Dear All I have encountered the issue called "Assert @ 1410 HAL_DDM_C55X FATAL Exception_27" on my few IP Phones yesterday.
The model of Mitel IP Phone we are using is 5330/5330e. We are using 2 different VLAN, only the VLAN for guest is having an issue. after resart PABX is working fine. But this is a second-day the problem occurred. Please help me to fix this issue.
Assert errors on 5330 phones usually fall into two categories... The firmware is incorrect for the system, meaning it does not match the firmware supplied with the system. We run into this occasionally when the TFTP port is blocked between VLAN's, the phones are manually configured and no TFTP address is specified (ie. not just placed in Teleworker mode), or the DHCP options are incorrect. The other likely cause is the phone itself is failing and the NVRAM chip that hold the firmware is corrupt.
That said, the fact you rebooted the phone system and it worked fine is odd... Assert errors are typically processing errors within the device itself.
Phones should not be on a "guest" VLAN... A true "guest" VLAN should have no connectivity to the data or voice network, just to the Internet. One thing many "guest" VLAN's have is client isolation, meaning clients cannot talk to other clients, and this could cause issues with the phones as well as although all control signalling goes through the controller, media (RTP) passes directly from phone to phone
