FreePBX / Trixbox
I am starting off by trying to get voip.co.uk working, then I want to
go onto voiptalk.
I am using a softphone (x-lite) as my test extension as I currently
only have one ATA and that is in service.
I have suceeded in getting outgoing calls to work. However I am having
no luck at all with incoming calls.
I Googled and found some settings but still no luck.

I have set the' Inbound Route' to accept any DID and the 'Core' to
route directly to my extension (softphone).

The trunk has INCOMING settings:-

User Context 123456

Under 'User Details' :-

authuser=123456
canreinvite=no
context=from-pstn
fromdomain=proxy.voip.co.uk
fromuser=123456
host=proxy.voip.co.uk
insecure=very
secret==xxxxxxxx
type=peer
username=123456

Where 123456 represents my userID and xxxxxxxx my password.

Register String
123456:xxxxxxxx@registrar.voip.co.uk/123456

( I have also tried @proxy.voip.co.uk as suggested on one of
voip.co.uk technical pages.)

Any ideas about what I am doing wrong or need to add?

Further, do I need to do anything in regard to my dynamic IP?

Remove 'no_spam_' from email address.