parsing variable length XML?

I'm new to Ruby and need to write some code to parse a variable length
XML structure like the one below. In the below case, the <port> time
can occur a variable number of times. I want to store each one of
these port numbers into a separate database record.

Also, is there anyway for Rails to automatically insert these into a
relational set of models. For instance, the Address record would
contain the 'host' and then a many to many relationship to a bunch of
port numbers. Are there any features or libraries to make this mapping
easier when parsing?

Thanks
Chirag

<address>
  <host>example.org</host>
  <port>1234</port>
  <port> 5678</port>
  ...
  <port> 6789</port>
</address>