When routing high speed designs, you will need to constrain your design using Skew Groups. CR-8000 Design Force has the automated Lengthening tool which makes this job easier, and faster.
Once you have created your skew groups in the Constraint Browser, you then need to tune the traces to match the lengths. The easiest way to do this is to use the automated Lengthening tool. You need to make sure you have turned on the Intelligent Router , in the bottom Status Bar. Select the skew group in the Constraint Browser, making sure the Send Selected Items Always button is on in the Constraint Browser. Then select Track, Lengthen in Design Force.