anchor.diff:  
         // compute delay
         if (ack_rcvd) begin
  -         let temp = outstandingInitRequest.first;
  +         let temp = ackTimestampFifo.first;
            delay <= (c_local - temp - (rxtx_delay << 1) - 1) >> 1;
            if(verbose) $display("%d: %d update delay=%d, %d, %d", cycle, id, c_local, temp, (c_local-temp-(rxtx_delay<<1)-1)>>1);
  -         outstandingInitRequest.deq;
  +         ackTimestampFifo.deq;
         end
      endrule
   
  
positive.code:       if (mux_sel && tx_mux_sel == init_type) begin
           encodeOut = {c_local+1, parity, init_type, block_type};
           if(verbose) $display("%d: %d, Enqueued outgoing init request %d", cycle, id, c_local+1);
           outstandingInitRequest.enq(c_local+1);
        end
        else if (mux_sel && tx_mux_sel == ack_type) begin
           if(verbose) $display("%d: %d, Enqueued outgoing ack %d", cycle, id, c_local+1);
  
negative.code:       end
  
        if (ack_rcvd) begin
           // silently ignore additional ack messages.
        end
     endrule
  
  