After upgrading from firmware 4.0.1 to firmware 4.0.2 I always hear 2 different tones (one loud and one quiet dial tone right after) whenever I dial a PSTN number from my Polycom phone.
Did anything change between 4.0.1 and 4.0.2 related to call progress dial tone?
welcome to the Polycom Community.
This sounds like something I was able to find internally and seems to be applicable to the UCS 4.0.2 Rev B Version.
A wireshark trace would show if you are receiving a INVITE with a 180 first (causing the phone to generate it's own ringback) and then a 183 with the Networks Audio as SDP.
I suggest you check this or work with your reseller to bring this to the attention of Polycom Support in order to be able to track this properly and verify that the software is causing this.
Please ensure to provide some feedback if this reply has helped you so other users can profit from your experience.
Polycom Global Services
Thank you for the reply.
After a test using wireshark, I can confirm I receive both a SIP 183 and a SIP 180.
I would expect the Polycom phone to ignore the SIP 180 if it receives a SIP 183, which is probably the case when using firmware 4.0.1 instead of 4.0.2 firmware.
as mentioned above please bring this to the attention of Polycom Support in order to be able to track this properly and verify that the software is causing this.