DOCUMENT:Q103444  23-SEP-1993  [W_NTAS]
TITLE   :RAS Server 64 Port Limitation Information
PRODUCT :Microsoft Windows NT Advanced Server
PROD/VER:3.10
OPER/SYS:WINDOWS
KEYWORDS:

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The information in this article applies to:
 
 - Microsoft Windows NT Advanced Server version 3.1
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Remote Access Service (RAS) for Windows NT Advanced Server does NOT
prevent administrators from configuring more than 64 dial-in ports. 
However, the system will not support more than 64 simultaneous
incoming connections. Attempting to do this results in unpredictable
behavior. Microsoft does not support any attempt to exceed 64
simultaneous configured ports.
 
MORE INFORMATION
================

RAS requires that a NetBIOS LANA number be assigned for each dial-in
and each dial-out port. If a port is configured for both, it requires
two LANAs. Port types are assigned in the Network Control Panel
application RAS Configuration screen.
 
   Port type                # of LANAs
   -----------------------------------
   Dial-in                      1
   Dial-out                     1
   Dial-in and Dial-out         2
 
Windows NT has a fixed limit of 72 total NetBIOS LANAs. You should
configure all your RAS ports to consume less than 64 LANAs (see the
above chart). The remaining eight LANAs are generally set aside for
use with other network protocol bindings.
 
This explains why when you look at the NetBIOS configuration in the
Network Control Panel application, you will sometimes see RAS taking
up more LANAs than there are COM ports installed. For example, if you
have a Windows NT Advanced Server with two internal COM ports and you
have configured both ports for dial-in and one port for both dial-in
and dial-out, when you look at the NetBIOS configuration, you will see
three LANAs assigned to RAS bindings.
 
For more information, query on the following word in the Microsoft
Knowledge Base:

   lana 

Additional reference words: 3.10
KBCategory:
KBSubCategory: ntrmt

=============================================================================

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Copyright Microsoft Corporation 1993.