Providing Asterisk configuration is tricky, since it highly depends on provider/hardware/country. I tried to provide as much generic information as possible, with lots of pointers to the official Asterisk wiki. At the end I provided examples for my provider, taken from a previous forum post.
Maybe it's better to split out provider-specific configs into separate pages - what do you think?
Stefan Koch already wrote an article about chan_lantiq which I link to in my article.