I'm trying to figure out how to pass a filter parameter on a Services rest call. I've got a node of a specific type that I'd like to access through the Services module and rest. I'm testing with FireFox RestClient and I can get all nodes of the particular type by typing

http://localhost/drupal/gpa/node/?parameters[type]=node_type

But, I'd like to be able to get one specific instance of 'node_type' that contains a specific field value. I've taken a look at node_resource.inc, but, I can't seem to make heads or tails of what I need to use as parameters. I've tried several variations that typically return no result, or, all instances of, 'node_type'.

Is it possible to filter the returned results, or, is my approach incorrect?