WAS multiple virtual hosts question

In our attempt to separate normal Portal traffic from other traffic, we have set up 2 application clusters and 2 virtual hosts (in addition to default_host) in WebSphere.  One of the clusters is intended for normal Portal users, and the other is intended to handle data calls from MSCM.  I have found that all traffic is being handled by one of the clusters, and the other one is idle.  I have been doing some research and I think the problem is in my assignment of ports to the different virtual hosts, but I have not yet found good documentation on how this should work.  I have several questions.  Among them: 1) when you create one or more virtual hosts, do you use default_host for any of the Lawson applications (Security/BPM/IOS), or do you use only the new virtual hosts?  2) Are all of your port assignments unique between virtual hosts? 3) Wwhen assigning ports to virtual hosts, do you use same port numbers but different host names corresponding to different URLs?

Please feel free to contact me at gary.padgett@moffitt.org or call me at 813-745-1781.  Thanks