NetIPC 3000/XL Programmer's Reference Manual (5958-8600)

Chapter 2 53
Cross-System NetIPC
Calls Affecting the Remote Process
HP 3000 to PC NetIPC
The NetIPC calls affecting cross-system communication with the
remote process have the following differences: checksumming, send and
receive sizes, range of permitted TCP protocol addresses for users, and
socket sharing. Table 2-5 lists the NetIPC calls affecting the remote
process and summarizes the cross-system considerations.
Table 2-5 Cross-System Calls (HP 3000
— PC)
NetIPC Call Cross-System Considerations
IPCCONNECT Checksumming — With PC NetIPC, the TCP checksum option cannot be
turned on. But if the HP 3000 requires it, the TCP checksum is in effect on
both sides of the connection.
Send and receive sizes — The HP 3000 send and receive size range is 1 to
30,000 bytes. The PC send and receive size range is 1 to 65,535 bytes.
Although the ranges are different, cross-system communication is not
affected. If you specify a send or receive size, be sure it is within the correct
range for the respective system. For example, if the PC node sends 60,000
bytes, the HP 3000 node can call IPCRECV twice, receiving the first 30,000
bytes the first time and the second 30,000 bytes the second time.
Note that the default send and receive sizes are different on different HP
systems. On the HP 3000, the default send and receive size is less than or
equal to 1,024 bytes.
IPCCREATE
IPCDEST
TCP protocol address — The recommended range of TCP addresses for
cross-system user applications is from 30767 to 32767 decimal (%74057 to
%77777).
IPCRECV Receive size ( dlen parameter) — Range for the HP 3000 is 1 to 30,000 bytes.
The PC send and receive size is 1 to 65,535 bytes. Although the ranges are
different, cross-system communication is not affected. If you specify a send or
receive size, be sure it is within the correct range for the respective system.
On the PC, you can specify the maximum receive size of the data buffer
through the got array in the IPCCONNECT call. This determines what the
maximum value for dlen can be for any IPCRECV call. PC NetIPC has no
option array defined in IPCCONNECT. This does not affect cross-system
communication. The maximum receive size of the data in the buffer on the
HP 3000 will determine the receive size buffer on the PC.