Sierra Wireless DART 200 CDPD Modem User Manual
Page 80
DART 200 CDPD Modem User’s Guide
5 DART Supported Protocols
Sierra Wireless, Inc.
5-26
3. The DART (registered NEI) IP Address is known to the network and
is obtained from your service provider. This IP Address is set using
the following service provider command: AT^An.n.n.n/x, where: x
defines which slot (0-9) in the address table to use. If not entered, x
defaults to 0.
If there is more than one NEI stored in the modem’s NEI list the
desired one is selected by using the following command: AT\Sn,
where: n = 0 to 9
The IP Address selected for use as the NEI remains fixed until
specifically changed by using the AT\S command.
To view the list of IP Addresses as well as the MAS and SLIP IP
Addresses use the AT\S? command: the active NEI has an * to its
left, for example:
at\s?
SLIP = IP ADDRESS 001.001.001.002
MAS = IP ADDRESS 155.174.048.173
NEI 0 = IP ADDRESS 155.174.036.087
*NEI 1 = IP ADDRESS 155.174.048.173 SPNI 00000 LSA
00000
OK
SLIP operation
The SLIP operation process is as follows:
1. SLIP starts with the
AT*S command.
2. This command puts the modem into SLIP mode and gives an OK
response.
3. When in SLIP mode the DART 200 passes all IP and higher layer
protocols (TCP, UDP, telnet) to the TCP/IP stack in the MAS for
processing, but continues to handle the lower CDPD protocol layers
including the data encryption function. Data forwarding defaults to a
transparent, symbol-based method where the symbol is the SLIP
end-of-packet character.
4. The modem stays in SLIP mode until an escape function is
performed by the end-user application; by either sending the escape
sequence, or by dropping DTR.
5. To return to SLIP mode another AT*S must be issued.
An example of SLIP setup for Trumpet, a commonly available shareware
Winsock, is shown in Appendix D, SLIP Setup Examples.
?
?
NOTE:
•
All three IP
Addresses cannot
be the same
•
For FTP, #1 and
#3 (in Figure 5-1)
must be the same
•
All three can be
different for
non-FTP
communications,
but performance is
somewhat better if
#1 and #3 are the
same