Payload:    req,
		DeadlineMS: uint32(m.deadline.Milliseconds()),
	}
	if m.subroute != nil {
		msg.Flags |= FlagSubroute
	}
	ch := make(chan Response, 1)
	m.respMu.Lock()
	if m.closed {
		m.respMu.Unlock()
		return nil, ErrDisconnected
	}
	m.respWait = ch
	m.respMu.Unlock()
	ctx := m.ctx

	// Add deadline if none.
	if msg.DeadlineMS == 0 {

		err = msgp.WrapError(err, "MuxID")
		return
	}
	z.Seq, err = dc.ReadUint32()
	if err != nil {
		err = msgp.WrapError(err, "Seq")
		return
	}
	z.DeadlineMS, err = dc.ReadUint32()
	if err != nil {
		err = msgp.WrapError(err, "DeadlineMS")
		return
	}
	{
		var zb0002 uint8
		zb0002, err = dc.ReadUint8()
		if err != nil {
			err = msgp.WrapError(err, "Handler")
			return
		}

			b, err = handler(m.Payload)
			if debugPrint {
				fmt.Println(c.Local, "Handler returned payload:", bytesOrLength(b), "err:", err)
			}
		}()

		if m.DeadlineMS > 0 && time.Since(start).Milliseconds()+c.addDeadline.Milliseconds() > int64(m.DeadlineMS) {
			if debugReqs {
				fmt.Println(m.MuxID, c.StringReverse(), "DEADLINE EXCEEDED")
			}
			// No need to return result
			PutByteBuffer(b)
			return
		}