Hi Paul,
there is also a webinar and a training material based on version 8.0 for "Standard ERP - Communication Centre", where you can find some info about Asterisk and setup in the Telephony module.
You need to go to: Education >> Training Materials for Standard ERP >> follow the link posted there >> Standard ERP - Communication Centre >> and at the end you will see buttons to watch the webinar or to download the material in PDF (please remember you have to be logged in to see those buttons).
If any problems please let me know.
Kind Regards,
Diana Kllobukowska