anchor.diff:  | byte at offset 1 | MCS8 | MCS7| MCS6 | MCS5 | MCS4| MCS3 | MCS2 | MCS1
   |===
           
  -The content of this attribute is not used by OsmoBTS, but
  +This attribute is not used by OsmoBTS, but
   simply passed to OsmoPCU connected to the PCU socket.
   
   
  
positive.code: The value part of the GPRS Routing Area code consists of a single octet
  encoding the GPRS Routing Area Code.
  
  The content of this attribute is not used by OsmoBTS, but
  simply passed to OsmoPCU connected to the PCU socket.
  
  
  
negative.code: in network byte order, encoding the GPRS NSVCI as specified in 3GPP TS
  08.16.
  
  This attribute is not used by OsmoBTS, but
  simply passed to OsmoPCU connected to the PCU socket.
  
  
  