Airlink Raven GPRS - Manual (Page 41)

Cingular GPRS Raven User Guide Version 2.01 33
Host Modes
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 sec-
onds) 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 specified in TCPT and TCPS. TCPT is the number of minutes (TCPS=0)
or seconds (TCPS=1) used for this idle time-out.
Warning: TCPT should never be 0 when using the TCP mode. A broken
TCP session 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 desti-
nation 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. Setting MD5 and MD6 are still sup-
ported, but not recommended.