Data Communication and Host Modes
RLXIC-SV
♦
Intelligent Cellular
User Manual
RadioLinx Intelligent Cellular Serial Modem for the Verizon Wireless CDMA Network
ProSoft Technology, Inc.
Page 63 of 146
May 29, 2009
7.3 Serial
Modes
7.3.1 PPP
In PPP mode, the RLXIC-SV acts as a PPP server, providing an IP address, and
DNS servers (if available) to the connected device or computer.
PPP mode is entered from the AT mode by using any of the following
commands:
AT\APPP
ATDT10.0.0.1
ATDT10001
ATD#19788 or #777 *99***1#
CLIENT
In response to any of the preceding commands, the RLXIC-SV will respond with
CONNECT a carriage return and new line and is ready for the host to begin PPP
negotiations. The IP received by the host in the resulting negotiation will either be
a private (non-routable) IP address or a public (network-routable) IP address
provided by the network, depending on the settings of
*HOSTPRIVMODE
. If
*HOSTPRIVMODE=1
, the value of the private IP address can be determined
beforehand by querying
S110
. The private IP address to be used can be defined
with the command
AT*HOSTPRIVIP=192.168.100.33
, substituting the desired IP
address.
Using a private IP insulates the PPP client from changes in IP addresses of the
underlying network. The will perform basic NAT-like address translation on all
packets.
If a public IP address is being used, any changes in the IP (as determined by the
wireless network) will result in the PPP link to the host being disconnected,
requiring the host to reinitiate it. The public IP is passed to the host in the PPP
negotiations, so when the network forces a change, the modem has to force the
host to renegotiate the PPP link to make this happen.