Airlink EDGE/GPRS - Manual (Page 34)

PinPoint-E EDGE/GPRS - User Guide, version 2.32 28
Data Communication and Host Modes
Public and Private Mode
TCP packet assembly is affected by the values of S50 (PAD Forwarding Time-out) and S51 (PAD
Forwarding Character). Data received in the serial buffer will be transmitted when the idle inter-
character time-out specified in S50 (in tenths of seconds) occurs or when a character is received
that matches S51 (if non-zero).
The TCP session will be terminated if no data is transmitted or received for the time interval spec-
ified in TCPT and TCPS. TCPT is the number of minutes (TCPS=0) or seconds (TCPS=1) used
for this idle time-out.
Caution: TCPT should never be 0 when using the TCP mode. A broken TCP ses-
sion can result in the modem being left with a TCP half-open connection that can
only be terminated with a reset.
TCP Auto Answer
TCP auto answer (S0=1|2) also allows a TCP connection request to be "answered" when the
modem is idle, not in a data session. The TCP connection request's destination port has to match
the modem's device port.
Note: UDP auto answer may also be set simultaneously with TCP auto answer.
Then, when in the idle state, the modem will accept either a TCP connection
request or UDP incoming packet, and enter a TCP or UDP session as appropriate.
Hybrid Modes
Some previous hybrid modes (MD=5, 6) are no longer implemented as special, unique modes.
Now that UDP auto answer (UDP Half-open, S82=2) can be enabled in conjunction with UDP
PAD mode (MD3), effectively this is the same as MD5 and MD6 previously accomplished. Set-
ting MD5 and MD6 are still supported, but not recommended.
AT
Command Hybrid Mode
(MD5) Hybrid Mode2
(MD6)
MD 3 3
S82 2 2
S0 1 1
*UDPLAST 0 1
By default, the PinPoint-E is in Public Mode and will pass the IP address assigned by the Your
Wireless Service Provider network to the device connected to its port. If you need more control
over which gateway address, device address, and netmask that is given out by the DHCP server,
you can use the private host mode, *HOSTPRIVMODE, and set the internal network IP
addresses. The PinPoint-E will use NAT to forward packets to the end device.