Plantronics + Polycom.
Now together as
Just a friendly notification if you upgrade RPRM to the 10.5 (or install from fresh):
This means that, until 10.4 you could connect the phones to RPRM (you just needed to disable the TLS security 'Common Name Validation').
From 10.5, the phones need to trust the CA that issued the RPRM certificate.