Did you know that the WeOS DHCP server can save money in train refurbishment projects?

Refurbishment projects for on board train networks are often very cost sensitive, which is limiting the possibilities of the network design. In order to save money, much of the management are often centralised to one single switch so the rest of the network can be built with less costly unmanaged switches. However, there are base functions that always need to work regardless of budget, and Westermo has solutions that make it possible to combine cost efficiency and reliability in this type of projects.

The DHCP server is a good example of one of those base functions that just have to work. However, when centralising old equipment into one point, Option-82 (port based distribution of IP-addresses) information might not be sufficient to assign the correct IP-address to the right end-device. The problem is that the unmanaged switches connect several end-devices into only one port of the DHCP server switch, so this will require something else to identify each device uniquely. DHCP Option-61 (Client ID distribution of IP-addresses) provides a solution to this problem. Complex issues where the same device ID is presented on different ports. For example, door controllers on opposite sides of the carriage are connected to the DHCP server switch via unmanaged switches connected to different ports on the DHCP server switch. The door controllers will have the same ID but it is imperative we know which controller is on which side and the position within the carriage or the wrong door will be opened when the train arrive at a station. WeOS can resolve the issue by using a combination of Option 82 and Option 61 to work out the correct address to forward to the door controller using the Client ID (Option 61 and the port (Option 82) the request for an IP address is received.