I have an outside workshop/office that I ran some cat5 cable to some
years ago. This link is now playing up a bit - intermittent - and I have
been looking at replacing the cable, which I know has become a bit
fragile in places - a bit of a tedious job.

I understand that such a link can be achieved with suitable adaptors
through the ring main. Has anyone here done this who can offer
advice/guidance as the best and most economical way to go about it?