## 12.3 UDP Stream Objects

Note that, unlike the name suggests, there is nothing stream-like about UDP.

`asr`
  The asynchronous service routine to be called on events such as datagram arrival without outstanding `Read` call. The asr has a single argument, the event code.

`port`
  A read-only member giving the port number of this UDP Stream.

`Read` (timeout)
  Read a datagram, waiting at most timeout seconds (-1 is infinite). Return the data.

`Write` (host, port, buf)
  Send buf as a datagram to IP-address host, port port.