User guide

Services Configuration
Rev 2.3 Feb.12 99
Dynamic DNS
Dynamic DNS allows an AirLink device WAN IP address to be published to a
proprietary Sierra Wireless dynamic DNS service called IP Manager, or to an
alternate third party service provider.
If you have one Sierra Wireless AirLink device, or a fleet of devices, it can be
difficult to keep track of the current IP addresses, especially if the addresses are
not static but change every time the devices connect to the cellular network. If you
need to connect to a gateway, 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 Device 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 device 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, for data only being sent
out, or for data only being received after an initial request (also called Mobile
Originated). However, if you need to contact the AirLink device directly, a device
connected to the AirLink device, or a host system using your AirLink device (also
called Mobile Terminated), a dynamic IP will not 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 AirLink device is
connected and can change each time the gateway reconnects to the network.
• Static IP addresses are granted the same address every time your AirLink
device is connected and are not in use when your gateway is not connected.
Since many cellular providers, like wire-based ISPs, do not offer static IP
addresses or static address accounts (which can cost a premium as opposed to.
dynamic accounts), Sierra Wireless AirLink Solutions developed IP Manager. IP
Manager works with a Dynamic DNS server to receive notification from Sierra
Wireless AirLink devices to translate the dynamic IP address to a fully qualified
domain name. Thus, you can contact your AirLink device directly from the Internet
using a domain name.