UDP, Multicast and IGMP?

Hi all, I posted a few days ago to ask about UDP and Multicasting. After reading a little more thoroughly, I think what I am looking for is IGMP (Internet Group Managment Protocol). Does REBOL support this in any way? I'd have no problem using the defined "broadcast" addresses, but I'm unsure how I would generate a packet to indicate a desire to join a multicast group, or leave one... I've been looking over the built-in protocols and a few source files of user created protocols... Unfortunately they aren't too well documented, so I'm not sure where I would start if I was to try and create an IGMP protocol stack in REBOL - if it's even possible. Certain portions are certainly possible - IGMP centers around various multicast address, and it'd be easy to send packets to them in REBOL. However, the question I have is how I could format low-level packets to issue IGMP commands to join, leave, or report on various group memberships. Is it possible to access the data stream of an open port within rebol in a "raw" fashion? If so, I think I could manage the basics of issuing membership query, membership report, and leave report messages. Any experts out there in crafting REBOL protocols, please let me know if I'm wayyy off track. - Porter Woodward