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>