What is the preferable way of appending/combining ArrayBuffers?

I'm receiving and parsing network packets with a variety of data structures. Incoming messages are read into ArrayBuffers. If a partial packet arrives I need to store it and wait for the next message before re-attempting to parse it.

Currently I'm doing something like this:

function appendBuffer( buffer1, buffer2 ) {

  var tmp = new Uint8Array( buffer1.byteLength + buffer2.byteLength );

  tmp.set( new Uint8Array( buffer1 ), 0 );

  tmp.set( new Uint8Array( buffer2 ), buffer1.byteLength );

  return tmp.buffer;

}

Obviously you can't get around having to create a new buffer as ArrayBuffers are of a fixed length, but is it necessary to initialize typed arrays? Upon arrival I just want is to be able to treat the buffers as buffers; types and structures are of no concern.