Sierra Wireless 2170042 - Manual (Page 2)

Rev A Dec.08 2
Configuring your Sierra Wireless
AirLink modem for IP Manager
and DNS
If you have a fleet of Sierra Wireless AirLink modems or even
if you only have one, it can be difficult to keep track of the
current IP addresses, especially if the addresses aren’t static
but change every time the modems connect to your cellular
provider. If you need to connect to a modem, or the device
behind it, it is so much easier when you have a domain name
(car54.mydomain.com, where are you?).
Reasons to contact the modem and/or the connected
device:
• Requesting a location update from a delivery truck.
• Contacting a surveillance camera to download logs or
survey a specific area.
• An oil derek that needs to be triggered to begin pumping.
• Sending text to be displayed by a road sign.
• Updating the songs to be played on a juke box.
• Updating advertisements to be displayed in a cab.
• Remote access to a computer, a PLC, an RTU, or other
system.
• Monitoring and troubleshooting the status of the modem
itself without needing to bring it in or go out to it.
A dynamic IP address is suitable for many Internet activities
such as web browsing, looking up data on another computer
system, data only being sent out, or data only being received
after an initial request (also called Mobile Originated).
However, if you need to contact your modem directly, a device
connected to the modem, or a host system using your modem
(also called Mobile Terminated), a dynamic IP won’t give you a
reliable address to contact (since it may have changed since the
last time it was assigned).
Domain names are often only connected to static IP addresses
because of the way most domain name (DNS) servers are set‐
up. Dynamic DNS servers require notification of IP Address
changes so they can update their DNS records and link a
dynamic IP address to the correct name.
• Dynamic IP addresses are granted only when your modem
is connected and can change each time the modem recon‐
nects to the network.