anchor.diff:  oe_flow_tw(Key, Priority, InPort, OutPort, ChannelNumber) ->
       Version = version(Key),
       Matches = [{in_port, <<InPort:32>>}],
  -    Actions = [{set_field, och_sigid, ?OCH_SIGID(ChannelNumber)},
  +    Actions = [{set_field, och_sigid, ?FIXED_OCH_SIGID(ChannelNumber)},
                  {output, OutPort, no_buffer}],
       Instructions = [{apply_actions, Actions}],
       Opts = [{table_id,0}, {priority, Priority},
  
positive.code:     Version = version(Key),
      Matches = [{in_port, <<InPort:32>>},
                 {och_sigtype, ?OCH_SIGTYPE},
                 {och_sigid, ?OCH_SIGID(InChannelNumber)}],
      Actions = [{output, OutPort, no_buffer}],
      Instructions = [{apply_actions, Actions}],
      Opts = [{table_id,0}, {priority, Priority},
  
negative.code: -type switch_key() :: integer().
  
  -define(OCH_SIGTYPE, <<10>>).
  -define(FIXED_OCH_SIGID(ChannelNumber), ?OCH_SIGID(1, 2, ChannelNumber, 1)).
  -define(OCH_SIGID(GridType, ChannelSpacing, ChannelNumber, SpectralWidth),
          <<GridType:8, ChannelSpacing:8, ChannelNumber:16, SpectralWidth:16>>).
  
  %% @hidden
  %% activate tracing for debugging
  