Hello Alan,
welcome to the Polycom Community.
It is always useful to include the currently used UC Software version as issues experienced may already be addressed in a newer release.
Please also include if you are using a SIP server or a LYNC server
If LYNC or Skype please provide Version details and if these are on premise of off premise
This also allows yourself and others to check against current software release notes.
The above is also stated in the "Read First"
Therefore the Polycom VoIP FAQ contains this post here:
Question: How can I find out my SIP UC Software Version or the BootROM Version of my Phone?
Resolution: Please check here
A wireshark trace may be helpful but would need to be looked at by Polycom support so please raise this via your Polycom reseller.
If the reseller is some Internet discounter and is unable or unwilling to do this please provide me with a MAC address of one of the phones and I look this up.
Please ensure to provide some feedback if this reply has helped you so other users can profit from your experience.
Best Regards
Steffen Baier
Polycom Global Services