i have the latest firmware installed on the HT812 and some of my current configuration is below
SIP Enabled (I would prefer to use SIPS)
SRTP Enabled and Enforced.
If i use SIPS the telephone rings however, i am unable to hear them and they are unable to hear me. The call hangs up after 30secs or so. If i change the settings to use TCP and SIPS the connection is sucecssful.
I have engaged the VOIP provider and they confirmed the same results, using SIPS and TLS they responded back as follows - “we found that the Grandstream was not acknowledging a 200 OK message, which caused the calls to drop”.
is this some sort of bug in the system and what methods can i do to help pin point the issue and work with the VOIP provider?