I need help setting up an Avaya softphone with the IP office. A local contractor tried but had no luck. I am getting authentication errors with working credentials.

Need External Contacts in freepbx Contact Manager made available to the phonebook in a Yealink T46s phones.

I need a Grandstream pbx installed to be interfaced with a Fosse PMS Server at a hotel. All lines and extensions are existing just need to remove the mitel pbx and replace it with the new Grandstream voip UCM6304A.