After a year of development, a new stable branch of the open communication platform Asterisk 21 was released, used to deploy software PBXs, voice communication systems, VoIP gateways, organizing IVR systems (voice menu), voice mail, conference calls and call centers. The source texts of the project are available under the GPLv2 license.
Asterisk 21 is classified as a regular support release, with updates rolling out over a two-year period. Support for the LTS branch of Asterisk 20 will last until October 2027, and Asterisk 18 until October 2025. Support for the 17.x LTS branch has been discontinued. LTS releases focus on stability and performance optimization, while regular releases focus on adding functionality.
Among the changes in Asterisk 21:
- The capabilities of the res_pjsip_pubsub module have been expanded, adding additional capabilities to the PJSIP SIP stack for distributed exchange of device status data via the Jabber/XMPP PubSub extension (sending notifications by subscription).
- The sig_analog module for analog FXS channels includes the Called Subscriber Held (CSH) feature, which allows the user to place an initiated call on hold, hang up, and resume the conversation by picking up the handset on another phone on the same line. To manage call hold, a setting called subscriberheld is proposed.
- In the res_pjsip_header_funcs function, the prefix argument in PJSIP_HEADERS has been made optional (if not specified, all headers will be returned).
- In the http server (AstHTTP - AMI over HTTP), the display of the status page has been simplified (address and port are now shown on one line).
- The users.conf configuration file has been deprecated.
- The ast_gethostbyname() function has been deprecated and should be replaced by the ast_sockaddr_resolve() and ast_sockaddr_resolve_first_af() functions.
- The SLAStation and SLATrunk applications have been moved from the app_meetme module to app_sla (if using these applications, you should change the modules in modules.conf).
- Modules previously declared obsolete have been removed: chan_skinny, app_osplookup, chan_mgcp, chan_alsa, pbx_builtins, chan_sip, app_cdr, app_macro, res_monitor.
Source: opennet.ru