Hortoristic,
Here is my limited understanding of what is going on. The SIP scanners are testing millions of IP addresses and at each address they test port 5060. The nuisance calls are not coming in via your service providers, but direct to your ip address/port, so it does not matter what service provider is say on sp1. In the Obi UserAgentPort for sp1 is 5060 by default. This is the one to change to some random port as posted above. I think some scanners may also look at 5061 and 5070, as I got caught using them. Using non-default ports and the above string has worked for me.
I don't have an Obi202, so I'm curious about the Call History. You says yours shows: "From '1' SP1(1)" – does this indicate a Caller ID of "1"? If so, then the |x| rule in the string will stop it and any other single-digit Caller ID.
Blocked calls will not show up in Call History, as effectively the calls are not getting into the Obi.