SIP INVITE Ghost/Bogus Calls - and Allow Direct IP Call settings

[michael@newcoit.com]

Hello all,

We have numerous customers who variously receive ghost/bogus calls on their Yealink phones due to SIP INVITE probing/flooding from others on the Internet.

It seems that setting "Allow IP Call" to DISABLED in the phone configuration UI under Features > General Information on a T46G will PREVENT these type of bogus / SIP invites. I've confirmed this by using an inviteflood tool.

Now that I can disable it on the web UI - how do I do this via the phone configuration files so that ALL of my phones can have this feature disabled? I cannot find this option in the user guide or looking at existing template configuration files, whether the common cfg or the phone specific cfg

Please note also that I have already tried using the option, account.x.sip_trust_ctrl=1, this option does not unfortunately prevent the bogus calls (not sure what it even does)

My questions are:

Which phone models and firmware revisions are needed for a phone to support the Allow IP Call = Disable

Looking for W52p, T21, T38, T42, T46 specifically - how to disable on these - and any differences in configuration each would require to disable this feature via cfg file.

Thank you for any assistance or insight anyone can provide.