT Advanced Server, version 3.1 ------------------------------------------------------------------------------- In a mixed Microsoft NT Advanced Server environment with LAN Manager 2.x and OS/2 1.3, where LAN Manager is the Backup Domain Controller to an Advanced Server Primary Domain Controller, the following error message appears in the error log of the Backup Domain Controller: WORKSTATION 3193 11-30-93 08:59pm NET3193: A virtual circuit error occurred on the session to NTSERVER The NCB command and return code is the data. 96 18 This is caused by the Advanced Server parameter Autodisconnect. When an Advanced Server machine Autodisconnects a session, it sends an NBFP Session.End frame with the DATA2 flag (termination indicator) set to 0001 (abnormal) rather than 0000 (normal). This problem does not occur on LAN Manager OS/2 Primary Domain Controllers. The LAN Manager OS/2 Primary Domain Controller sends a Session.End frame with DATA2 set to 0000. This Session.End frame is transmitted as a result of a HANG.UP command, a SEND command that timed out, or some abnormal condition. DATA2 contains the Termination indicator. This two-byte field is used to indicate the type of termination, where X'0000' indicates a normal session end (as a result of a HANG.UP command) and X'0001' indicates an abnormal session end (typically a SEND command has timed out). The following is an example of an Autodisconnect from an Advanced Server machine disconnecting a session created on the OS/2 BDC. Frame Time MAC Source MAC Dest Protocol Description 58 321.045 LCSCOTTSU3 FATMON NETBIOS Session End (0x18) + ETHERNET: 802.3 Length = 60 + LLC: C I-FRAME N(S) = 0x04, N(R) = 0x0E POLL NETBIOS: Session End (0x18) NETBIOS: Length = 14 (0x000E) NETBIOS: Signature = 0xEFFF NETBIOS: Command = Session End (0x18) NETBIOS: Data2 = 0x0001 (abnormal<<