Here's my question: What kind of real-world (or lab) scenario would require disabling SIP supplementary services on an IOS gateway?
Quote from CUCM SRND: SIP Refer or SIP 302 Moved Temporarily messages can be used for supplementary services such as call transfer or call forward on Unified CME or Unified CM to instruct the transferee (referee) or phone being forwarded (forwardee) to initiate a new call to the transfer-to (refer-to) target or forward-to target. No hairpinning is needed for call transfer or call forward scenarios when the SIP Refer or SIP 302 Moved Temporarily message is supported. However, supplementary-service must be disabled if there are certain extensions that have no DID mapping or if Unified CM or Unified CME does not have a dial plan to route the call to the DID in the SIP 302 Moved Temporarily message. When supplementary-service is disabled, Unified CME hairpins the calls or sends a re-invite SIP message to Unified CM to replace the media path to the new called party ID. Both signaling and media are hairpinned, even when multiple Unified CMEs are involved for further call forwards. The supplementary-service can also be disabled for transferred calls. In this case, the SIP Refer message will not be sent to Unified CM, but the transferee (referee) party and transfer-to party (refer-to target) are hairpinned. Note Supplementary services can be disabled with the command no supplementary-service sip moved-temporarily or no supplementary-service sip refer under voice service voip or dial-peer voice xxxx voip. Thanks! Matthew Berry, CCVP, Sr. Unified Communications Engineer Kroll | 9023 Columbine Road, Eden Prairie, MN 55347 Single Number Reach +1 952 516 3748 | Fax +1 952 516 3646 | mjbe...@kroll.com<mailto:david.ra...@kroll.com> www.krollontrack.com<http://www.krollbackgroundscreening.com/> | www.kroll.com
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