VoIP: SIP-over-TLS and sRTP: PortSIP Softphone

Last tested version

9.1.16
retested in May 2020 with 9.2.7

Configuration

SIP-URI User: UserName
SIP-URI Host: Domain
SIP-over-TLS: Advanced → Transport: TLS
… TLS Cert Management: Verify TLS Cert
since 9.2: TLS does not work for me at all: ‘no transport left to try’
SDES-sRTP: Sign In → Settings → Preferences → SRTP: Prefer
which is RTP/SAVP

Software Bugs

SHA-2 Digest: does not pick MD5, continues without header Authorization, therefore is not able to register; therefore incompatible with Linphone
AES-256 sRTP: accepted although not supported; therefore no audio

Security

Bugs: SIP-over-TLS without authentication
because ‘Verify TLS Cert’ failed for me

back to the other (soft) phones.