User guide

Raven EDGE/GPRS for Cingular - User Guide, version 2.31 123
Frequently Asked Questions and Technical Support
However, if you need to be able to contact your Raven (or the devices behind it) directly, instead
of a Restricted IP (also called Private IP, Non-Routable IP, or Proxy APN), you will need to
contact Cingular your cellular provider to get your account changed to an Unrestricted IP (also
called Public IP or Internet APN).
Note: Customized APNs are generally private and non-routable.
What is the difference between Private and Public mode?
When your Raven is powered on, ALEOS, acting as a PPP client, negotiates a PPP session with
Cingular’s network at the conclusion of which it is assigned an IP address by your cellular pro-
vider. How this address is further acted upon by the modem
is determined by Private or Public
Mode.
Public Mode (*HOSTPRIVMODE=0):
The IP address assigned by Cingular is passed on
to the devices connected to the modem.
If there is a computer or device connect
ed to the serial port of your modem, there are actually two
PPP sessions taking place. After your modem receives Cingular assigned IP address, a second
PPP session is established between your computer or device and the modem ultimately assigns
that IP address to that computer or device connected to the serial port.
Private Mode (*HOSTPRIVMODE=1):
The IP address assigned by Cingular is not the address that is assi
gned to
the computer or device
connected to the Raven’s serial port during the PPP negotiation or DHCP IP assignment. Instead,
the computer or device connected to the Raven on the serial port is assigned the IP address config-
ured in *HOSTPRIVIP and uses the IP address configured in
*
HOSTPEERIP to communicate to
the modem.
How do I set up Private Mode? How do I connect to my Raven to my router or
to Linux?
Private Mode is at times preferred or required to provide network connectivity to a Linux device,
routers, or other devices. Private mode will generally also work with any PC in an environment
where there is a need for the Raven to be configured to work with an internal network.
There are four AT commands you will
need to set in the modem. You can set them using Wireless
Ace or a AT commands with a terminal connection (page 50). The examples shown are from
Wi
reless Ace.
*HOSTPRIVMODE=1 - Private Mo
de turned on.
*HOSTPRIVIP=[IP addr
ess] - IP address assigned to computer or other end device con-
nected directly to the modem (example, 192.168.1.8).
*HOSTPEERIP=[IP addr
ess] - IP address assigned to modem for local, not cellular, com-
munication (example, 192.168.1.9).
*HOSTNETMASK=[subnet
mask] - Subnet Mask setting (example, 255.255.255.0).