iPOD Accessory Protocol 2 File Transfer Session implementation in iOS application

iAP2 supports simultaneous file transfer session(maximum 128, with FileTransferIdentifier ranging from 0-127). I have searched everywhere and couldn't locate any documentation or reference on how to implement this feature from the iOS application perspective. Currently my application uses External Accessory Framework to open session and using the inputStream/outputStream provided by EASession for the file transfer. But I want to take advantage of the filetransfersession other than the External Accessory Session for an out of band file transfer. All the information, knowledge and experience are welcome on this topic. Basically looking forward to the API's provided by iOS which can be used to achieve the objective.