Release Notes 93000160
for
Digi RealPort Service for Windows NT(r) 3.51 and 4.0
Software Package P/N 75000527
Diskette P/N 40001738 V1.0.3 (3.5")

Copyright 1998 Digi International, Inc.

This document describes the installation, configuration and features of the 
Digi RealPort service.  This product  includes support for Windows NT 
versions 3.51 and 4.0.

Contents
Section	Description
1		Introduction
2		Known Limitations
3		Known Problems
4		Installing the Modem 4em or Modem 8em module
5		Changing the TCP Window Size
6		Printer Note
7		Bug Fixes
8		If You Have Problems
9		Removing the Driver
10		Release History

1  Introduction

The RealPort service provides access to serial ports on Digi's PortServer or 
PortServer II products as if the ports were physically contained within the 
host system and controlled by the Microsoft Windows NT operating system.  

The Digi PortServer Product family allows Windows NT users to attach serial 
devices (modems, terminals, and printers) to the Ethernet based terminal 
server.  Users can use Windows NT RAS, Windows NT based Citrix, dial-out
modem pooling applications (e.g. SAPS, Net2Com, WinPort) and terminal
server applications such as Point-of-Sale (POS) with the flexibility of
terminal server connected devices.

The RealPort Service requires the TCP/IP driver to be installed and properly 
configured.

2  Known Limitations

Software flow control characters when set to the null (0x00) character for the
Xon and Xoff character will be ignored by the driver.

IOCTL_SERIAL_XOFF_COUNTER will not be supported.

3  Known Problems

* Windows NT 3.51 with Service Pack 5 can be made to hang when running 16 ports
  full duplex at 57600 or 115200 BAUD.  This hang was also simulated 
  by generating network traffic aimed at the test system in an idle state, 
  without the RealPort Service loaded.
* PortServer generates receive data errors when running 16 ports full 
  duplex at 57600 BAUD.
* Changing the baudrate of a serial printer requires deleting the printer 
  device and then re-adding the device with a different   baudrate. 
  (Print manager limitation in Windows NT 4.0.)

4  Installing the Modem 4em or Modem 8em module

Windows NT 3.51

For RAS support the file, modem.inf located on the RealPort installation disk,
must be copied into the system's RAS directory if a modem.inf file doesn't 
already exist in your system; or Digi's modem.inf file contents must be 
merged with an existing modem.inf file. located in %SystemRoot%\System32\RAS.

Windows NT 4.0

The file, mdmdigi.inf located on the RealPort installation disk, must be copied
into the directory %SystemRoot%\INF.

5  Changing the TCP Window Size

Network performance is limited to the size of the TCP window.  The default TCP
Window Size is 8760.  The best performance found during testing under Windows 
NT 3.51 with Service Pack 5 and Windows NT 4.0 utilized a TCP window size of 
13140.  To change the default TCP window size you must use regedt32 to add a 
REG_DWORD TcpWindowSize key value at 
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters.

6  Printer Note

Printers using the RealPort driver should be manually started, or the RealPort
driver must be started before the printer services.

7  Bug Fixes


i.	The device names in the SERIALCOMM key will be changed  to map to the actual
	device name.

ii.	Additional keys added to the driver for  configuration of CtimeOut, Tmax and
    TTime parameters.

iii.Changes made in  serialpurge, waitonmask and setwaitmask routines to be 
	conformant	with the standard NT serial  port driver.





8  If You Have Problems...

1.	Note exact wording of error messages you receive.
2.	Try to reproduce the problem, if possible.
3.	Contact Digi Technical Support via:
	Phone:		612-912-3456
	FAX:		612-912-4958
	BBS:		612-912-4800
	E-mail:		support@dgii.com


9  Removing the Digi RealPort Service

Windows NT 3.51

1.	Run Control Panel | Network 
2.	Select the Digi RealPort Service  from the Installed Network Software list.
3.	Choose Remove.

Windows NT 4.0

1. Run Control Panel | Network 
2. Select Services
3. Select the Digi RealPort Service  from the Network Services list.
4. Choose Remove.


10  Release History

Version 1.0.1
July 21, 1997 - Initial product release.

Version 1.0.2
November 7, 1997 - Bug fixes.

Version 1.0.3
August  25, 1998 - Bug Fixes