anchor.diff:  		"z9hG4bK" ++ RestOfBranch ->
   		    %% The previous hop has put a RFC3261 branch in it's Via. Use that,
   		    %% togehter with our nodename as branch.
  -		    In = lists:flatten(lists:concat([node(), "-rbranch-", RestOfBranch])),
  +		    In = lists:concat([node(), "-rbranch-", RestOfBranch]),
   		    {ok, "z9hG4bK-yxa-" ++ make_base64_md5_token(In)};
   		_ ->
   		    %% No branch, or non-RFC3261 branch
  
positive.code: 		    ToTag = sipheader:get_tag(keylist:fetch('to', Header)),
  		    CallId = keylist:fetch('call-id', Header),
  		    {CSeqNum, _} = sipheader:cseq(keylist:fetch('cseq', Header)),
  		    In = lists:flatten(lists:concat([node(), "-uri-", OrigURIstr, "-ftag-", FromTag, "-totag-", ToTag,
  						     "-callid-", CallId, "-cseqnum-", CSeqNum])),
  		    {ok, "z9hG4bK-yxa-" ++ make_base64_md5_token(In)}
  	    end;
  	_ ->
  
negative.code: %% Returns : Result of make_3261_token()
  %%--------------------------------------------------------------------
  make_base64_md5_token(In) ->
      MD5 = binary_to_list(erlang:md5(In)),
      %% remove the trailing == from the result of encode_base64()
      Out = string:strip(httpd_util:encode_base64(MD5), right, $=),
      make_3261_token(Out).
  
  %% RFC 3261 chapter 25 BNF notation of token :
  