Cisco 7975G Software Manual page 162

Telephony Features Available for Cisco Unified IP Phone
Feature Description
RTCP Hold For SIP The RTCP Hold For SIP feature ensures that held calls
are not dropped by the gateway. The gateway checks the
status of the RTCP port to determine if a call is active or
not. By keeping the phone port open, the gateway will
not end held calls.
Enable the RTCP option on the Cisco Unified
Communications Manager to support this feature.
Cisco Unified IP Phone 7975G, 7971G-GE, 7970G, 7965G, and 7945G Administration Guide for Cisco Unified
Communications Manager 9.0 (SCCP and SIP)
142
Features, Templates, Services, and Users
Configuration reference
No configuration required.