I live in Australia and I have a 600 series wall socket for my phone.
I want to install the US RJ-11 wall socket (which are fitted in newer
homes). Are there any diagrams on the internet showing where the wires
fit in to the standard RJ-11 wall socket?

Sure!

A basic wiring diagram for a RJ-11 jack can be found at:

T-568 and Telephone Color Codes
http://yoda.uvi.edu/InfoTech/rj45.htm

--Providing-- that Telstra uses the same wiring colors as in the U.S.
This seems to be, at least up to present, Telstra proprietary
information.

You'll also find instructions, advice and wiring diagrams from
Phone-Man. There are several Telstra entries in the Guestbook, I'm
guessing that the diagrams proved useful.

Phone-Man's Home Wiring Advice Page
http://www.homephonewiring.com/add-jack.html

Answer Strategy

Marriage to PacBell Cable Repairman, a classic case of the cobbler's
children going barefoot. I had to learn how to wire our own house's
telephone jacks.

Google Search Terms:

rj-11 "wiring diagram"


I hope this provides all you need. 

--- larre

Thank you!