Thanks to one our Customer John, who took time to prepare this document for us. Lot of people used to struggle in configuring their 3cx VoIP system with DIDForSale. John from www.it-solutionsusa.com has prepared this step by step instructions on How to Configure 3cx SIP voip system.
Click on the link below.
How to Configure 3CX with DIDForSale

Thank you John,
www.it-solutionsusa.com