Chapter 2. Pre-install 35
The Ethernet protocol supported by the LAN network should be the DIX Ethernet
Version 2 protocol.
For session throughput reasons, the LAN network should support a minimum MTU size of
576 bytes. If possible, use the maximum supported MTU size of 1492 bytes.
The OSA-ICC server MTU size value does not include the 8- byte Ethernet frame header.
So for LANs supporting 1500-byte Ethernet frames, the OSA-ICC MTU size value should
be set to 1492 bytes. See “MTU Size(B)” on page 25, and Figure 3-7 on page 51.
2.2.4 TN3270E emulator planning
This section describes planning for the TN3270E emulator session configuration parameters.
We recommend that you use the TN3270E configuration worksheet to record the session
parameters for your configuration (see “Worksheet templates” on page 98).
See “Example configuration worksheets” on page 82 for the parameters used in our example
TN3270E emulator program support for the OSA-ICC function
The OSA-ICC function complies with TCP/IP RFC 2355 TN3270E Telnet Option. There are
currently two Telnet TN3270E (
not TN3270) emulator program products that explicitly support
the OSA-ICC function:
IBM Personal Communications (PCOMM) V5.6 and later supports TN3270 Extensions
used for OSA-ICC support. PCOMM is a component of the IBM Access Client Package for
Multiplatforms program suite. For more information, see:
Many PTFs are available for currently supported PCOMM releases, for the TN3270E
function, and especially for 328x emulated printer support. For more information about
PCOMM service updates, see:
IBM Tivoli AF/REMOTE V18.104.22.168 and later supports TN3270 Extensions used for
OSA-ICC support. For more information, see:
Other TN3270E emulators may work with the OSA-ICC function. If you choose to use another
TN3270E emulator, we recommend ensuring that the product vendor provides software
support for the emulator program. Avoid using freeware or shareware programs with no
TN3270E session configuration
The TN3270E client sessions appear to the host operating system as local non-SNA DFT
3270 terminals and 328x printers. The use of a LAN and TCP/IP connections is not visible to
Note: We highly recommend that you apply the latest software maintenance available
for the PCOMM version and release you are running in your OSA-ICC environment.
Note: AF/REMOTE does not currently support the 328x emulated printer function.
Note: IBM supports only Personal Communications (PCOMM) V5.6 for Windows (or later)
and IBM Tivoli AF/REMOTE V22.214.171.124 (or later) for use with the OSA-ICC function.