Thanks Chris,
I used to have Cisco routers there, but Swisscom kept upgrading the service faster than I could buy new routers. With the Cisco very little was obscured and you could make them do almost anything. However I am very happy to live with the minor Internet Box issue, but would welcome a fix - I have a messy workaround.
Thanks for your help. I’ll take it up with Swisscom in a few weeks.
Graham