Not sure we have any carriers in AU that support TLS yet so my answer is NO
who is the trunk provider ? is there an MBG involved?
there is a kms article for peerless HO 3882 that has some references (notes below)
MIVB System Options
Set Voice Encryption Enabled and Voice/Video SRTP Encryption Enabled to YES
MIVB NWE for Carrier
set transport to TLS port 5061
External SIP proxy to TLS port 5061
Sip registrar to TLS 5061
MIVB NWE for MBg
set Outbound proxy transport type to TLS port 5062
MIVB SIP Peer
set AVP only to NO
in ARS route set to SIP trunk But Route type to PSTN via DPNSS ? this might just be a peerless setting
IN MBG SIp proxy
system /trust store
upload the carrier certificate
SIP trunk config
set transport to TLS
Outgoing TLS trust provider to cert imported above
Remote trunk Endpoint Port 5061
trunk Side rtp Security Inbound to SRTP or RTP Inbound SRTP only
Outbound to SRTP only outbound SRTP
If I never did anything I'd never done before , I'd never do anything.....