anchor.diff:      {CSeq, Call1} = nksip_call_uac_dialog:new_local_seq(Req, Call),
       Req1 = Req#sipmsg{vias=Vias, cseq=CSeq},
       % Contact would be already generated
  -    Opts1 = nksip_lib:delete(Opts, make_contact),
  +    Opts1 = Opts -- [make_contact],
       {NewUAC, Call2} = new_uac(Req1, Opts1, From, Call1),
       NewUAC1 = NewUAC#trans{iter=Iter+1},
       send(NewUAC1, update(NewUAC1, Call2)).
  
positive.code:         id = Id,
          status = Status,
          opts = Opts,
          method = Method, 
          iter = Iter,
          from = From
      } = UAC,
  
negative.code:     Call2 = case lists:member(no_dialog, Opts) of
          true -> Call1;
          false when ToTag == <<>> -> Call1;
          false -> nksip_call_uac_dialog:request(Req, IsProxy, Call1)
      end,
      Call3 = nksip_call_uac_reply:reply({req, Req}, UAC1, Call2),
      sent_update(Req, UAC1, Call3).
  