Scope:The function of this checklist is to test all scenarios in which there may be an interoperability in service using Asterisk 2.3 - 4.0 ,Cisco IAD trunk and extensions, Obi ATA and 3CX.Requirements:Access to EquipmentAccess to Extension for testingPhysical and Logical Network LayoutMake, Model and Software Version of Equipment TestingInteroperability Testing ChecklistExtension remains registered for more than 5 minTwo Way AudioDTMF Picking up calls, placed on hold or in parking lotTransferring calls to other extensionsAccess to voicemail Being on a call for more than 30 minCall not ending when Extension is hung-up (Desk Ext & Mobile Ext)  Call Forwarding Show different outbound caller IDCNAM shows correctly Picking up other extensions' calls from another extension