Understanding TCP and UDP Ports on the Wireless Vehicle Adapter

When using the Digi Wireless Vehicle Adapter (WVA), there are several options for gathering vehicle telematics data from the unit.  Two of the most popular are:
  • Interact directly with the WVA through its web services API
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  • Leverage open source Python programming onboard the WVA to gather telematics and forward them to hosted platforms such as Digi Remote Manager
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Digi Remote Manager simplifies use of the WVA due to the availability of sample Python code from Digi:
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When using the WVA, there are a few points to understand about the following network ports:
  • TCP port 3199
    • Used to provide TLS (SSL) encrypted transmission via Digi’s Easy Device Protocol (EDP)
  • UDP port 53
    • Used for domain name resolution via DNS
  • UDP port 123
    • Used for time synchronization via Network Time Protocol (NTP)
If using the WVA with Digi Remote Manager, then access to the platform must be allowed via TCP port 3199.  This can be achieved through the following approaches:
  • Firewall rule allowing secure access to the IP address of Digi Remote Manager (https://my.devicecloud.com) on port 3199
  • VPN connection between the customer network and Digi Remote Manager
  • Web proxy such as Squid Proxy - http://www.squid-cache.org - to allow the URL and port 3199
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As stated earlier, port 3199 is required for communication between the WVA and Digi Remote Manager.  Even if you are not using Remote Manager to receive data directly from the WVA, the platform still provides major benefits by facilitating easy configuration and firmware updates for WVA units in field service  This helps maintain hardware reliability and security.

UDP port 53 is used for DNS look-ups of web addresses like https://my.devicecloud.com – the main URL for Digi Remote Manager.  While it is possible to avoid use of UDP port 53 by applying an IP address pointing directly to the Remote Manager platform, Digi does not guarantee that the platform’s address will always remain constant.  DNS helps reduce communication risk by allowing the WVA to locate Remote Manager, even if its IP address happens to change.

Finally, UDP port 123 is used for network time synchronization via NTP.  This can be an easy way to ensure that the timestamps for data collected by the WVA are extremely consistent.  However, it is also possible to set the WVA’s time via its built-in web services API:
http://ftp1.digi.com/support/documentation/html/90001430/index.html

Since most customers develop mobile applications to handle certain interactive tasks with the WVA, it is possible to allow the application to set or synchronize time on the WVA.  So if there is a desire to avoid use of UDP port 123, then this can be achieved using the above approach.

 
Last updated: Aug 08, 2017

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