D7 allows command line access via telnet as well.
You have to figure out all command lines supported by D7 via help command by yourself.

Thanks for replying.
I had already tried that before posting.
Unless I'm missing something, the only options I'm given are: adsl, igmp, wan, wlctl, iptv, lan and dev
None of which have options to show devices connected or registered or the last lease times.

Any hints tips gratefully received !