If I see it right you made two postings about Polycom systems.
Did they work before you upgraded to TMS 12.6.2?
If yes, and you have a service contract I would consider opening a case (but please post the answer :-)
There are two things, on the port 24 error I would check if the network connection is ok, so the
service is activated on the polycom endpoint and the firewall is allowing connections from the TMS to the EP.
Regarding the other problem, I remember having read somewhere that older TMS versions relay on
a MSXML version which newer windows systems / patchlevels dont support and that there was a fix
with TMS13.1.
So if you do not get an better answer, escalate these case as a TAC case and inform us how you solved it!