Tun Plus

Innovative Access Management

For organizations that require broader integration or flexibility to deploy via multiple technologies, Esker offers Tun Plus for complete enterprise resource access. Incorporating two powerful solutions ― PC-to-Host and multi-user Windows - Tun Plus offers true innovation in host access and host access management.

By choosing the Tun Plus License, organizations can deliver host access to every user, at any client device, on any platform and at any location. This breadth of delivery is made possible by Esker's redesign of Tun Plus as one product embracing two solutions:

  • Tun Plus PC-to-Host: Unrivaled host, database, and network-utilities access from any PC running Windows ® 10, 8 or 7
  • Tun Plus multi-user windows: Complete access for virtually any client type via Microsoft ® Windows Server ® with Remote Desktop Services

Tun Plus allows organizations to keep pace with the latest developments in connectivity and provide all users - green- screen power users, occasional Windows-style users, or mobile and remote users ― with the right level of access to business-critical information resources.

An innovation in host access management, Tun Plus helps organizations consolidate all host access needs under one product and vendor, relieve system administrators, support personnel and reduce the costs of providing host access.

Complete Tun Plus

Tun Plus delivers comprehensive host access plus broad connectivity to leading databases and critical network utilities.

Customizable terminal emulation

Tun Plus provides terminal emulation for more than 30 host types, including IBM ® 3270 and 5250 - as well as full 3287 and 3812 printer support ― HP ® , DEC ® VT, SCO ® Unix and more.

Powerful Tun Plus customization tools let administrators create user-friendly Windows-style emulation views - adding colors, graphical toolbars and function-key panels, mouse support and clickable hot spots. Customization is easy with drag-and-drop keyboard mapping and over 340 programmable actions.

Network utilities

Tun Plus also includes TCP/IP connectivity to critical network resources. FTP makes file and printer sharing easy. Also included are a full range of server-based components - FTPD and RSHD.

Shared Technologies

As user populations or deployment needs evolve, Tun Plus helps organizations manage the change. Shared technologies unify the PC-to-Host and multi-user Windows solutions, and enable easy migration for user, administrator and IT manager.


All solutions feature a tabbed Workspace that allows users to launch multiple sessions from diverse hosts at one time. The multi-document Workspace promotes productivity by streamlining information integration.

Full-featured clients

All two solutions offer the same full-featured clients - with graphical toolbars, keyboards, client-side macros and other user-oriented functions


Tun Plus safeguards the access of sensitive host data with a range of security offerings to help meet government, healthcare or other industry security regulation requirements.

  • SSH (Secure Shell)
  • TLS (Transport Layer Security)
  • SSL (Secure Sockets Layer)
  • SFTP (Secure File Transfer Protocol)
  • SCP (Secure Copy Protocol)
  • X.509 certificates

Technical specifications

Synchronous terminal emulations

  • Emulations supported:
    • 3270 models: 3278 display (models 2, 3, 4, 5); 3279 display (models 2A, 2B, 3A, 3B).
    • 3270 printer: 3287 supporting SCS (LU1), DSC (LU3), transparent modes, and basic PCL.
    • 5250 models: 3179-2, 3296-A1, 5251-11, 5291-1, 5292-2, 3180-2, 3477-FC, 3477-FG.
    • 5250 printer: 3812 in SCS (LU1), transparent modes, host print transform.
  • Connectivity: TN5250, TN5250E, TN3270, TN3270E; native connections to Microsoft Host Integration (SNA) Server and intraNetWare for SAA gateway.
  • HLLAPI support emulation) (PC-to-Host, multi-user Windows/3270
  • Extended attribute support (3270 emulation)
  • Multiple IND$FILE file transfers with host data set browsing.
  • Enhanced firewall support via NVT mode (5250 emulation).
  • Euro character support.
  • Eastern European character set support.

Asynchronous terminal emulations

  • Emulations supported:
    • Hewlett-Packard ® HP 2392A, 2394, 700/92, 700/94, 700/96, 700/98.
    • DEC VT 52, 100, 220, 320, 420, 520.
    • SCO ® ANSI and ANSI
    • IBM 3151 and HFT.
    • Bull ® DKU 7102/7202 (SDP, VIP modes).
    • Wyse ® 50 and 60, Unisys ® TO300, Philips ® TM266, Minitel ® , Siemens ® BA80-08 and 97801, Linux ® console, Interactive Unix console AT386, Alcatel ® APX AT300, Fortune FT, Data General ® Dasher D412
    • Connectivity: TCP/IP, NVT/IPX, Int 14h, Int 6Bh, serial connections (COM1-COM32), modem auto-dial, TAPI
    • 350 configurable actions (function keys, control codes, escape sequences, character sets)
    • Euro character support (VT, SCO, IBM 3151, Siemens 97801)
    • File transfer: X, Y, Z modem, Kermit, RTUNPLUS
    • Illustrated samples of Visual Basic ® , Visual Basic .Net, Delphi ® and JScript
    • Documented API: with 30 objects described.

    Network utilities

    • SFTP client and FTP client & server-
    • Network tools: TFTP client, Telnet VT320, RSH/REXEC command.
    • RSHD command server, WALL & WALLD (broadcast capabilities), TIME (time synchronization via TIME, SNTP protocols), PING, TAR (PC backup)
    • SCP, a safe alternative to file transfer.


    • DSA authentication
    • Diffie-Hellman key agreement
    • X.509 certificates (generic certificate included; personalized certificates available)


    • 133 MHz or higher Pentium-compatible CPU.
    • 128 MB RAM and 60 MB of disk space.
    • Microsoft Windows with latest Windows update:
      • Windows ® 10 32-bit and 64-bit.
      • Windows ® 8 and 8.1 32-bit and 64-bit
      • Windows ® 7 SP1 32-bit and 64-bit
      • Windows Server ® 2012 and 2012 R2
      • Windows Server ® 2008 R2 SP1
    • In case of installation on Microsoft Windows Server with Remote Desktop Services, sufficient memory and disk space should be available.

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