Merging a local IP Office conference with a conference on Avaya Aura® Conferencing is not supported on an IP Office phone.
A SIP trunk call connected to an Avaya Aura® Conferencing network cannot be added to an IP Office conference. The calls will not merge if you try to create a local IP Office ad-hoc conference.
A SIP trunk call added to a local IP Office conference cannot process conferencing data from the Avaya Aura® Conferencing network.