Rev. 6 May.13
Services Configuration
Dynamic DNS
Dynamic DNS allows a AirLink Device WAN IP address to be published to a proprietary Sierra Wireless dynamic DNS service called IP Manager.
If you have a fleet of Sierra Wireless AirLink devices or even if you only have one, 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:
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Requesting a location update from a delivery truck
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Contacting a surveillance camera to download logs or survey a specific area
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An oil derek that needs to be triggered to begin pumping
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Sending text to be displayed by a road sign
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Updating the songs to be played on a juke box
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Updating advertisements to be displayed in a cab
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Remote access to a computer, a PLC, an RTU, or other system
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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: 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). If you need to contact the AirLink device directly, however, 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.
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Dynamic IP addresses are granted only when your AirLink device is connected and can change each time the gateway reconnects to the network.
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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 cost a premium vs. dynamic accounts,
Sierra Wireless AirLink Solutions developed IP Manager to work 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.
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ALEOS User Guide
Figure 8-4: ACEmanager: Services > Dynamic DNS
Field
Device Name
Description
The name you want for the device. There are some restrictions listed below for the device name.
Domain
The domain name to be used by the device. This is the domain name of the server configured for *IPMANAGER1
IP Manager Server 1
(IP Address)/IP
Manager Server 2 (IP
Address)
The IP address or domain name of the dynamic DNS server which is running IP Manager.
IP Manager Server
Update1/IP Manager
Server Update 2
IP Manager Server 1
Key/IP Manager
Server 2 Key
How often, in minutes, you want the address sent to IP Manager. If this is set to zero, the device will only send an update if the IP address changes (example, if your AirLink device is reset or is assigned a different IP address).
User defined password key which is used instead of AirLink secret key when using an IP
Manager server other than the one provided by Sierra Wireless.
Tip:
Some PPPoE connections can use a Service Name to differentiate PPPoE devices.
Use the device name to set a Station Name for the PPPoE connection.
Understanding Domain Names
A domain name is a name of a server or device on the Internet which is associated with an IP address. Similar to how the street address of your house is one way to contact you and your phone number is another, both the IP address and the domain name can be used to contact a server or device on the Internet.
While contacting you at your house address or with your phone number employ different methods, using a domain name instead of the IP address actually uses the same method, just a word based name is commonly easier to remember for most people than a string of numbers.
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Services Configuration
Understanding the parts of a domain name can help to understand how IP
Manager works and what you need to be able to configure the device. A fully qualified domain name (FQDN) generally has several parts.
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Top Level Domain (TLD): The TLD is the ending suffix for a domain name
(.com, .net, .org, etc.)
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Country Code Top Level Domain (ccTLD): This suffix is often used after the
TLD for most countries except the US (.ca, .uk, .au, etc.)
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Domain name: This is the name registered with ICANN (Internet Corporation for Assigned Names and Numbers) or the registry for a the country of the ccTLD (i.e. if a domain is part of the .ca TLD, it would be registered with the
Canadian domain registry). It is necessary to have a name registered before it can be used.
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Sub-domain or server name: A domain name can have many sub-domain or server names associated with it. Sub-domains need to be registered with the domain, but do not need to be registered with ICANN or any other registry. It is the responsibility of a domain to keep track of its own subs.
car54.mydomain.com
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.com is the TLD
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mydomain is the domain (usually noted as mydomain.com since the domain is specific to the TLD)
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car54 is the subdomain or server name associated with the device, computer, or device registered with mydomain.com
car54.mydomain.com.ca
This would be the same as above, but with the addition of the country code. In this example, the country code (.ca) is for Canada.
Tip:
A URL (Universal Resource Locator) is different from a domain name in that it also indicates information on the protocol used by a web browser to contact that address, such as
http://www.sierrawireless.com
. www.sierrawireless.com is a fully qualified
domain name, but the http://, the protocol identifier, is what makes the whole thing a URL.
Dynamic Names
When an IP address is not expected to change, the DNS server can indicate to all queries that the address can be cached and not looked up for a long period of time. Dynamic DNS servers, conversely, have a short caching period for the domain information to prevent other Internet sites or queries from using the old information. Since the IP address of a device with a dynamic account can change frequently, if the old information was used (such as with a DNS server which indicates the address can be cached for a long period of time) when the IP address changed, the domain would no longer point to the new and correct IP address of the device.
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