Certified Asterisk is a branch of Asterisk supported by Digium for commercial SLA customers entitled under certain Support offerings. Like other branches of Asterisk, it is provided under GPLv2 license and may be used freely by anyone, even users and other customers who are not Digium’s SLA customers.
Releases are made at longer intervals, between 2 and 4 times annually, as opposed to the once-per-month cycle of mainline Asterisk releases; and are curated to minimize change and support longer quality assurance windows. This allows SLA customers to minimize the uncertainty of accepting large or frequent code updates. Each Certified Asterisk release begins as a selected mainline Asterisk point release that undergoes a rigorous and extended internal testing process. At the completion of the testing process, a new release is made, and SLA customers may begin receiving support, as dictated by their support agreements, on that release.
Releases of Certified Asterisk are made against the current Asterisk LTS codebase, presently 13, not against Asterisk Standard releases, e.g. 10 or 12, and represent a snapshot of the mainline Asterisk LTS release, branched and maintained with SLA customer bug fixes. Each release is versioned according to: asterisk-MainlineBranchPoint-certX, e.g. asterisk-13.1-cert2, where MainlineBranchPoint indicates the Asterisk release point at which the branch occurred and X represents the bug-fix release version of a particular release of Certified Asterisk. Bug-fix releases of Certified Asterisk are made for the duration of customer support agreements; and, following 1.8, new releases of Certified Asterisk have been made against Asterisk 11 and 13 LTS versions. This schedule provides customers the flexibility to migrate from one release to another, with overlapping support between major versions of Certified Asterisk.