Polycom Firmware Upgrade / Downgrade question

[Peter Krautle]

I've got two VVX phones at Polycom firmware 5.9.5 testing firmware upgrades and downgrades for customer migrations - they are registered to 20.08, 20.04. and 16.08 systems. On all three systems, the VVX phones go into a constant reboot loop when downgrading to 5.5.2 firmware (for example), or upgrading to 5.9.6. I've tried factory resetting the phones, formatting the file system, looking at phone logs, etc and am stumped. The phones stop rebooting when 5.9.5 firmware is loaded onto the phones. Has anyone else experienced this - I must be missing something obvious. Peter

[Matt Keys]

A reboot loop usually means the firmware you're attempting to load is not compatible with the model. Check the Polycom matrix and release notes for the version ..

Soundpoint IP series: https://downloads.polycom.com/voice/voip/sip_sw_releases_matrix.html

VVX series: https://downloads.polycom.com/voice/voip/uc_sw_releases_matrix.html

[Peter Krautle]

Thanks Matt for the response, but I'm getting closer to the root cause - this thread indicates that there is a Polycom firmware issue in 5.8+ releases https://community.polycom.com/t5/VoIP-SIP-Phones/VVX-Phone-in-reboot-loop-after-firmware/td-p/102557. One user suggested that downgrading the port speeds on Cisco switches from Gige to 100BT corrected the bootp look. On our lab 35xx switch, I played around with the speed and duplex settings and was unable to correct the Bootp loop issue. Today, I built a lab system using 20.08 with Pfsense 2.5.2. When the phones get their networking information from Pfsense, they go into  boot loop with 5.9.5 firmware - this doesn't happen when the Sipxcom DHCP server is used. I'm going to do a quick compare of the DHCP responses between Sipxcom and Pfsense servers to see if anything jumps out.