System information

Planning Considerations
43
The hardware test is just that, a memory test and other hardware tests to
insure that the Network Station hardware is operational. For the most part,
the length of this test is determined by the amount of memory in the IBM
Network Station.
Table 3. Time (Seconds) to Perform Hardware Test
2. Kernel or configuration initialization
In this step, the Network Station locates the AS/400 server, reads the
kernel and configuration files, and then displays the login window.
The Network Station broadcasts a BOOTP request to locate the AS/400
server and then the kernel (about 2MB) is read using the TFTP function of
TCP/IP. The configuration files are then read using the Remote File
System (RFS). The time to load the kernel using TFTP is heavily
dependent on:
•TFTP block size
• TCP/IP maximum transmission unit (MTU) size
• LAN line description frame size
• TFTP subnet broadcast option number of TFTP jobs
• Number of TFTP jobs
The Network Station negotiates the TFTP block size with the AS/400
server. It can range from 512 to 8192 bytes. The Network Station default is
8192. In general, the Network Station uses the TFTP block size, MTU and
frame size defined by the AS/400 server.
The AS/400 server default TFTP block size is 1024. As shown in the
following tables, best performance is obtained with a large TFTP block size
(such as 8192). If the MTU or frame size is less than 8192 (Ethernet has a
maximum frame size of 1492) performance, can be enhanced by
configuring the block size greater than the MTU or frame size. If the TFTP
block size is greater than the MTU or frame size, TCP/IP fragments
(subdivides) the TFTP blocks to fit into the MTU or frame size. The
Network Station TCP/IP recombines the MTU or frames into TFTP blocks.
This fragmentation provides better performance than setting the TFTP
Memory (MB) Series 100 Series 300 Series 1000
81514-
16 18 18 -
32 24 22 10
48 30 26 -
64 36 31 13