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

50 Chapter2
Cross-System NetIPC
Calls Affecting the Remote Process
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 1000 is 1 to 8,000 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 1000 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.
IPCRECVCN Checksumming — TCP checksumming will be enabled for both sides of
the connection if it is enabled by either side for HP 3000 to HP 1000
connections. On both the HP 3000 and HP 1000 checksumming can be
enabled by setting bit 21 in the flags parameter.
Send and receive sizes — The HP 3000 send and receive size range is 1 to
30,000 bytes. The HP 1000 send and receive size range is 1 to 8,000 bytes.
For example, if the HP 3000 node sends 16,000 bytes, the HP 1000 node can
call IPCRECV twice, receiving 8,000 bytes the first time and the second
8,000 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. On the HP 1000 the default send and receive size is
100 bytes.
IPCSEND
Send size — The HP 3000 send size range is 1 to 30,000 bytes. The
HP 1000 send size is 1 to 8,000 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. Note
that the urgent data bit is not supported on the HP 1000; however, if this bit
is set by the HP 3000 program, it will be ignored by the receiving process on
the HP 1000.
IPCSHUTDOWN
Socket shut down — The HP 3000 provides a graceful release flag
(flag 17) that is not available on the HP 1000. Do not set the graceful
release flag on the HP 3000. Otherwise, the HP 1000 will not perform a
normal shutdown.
Table 2-3 Cross-System Calls (HP 3000 — HP 1000)
NetIPC Call Cross-System Considerations