There is no norm I'm afraid. The stats vary depending on the distance from you to the exchange (0 - 63dB), and that mainly determines the sync rate (0-24MBs) and SNR margin (0-15dB).

Friend returned from holiday an I've just been round. We've fitted 3 new single secondary sockets - garage, office and lounge. We've renewed the cable from master socket to garage socket which was also epositiond for easier access. Cabl length appeox 3 metres.

With Office connected (10m estimated cable length) to master, garage connected (3m) to master, external bell plugged into garage secondary, downlooad speed appox 4Mbps. Connect terminated or untermintated lounge cable (30m) to garage secondary the download speeds drops to 2.7 Mbps (!?!). Renove connections from garage secondary, back to 4 Mbps (!?)

Did you connect the ring wires?

An i-plate was purchased and fitted but made no difference. However, since all new sockets etc installed this has not been refitted. I'll get my friend to do that.

Only thing not changed has been the master socket. Wondering whether aging components might have an effect (straw clucthing now). Any views ?