
APAR= II09707
PRINTING CONSIDERATIONS WHEN USING CA/400 ON TCP/IP NETWORKS


** Last updated 9/18/96 **

Printing functions vary depending upon which AS/400 Client
Access client you are using and which network protocol you are
running.  Client Access currently supports the following network
connections and protocols:

     o APPC over an SNA network (native SNA support)
       -    Twinax, asynchronous, SDLC, X.25, Token-Ring LAN,
            Ethernet LAN, NetWare for SAA, SNA Server

     o TCP/IP over a TCP/IP network (native TCP/IP support)
       -    Token-ring, Ethernet, SLIP

     o APPC over a TCP/IP network (APPC support using AnyNet)
       -    Token-ring, Ethernet, SLIP (asynchronous dial-up)

 When using AS/400 Client Access for your printing needs, three
 different types of printing capability are provided:

 1. Printing PC application output to an SCS or IPDS printer
    which is either directly attached to the AS/400 or one that
    can be LAN-attached to the network.

    o This is most easily accomplished by using the Client
      Access Network Print (often called Virtual Print) function
      which enables end user to identify an AS/400-type printer
      as their networked printer.
    o Client Access ships both SCS drivers and Advanced Function
      Print (AFP) drivers which convert popular PC output
      datastreams (those generated by PC word processors,
      presentation builders,etc) to AS/400-supported datastreams
      prior to placing them on the AS/400 Spool.  The AFP driver
      also integrate OS/400 fax capabilities into the Network
      Print support.
    o All the Client Access clients provide this support over al
      supported network connections.

 2. Print AS/400 application output on a PC printer.

    o This is typically provided through 5250 Printer
      Emulation (ie, PC5250 or RUMBA/400 or WSF).  In this case,
      AS/400 SCS or AFP/IPDS printer output is converted to a
      datastream format that a PC printer understands.  This can
      be done on the AS/400 by using Host Print Transforms (HPT)
      or on the PC by using local print drivers which are either
      shipped with Client Access or provided by the PC operating
      system.
    o All the Client Access clients provide this support when
      running over SNA/APPC Networks.
    o When running on a TCP/IP network, 5250 Printer Emulation
      (ie, PC5250 and RUMBA/400) can only be used if you are
      using AnyNet.  Printer Emulation is not provided over
      native TCP/IP because the AS/400 server for TCP/IP display
      emulation is a Telnet server which provides TN5250 support
      This support is different than the APPC passthru support
      that is used for native SNA/APPC or TCP/IP (with AnyNet)
      networks.  The TN5250 protocol, as defined by the TCP/IP
      standards, does not provide printer support.  Thus, there
      is no TN5250 Printer Emulation function on the AS/400.
      Conversely, when connecting to AS/400 systems via SNA/APPC
      or TCP/IP via AnyNet, Printer Emulation uses the SNA
      passthru server on the AS/400 which has the printer
      support. See the options listed below for providing
      solutions to this problem.  The following clients support
      TCP/IP using AnyNet: when running over TCP/IP Networks
      using AnyNet (MPTN)
          -- Client Access for Windows 3.1
          -- Client Access Optimized for OS/2
          -- Client Access for Windows 95 (available 11/8/96,
               refer to programming announcement 296-305
               dated 9/3/96).

 3.  Redirect PC application output via the AS/400 Spool file
     to another PC printer in the network.

     o This is accomplished by using both Client Access
       functions above.  Network Print is used to forward PC
       output to the AS/400 Spool file, then 5250 Printer
       Emulation is used to print that output on a Client
       Access user's attached PC printer.
     o See 1. and 2. above for client and network support.

--------------------------------------------------------------
Options for printing AS/400 output on your PC-attached printer
in a TCP/IP Network
--------------------------------------------------------------
Since the Windows 95 client supports native TCP/IP and soon
TCP/IP over AnyNet network connectivity, the following
alternatives are available to Windows 95 users when trying to
decide how to send AS/400 printer output to a PC-attached
printer in a TCP/IP network.

1. Use LPR/LPD (Line print requester/Line print daemon) to run
   natively in TCP/IP networks.

   In the TCP/IP world, LPR/LPD is the standard solution for
   print files.  OS/400 provides an LPR function which can be
   used to route AS/400 output to a remote printer queue.
   This function is used as an alternative to printer
   emulation for printing AS/400 output to PC printers.

   The OS/400 LPR function communicates with an LPD function
   on the PC, which is typically available with the TCP/IP
   stack.  Client Access for Windows 95 relies on the 32-bit
   TCP/IP stack shipped with Microsoft Windows 95 OS; however,
   this stack does not provide LPD support.  Options available
   are:

   a. Obtain a TCP/IP stack which includes LPD.  Client Access
      can run on other 32-bit TCP/IP stacks if they are
      compatible with the WinSock interface.

   b. Obtain an LPD which is compatible with other 32-bit TCP/IP
      stacks.  Some examples are:

      o NIPrint from Network Instruments.
                  http://www.netinst.com
      o Remote Print Manager (RPM) from Brooks Internet Software
                  http://www.brooksnet.com/rpm.html

      Both provide free evaluation periods.

   c. Check the Microsoft web site for information on TCP/IP
      stacks and LPD offerings.

   PLEASE NOTE:  IBM does not in any way recommend or endorse
   any particular solution.

   Configuration is unique for LPR support on AS/400.  The user
   must create a remote output queue and then start the remote
   print writer.  Sources for information about configuration
   and setup can be found in:
       --OS/400 TCP/IP Configuration and Reference, Version 3,
         SC41-3420
       --IBM Redbook 'AS/400 Printing III'
       --News3X/400 May 1995 article by Gary Mullen-Schultz
         entitled 'AS/400 Printing with V3R1'
       --News/400 March 1996 article by David Brim entitled
         'AS/400 Printing with LPR/LPD'

   Below are some other points to consider are:

   o  Advantages of using LPD are:
      --LPDs have a relatively small footprint on the PC
        because they expect to receive print files in ASCII
        format.
      --Since LPDs only work with ASCII format, the OS/400
        Host Print Transform (HPT) must be used to transform
        the entire print file before transmission to the PC
        printer.

   o  Disadvantages of using LPR/LPD are:
      --Customers must acquire an LPD and insure the LPD works
        well with the OS/400 LPR.  Compatibility will vary with
        the choice of the LPD.
      --Some LPDs ignore the control file that is sent with the
        print file.  Control files contain information such as
        the number of copies desired or if separator pages
        should be printed.  If the control file is flushed, the
        information is lost.
      --If an error occurs on the transmission of the spoolfile,
        the TCP/IP reported error will cause the LPR to
        continually retry the transmission until the
        transmission is sent or the spool file is held.
      --Once the file transmission is completed, the OS/400
        assumes the LPD will successfully print the file.
        However, successful transmission does not equate to
        successful printing of the file.
      --Cancelling of a print job from the AS/400 during the
        transmission of a print file will have unpredictable
        results.

   o  Advantages of using HPT are:
      --Since all conversions are done by HPT, consistency of
        printed output across destination printers is provided.
      --HPT may provide additional conversion support not
        commonly associated with 5250 emulation.  For example,
        HPT supports transforming SCS (text) to ASCII and also
        supports transforming AFP (which includes bar codes,
        images, etc...) to Hewlett Packard's PCL and it can
        also generate TIFF (a popular format for image data).

   o  Disadvantages of using HPT are:
      --HPT uses system resources which may be noticed by other
        users (especially for very large documents).
      --Each print file sent to the PC requires a job
        initiation on the AS/400.  If there are many small
        files being sent to a PC the system resources consumed
        may be noticed by other users.

   o  Users accustomed to using Printer Emulation may notice
      the following differences when using HPT as well:
      --Printer Emulation prints on a page-by-page basis, thus
        users will recognize that their printer does not begin
        printing the document as early.
      --COR (Computer Output Reduction) is implemented
        differently across emulators, thus HPT may prepare it
        differently than a particular 5250 Printer Emulation
        program would have.
      --Printing of selected pages is not possible; this
        capability is particularly desirable on large documents.
      --Printer Emulation often fully supports HP PCL6 printers,
        whereas HPT provides PCL5 level of support.

2. Run Printer Emulation over SNA/APPC protocol and rest of
   client function over native TCP/IP protocol.

   o  Advantages are:
      --PC5250, a full-function Printer Emulation is provided
        with Client Access at no additional charge.  Since
        PC5250 is an integrated function of Client Access,
        fixes and new releases can be ordered and applied
        through Client Access mechanisms.
      --PC5250 can perform transformations to the ASCII
        datastream at the PC thus reducing AS/400 resource
        utilization.

   o  Disadvantages are:
      --Requires multiple protocols to flow across the LAN.
        This may not be acceptable, particularly when
        bridges/routers are present in a WAN environment, as
        both SNA/APPC and TCP/IP must be configured on the
        AS/400.
      --End user must configure both TCP/IP and NetSoft router
        on the PC, and running both a TCP/IP stack and the
        NetSoft router results in larger memory usage on the
        PC.

3. Run PC5250 Printer Emulation over TCP/IP via AnyNet
   (when available).

   o  Advantages are:
      --Only the TCP/IP protocol needs run across the network.
      --PC5250, a full-function Printer Emulation, is provided
        with Client Access at no additional charge.  Since
        PC5250 is integrated with Client Access, fixes and new
        releases can be ordered and applied through Client
        Access mechanisms.
      --PC5250 can perform transformations to the ASCII
        datastream at the PC thus reducing AS/400 resource
        utilization.
      --Any EHNAPPC or CPI-C application or any 16-bit
        applications written to Windows 3.1 or DOS Extended
        APIs can run transparently over a TCP/IP network.

   o  Disadvantages are:
      --Running both a TCP/IP stack and an SNA/APPC router
        with AnyNet results in larger memory overhead on the
        PC than selecting option 2 above.
      --Both TCP/IP and AnyNet must be defined on the AS/400
        which increases OS/400 overhead.
      --Using an SNA/APPC router with AnyNet may not perform
        as well as either native TCP/IP or running just a
        native SNA/APPC router.


