This document walks you through on how to implement anonymous SIP calls in a Cisco Voice Gateway (e.g 28xx/38xx, 29xx/39xx).
1. Enable privacy at the header level in the SIP message. This setting affects all calls (applied globally).
voice service voip sip privacy header
2. This dial-peer configuration prevents the calling-party number from being shown. Per dial-peer configuration.
dial-peer voice 10 voip clid restrict
3. This dial-peer configuration strips calling party name and number when the PI is set to the restrict all clid strip from the CLID information and prevents the calling party name and number from being shown.
dial-peer voice 10 voip clid strip pi-restrict all
4. SIP header manipulation. Can be applied on dial-peer or globally
voice class sip-profiles 1 request ANY sip-header From modify "From: .*>" "From: \"Anonymous\" " dial-peer voice 1 voip voice-class sip profiles 1 *** OR *** voice service voip sip sip-profiles 1