Creating a software with Usability in mind is one part of the story. Maintaining a software is another part; transforming the needs of the users is challaging even for educated Computer Scientists. Another problem for Computer Scientists is to envolve especially when the derived projects are not first-grade software. Blink is a front end for PJSIP. Blink uses Python to access PJSIP. Blink uses the QT Framework to interact with the user. However, Blink is based not on Python 3 but on Python 2. However, Blink is based not on the current PJSIP 2.10 but on 2.4.5-svn, heavily patched. Although still receiving updates, the project very much ceased in the year 2016 already.
3.2.1 in Ubuntu 18.04 LTS (Change Log)
Ubuntu 20.04 LTS does not work because modules like python-twisted are missing; instead use an unofficial Flatpak
| Trust Anchors: | Menu → Blink → Preferences → (tab) Advanced → (TLS settings) Certificate Authority: /etc/ssl/certs/ca-certificates.crt |
| SIP-URI: | Menu → Blink → Accounts → Add account→ Add an existing → SIP address (user@host) |
| SIP-over-TLS: | enabled on default, thanks to DNS-NAPTR Menu → Blink → Preferences → (tab) Advanced → (SIP and RTP) Transports: Enable TLS |
| SDES-sRTP: | Menu → Blink → Preferences → (tab) Accounts → Media → (RTP Options) Encryption: SDES optional |
| SHA-2 Digest: | does not pick MD5, continues without header Authorization, therefore is not able to register; therefore incompatible with Linphone |
| Bugs: | SIP-over-TLS without authentication (option ‘verify_server’ does not work for hostnames but just for IP addresses; ticket 7), padlock icon even without SIP-over-TLS, and padlock icon (blue) even without sRTP |