C → S → C {type:'transfer', from:…, to:…, transfer_to:…, transferred_by:…}

transfer – transfer call to other recipient. Make remote client call somebody else.
When sent during a call it makes remote client call address supplied in transfer_to instead and after that call is established terminate current call.

arguments:

• from - address of client initiating call transfer
• to - address of client who should switch call
• transfer_to - address of client who should be called instead
• transferred_by - address of client initiating call transfer

transfer_result