McDewey

Call Forward All, Including CFA Loop Prevention and CFA Loop Breakout Call Forward All (CFA) allows a phone user to forward all calls to a directory number. You can configure CFA for internal and external calls and can forward calls to a voicemail system or a dialed destination number by configuring the calling search space (CSS). Unified Communications Manager includes a secondary Calling Search Space configuration field for CFA. The secondary CSS for CFA combines with the existing CSS for CFA to allow support of the alternate CSS system configuration. When you activate CFA, only the primary and secondary CSS for CFA are used to validate the CFA destination and redirect the call to the CFA destination. If these fields are empty, the null CSS is used. Only the CSS fields that are configured in the primary CSS for CFA and secondary CSS for CFA fields are used. If CFA is activated from the phone, the CFA destination is validated by using the CSS for CFA and the secondary CSS for CFA, and the CFA destination gets written to the database. When a CFA is activated, the CFA destination always gets validated against the CSS for CFA and the secondary CSS for CFA. Unified Communications Manager prevents CFA activation on the phone when a CFA loop is identified. For example, Unified Communications Manager identifies a call forward loop when the user presses the CFwdALL softkey on the phone with directory number 1000 and enters 1001 as the CFA destination, and 1001 has forwarded all calls to directory number 1002, which has forwarded all calls to directory number 1003, which has forwarded all calls to 1000. In this case, Unified Communications Manager identifies that a loop has occurred and prevents CFA activation on the phone with directory number 1000. If the same directory number exists in different partitions, for example, directory number 1000 exists in partitions 1 and 2, Unified Communications Manager allows the CFA activation on the phone. Tip CFA loops do not affect call processing because Unified Communications Manager supports CFA loop breakout, which ensures that if a CFA loop is identified, the call goes through the entire forwarding chain, breaks out of the Call Forward All loop, and the loop is completed as expected, even if CFNA, CFB, or other forwarding options are configured along with CFA for one of the directory numbers in the forwarding chain. For example, the user for the phone with directory number 1000 forwards all calls to directory number 1001, which has forwarded all calls to directory number 1002, which has forwarded all calls to directory number 1000, which creates a CFA loop. In addition, directory number 1002 has configured CFNA to directory number 1004. The user at the phone with directory number 1003 calls directory number 1000, which forwards to 1001, which forwards to 1002. Unified Communications Manager identifies a CFA loop, and the call, which breaks out of the loop, tries to connect to directory number 1002. If the No Answer Ring Duration timer expires before the user for the phone with directory number 1002 answers the call, Unified Communications Manager forwards the call to directory number 1004. For a single call, Unified Communications Manager may identify multiple CFA loops and attempt to connect the call after each loop is identified. Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs 328 Receiving Calls Call Forward All, Including CFA Loop Prevention and CFA Loop Breakout