Airlink X EV-DO - Manual (Page 30)

Raven X EV-DO for Verizon - User Guide, version 2.34 24
Data Communication and Host Modes
TCP PAD
When the Raven X is in a TCP session, all characters received on the serial port are assembled
into TCP packets and sent to the mode's remote IP address/port, and any packets received from
the remote end of the TCP connection are disassembled and dumped onto the serial line.
A TCP connection is established by one of the following methods:
• Using the Dial TCP (DT) AT command (for example, ATDT192.168.3.23/3456)
• TCP auto answer is enabled (S1), a TCP connection request is received, and the modem is not
in a data session.
• Data is received on the serial port and
• The Startup Mode Default (MD) is 4 (auto TCP)
• The remote TCP destination, as defined in S53, successfully responds to the TCP connection
request.
The value of S7 (TCP Connection Time-out) specifies the number of seconds to wait, after initiat-
ing a TCP connection attempt, for a successful connection to be established. If the connection has
not been successfully established before the time-out occurs, ERROR/BUSY is returned.
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.
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