hi
per my experience, we consider to sepcify one domain to be used as the default routing domain; for OCS Server support SIP domain number? i think it's not important;
if there are lots of SIP domain in your vritual/production enviornment, i recommend do as the following steps in order to logon automaitcally OCS pool?
(1)prepare domain in non-default routing domain?
(2) add A record for OCS pool, then create srv record;
(3) when you apply certificate for OCS pool, please make sure "subject alternative name" of certificate include each SIP domain name and OCS pool FQDN name?
if there is anything unclear, please free time tell me, let us talk about;thanks;
best regards
-Jack