nstrtel(5)                                                       nstrtel(5)
                          Tunable Kernel Parameters



 NAME    [Toc]    [Back]
      nstrtel - specifies the number of telnet device files the kernel can
      support for incoming telnet sessions

 VALUES    [Toc]    [Back]
    Failsafe
      60

    Default    [Toc]    [Back]
      60

    Allowed values    [Toc]    [Back]
      Any positive integer. (Subject to available physical memory.)

      It is best to use the default value, and there should not be any need
      to lower it.  However, if the simultaneous telnet connection load is
      very high, then the value of nstrtel could be increased.

    Recommended values    [Toc]    [Back]
      60 (Default value.)

 DESCRIPTION    [Toc]    [Back]
      The telnet daemon uses two STREAMS-based pseudo-terminal drivers (telm
      and tels).  The kernel parameter, nstrtel, can be used to tune the
      number of pseudo-terminals.  nstrtel specifies the number of kernel
      data structures that are created at system boot time that are required
      to support the device files used by incoming telnet sessions on a
      server.  If the insf command or SAM is used to create more telnet
      device files, the value of nstrtel must be increased accordingly or
      the device files cannot be used because there are no kernel data
      structures available for communicating with the system.

    Who Is Expected to Change This Tunable?
      Anyone.

    Restrictions on Changing    [Toc]    [Back]
      Changes to this tunable take effect at the next reboot.

    When Should the Value of This Tunable Be Raised?
      When there is an increase in the load of telnet connections and there
      are no device files available to open telnet connections, then this
      kernel parameter should be increased.

      When the telnetd:  Telnet device drivers missing:  No such device,
      error is encountered, then the device files have been exhausted and
      nstrtel should be raised.  Once the value of nstrtel is raised, insf
      should be run to create new device files.  (If SAM is used to raise
      the value of nstrtel, insf is run automatically.)

    What Are the Side Effects of Raising the Value of This Tunable?
      More resources would be consumed.  Extra kernel data structures, and



 Hewlett-Packard Company            - 1 -      HP-UX 11i Version 2: Sep 2004






 nstrtel(5)                                                       nstrtel(5)
                          Tunable Kernel Parameters



      extra device files may clog the system.

    When Should the Value of This Tunable Be Lowered?
      It is not advisable to lower the tunable value from the default value.
      Consult HP Support before lowering this tunable from the default
      value.

    What Are the Side Effects of Lowering the Value of This Tunable?
      Though not recommended, there would not be any side effects.

    What Other Tunables Should Be Changed at the Same Time?
      None.

 WARNINGS    [Toc]    [Back]
      All HP-UX kernel tunable parameters are release specific.  This
      parameter may be removed or have its meaning changed in future
      releases of HP-UX.

      Installation of optional kernel software, from HP or other vendors,
      may cause changes to tunable parameter values.  After installation,
      some tunable parameters may no longer be at the default or recommended
      values.  For information about the effects of installation on tunable
      values, consult the documentation for the kernel software being
      installed. For information about optional kernel software that was
      factory installed on your system, see HP-UX Release Notes at
      http://docs.hp.com.

 AUTHOR    [Toc]    [Back]
      nstrtel was developed by HP.

 SEE ALSO    [Toc]    [Back]
      insf(1M), telnetd(1M), telm(7), tels(7).


 Hewlett-Packard Company            - 2 -      HP-UX 11i Version 2: Sep 2004