The Admin Guide states:
The above includes SPIP331.
Therefore the parameter should be:
If the above does not work and your customer refuses to upgrade to a currently supported version I can only ask you to either try and get help here or open a PPI / Pay per incident ticket with your Polycom reseller if the phone is out of warranty.
Please ensure to provide some feedback if this reply has helped you so other users can profit from your experience.
Polycom Global Services
I didn't understand that the parameters "IP_330" would works for all models 32x/33x. I didn't pay attention!
Thank you very much for your support and attention. Congratulations by your commitment and dedication.