Meter attributes has a dependency on internet connection as they need to be updated in real-time. For example consider a license with meter attribute named channels with value 10 and allowed activation value 5.
Now suppose first machine (activation) consumes 5 channels, then only 5 channels should be available for the remaining 4 machines and this must be updated on the server in realtime, to prevent other machines from using more than 5 (remaining) channels.
To implement your use case, you should use on-premise floating licenses. That lets you implement meter attributes in an offline environment.