Thanks! Unfortunatelly, Telnet was deployed using WL's tool, not MSP. To write the plugin I need to know how to get telnet's actual version. Is it inside a file? Is there a command line argument (i.e, -v as usual) to get it programmaticaly? I guess I will raise this WL-specific question on the right forum (if any).

MSP can display the telnet package as an attribute for each device so if you had deployed Telnet using MSP you could see what version was on each device that way. Bear in mind it only reports the package version number and not the actual version of the Wavelink client, these are not necessariliy the same thing. For instance when you build the apf for the telnet client you can give it any version number you want but of course you would want to make it the same number as for the wavelink client itself contained in the package. The proper solution for you is a custom plug-in that queries the device registry for a specific key (you can make this anything you want) and makes that value an attribute in MSP. I know that this is something that the MSP BU are working on. I've used the Wavelink MSP plug-in but it doesnt appear to contain the version attribute that you want. The plug in development kit is available so it might be possible to create your own.