Ref: 17300010
Title: Cause of Type 3 XNS Error Packets
date: 7/1/90

Copyright 3Com Corporation, 1991.  All rights reserved.

Type 3 XNS error packets are often seen on the network.  They occur
when SPP rejects an XNS connection request.

For example, an application program issued a NetBIOS CALL to a node,
correctly using one of the network names that the node had registered in
the Locator.  The CALL command could not be completed, however, because
there was no corresponding LISTEN command outstanding on the netstation
being CALLed.  The CALL command received the NetBIOS error code 12H,
"Session open rejected."

A "CALL without LISTEN" condition is generated by the NetBIOS application;
it is not an XNS network problem.  To avoid this condition, the NetBIOS
application must wait until a LISTEN command has been issued at the remote
netstation before submitting the CALL command.

