I've been away from here for a while, and can't find what I remember as an old discussion of the topic.
Should the UserAgentPort, (formally the X_UserAgentPort field under Voice Services > SPx Services) be unique or can it be duplicated on multiple OBi devices sitting behind one router. In this case a SOHO router, and multiple Obi 202s, plus one Obi110
Note that when one Obi device is configured via the ObiTalk portal, the portal knows to increment the port number, such as 5080, 5081, ...5083 for an Obi202 with all four SPs services configured.
However, when multiple OBi devices are located behind the same router, they all start at the same port no, 5080, 5081, ...5083 and you get two (or three or four) obi devices having the same user agent port.
I seem to recall some discussion on here, that I can no longer find, giving some reasons why you should not duplicate the port 3s across multiple devices, ... it had something to do with the router (or some routers) not cleanly being able to keep track which sip client (NAT-ed host) a SIP packet was destined for.