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

Chapter 2 51
Cross-System NetIPC
Calls Affecting the Remote Process
HP 3000 to HP 9000 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 2-4 lists the NetIPC calls affecting the remote
process and summarizes the cross-system considerations.
Table 2-4 Cross-System Calls (HP 3000 — HP 9000
NetIPC Call Cross-System Consideration
IPCCONNECT
Checksumming — When the ipcconnect() call is executed on the HP 9000
node, checksumming is always enabled. Therefore checksumming is always
enabled for the HP 3000-to-HP 9000 connection.
Send and receive sizes — The HP 3000 send and receive size range is 1 to
30,000 bytes. The HP 9000 send and receive size range is 1 to 32,767 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 correct range
for the respective system.
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. On the HP 9000, the default send and receive size is
100 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). Addresses outside of this range require privileged mode access.
IPCLOOKUP
No differences that affect cross-system operations.
IPCRECV
Receive size ( dlen parameter) — Range for the HP 3000 is 1 to 30,000
bytes. Range for the HP 9000 is 1 to 32,767 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.
Data wait flag — The HP 9000 IPCRECV call supports a “DATA_WAIT” flag.
This flag, when set, specifies that the call will not complete until the amount
of data specified by the dlen parameter has been received. This flag is not
available on the HP 3000, meaning that the call may complete before all the
data is received. However, the HP 3000 IPCRECV supports other flags such as
the “more data” and “destroy data” flags. Refer to the description of IPCRECV
in Chapter 3 , “NetIPC Intrinsics,” for more information.