Playback streaming audio with AVAudioengine (iOS)

I want to stream audio on iOS and use for that use-case the AVAudioEngine. So, currently I'm not really sure, what is the best solution for my problem.

I get the RTP data from the network and want playback this audio data with AVAudioEngine. I use the iOS Network.Framework to receive the network data. Then first I decode my voice data and want to playback it, now.

Here is my receive code:

connection.receiveMessage { (data, context, isComplete, error) in
  if isComplete {

  // decode the raw network data with Audio codec G711
  let decodedData = AudioDecoder.decode(enc: data, frames: 160)

  // create PCMBuffer for audio data for playback
  let format = AVAudioFormat(settings: [AVFormatIDKey: NSNumber(value: kAudioFormatALaw), AVSampleRateKey: 8000, AVNumberOfChannelsKey: 1])
  // let format = AVAudioFormat(standardFormatWithSampleRate: 8000, channels: 1)
  let buffer = AVAudioPCMBuffer(pcmFormat: format!, frameCapacity: 160)!
  buffer.frameLength = buffer.frameCapacity

  // TODO: now I have to copy the decodedData --> buffer (AVAudioPCMBuffer)

  if error == nil {
  // recall receive() for next message
  self.receive(on: connection)
  }
}

?How I have to copy my decoded data into the AVAudioPCMBuffer? Currently, my AVAudioPCMBuffer is created, but not contain any audio data.

Background information: My generell approach would be to cash here in the above code (at ToDo-Line) the PCMBuffer in a collection and playback this collection by the AVAudioEngine (in a background thread).

My decoded linear data is cashed in an array from type Int16. So the var decodedData is from type [Int16], maybe there is a possibility to consume this data directly? The function scheduleBuffer allows only AVAudioPCMBuffer as input.