The error I faced:
ERROR:core:tcp_init_listener: bind(32, 0x7f72fe4879ac, 16) on 11.22.33.44:443 : Permission denied ERROR:core:trans_init_all_listeners: failed to init listener [11.22.33.44], proto wss ERROR:core:main: failed to init all SIP listeners, aborting
The service could not start neither manually (opensips -f /path/to/cfg) nor via SystemD. The checking (opensips -C -f /path/to/cfg) of config file showed no errors.
Use ‘setcap’ command.
Example for OpenSIPS running as opensips:opensips.
How I fixed:
setcap CAP_NET_BIND_SERVICE=+eip /usr/sbin/opensips