[Serusers] Ser configuration question

Hi, I have a fixed IP assigned from comcast.net as 68.34.193.70, dns reverse resolve is pcp667462pcs.indpnd01.mo.comcast.net. On this address I'm running a freeBSD server with named. I've registered my domain as cavtech.com, and set this server as it's primary DNS. My DNS resolves cavtech.com as 68.34.193.70, as well as it's hostname of ctimain. I've added a CNAME in the DNS pointing ser.cavtech.com to ctimain. I've also added the _SIP:_UDP SRV entry to point to port 5060. I've added the following to the ser.cfg: alias="ctimain.cavtech.com" alias="cavtech.com" alias="ser.cavtech.com" I've set up MySQL and ser starts normally. My goal is to have windows messenger authenticate with my server as an additional communication server. My question deals with the www_authorize call. Do I put in the reverse dns hostname from comcast.net or do I put in "cavtech.com". Likewise when I set up WM, do I put in "cavtech.com" or "ctimain.cavtech.com" or "ser.cavtech.com" or the actual revdns hostname? I understand that the realm column in the MySQL subscriber base must match whatever host name is correct. I have an additional sipsak problem but I'll wait for the answer to this to see if that problem persists. Thanks.