Configuring Call Handling
Restrictions for Configuring SIP SRST Features Using Back-to-Back User Agent Mode
124
Cisco Unified SCCP and SIP SRST System Administrator Guide
OL-13143-04
Restrictions for Configuring SIP SRST Features Using
Back-to-Back User Agent Mode
•
See the restrictions documented in the
“Restrictions for Configuring Cisco Unified SIP SRST”
section on page 19
section in the
“Cisco Unified SCCP and SIP SRST Feature Overview” section
on page 11
.
Information About Configuring SCCP SRST Call Handling
Cisco Unified SRST offers a smaller set of call handling capabilities than Cisco Unified CM, and much
of the configuration for these feature involves enabling existing Cisco Unified CM or Cisco Unified IP
Phone settings.
•
H.323 VoIP Call Preservation Enhancements for WAN Link Failures, page 124
•
Toll Fraud Prevention, page 124
H.323 VoIP Call Preservation Enhancements for WAN Link Failures
H.323 VoIP call preservation enhancements for WAN link failures sustains connectivity for H.323
topologies where signaling is handled by an entity, such as Cisco Unified Communications Manager,
that is different from the other endpoint and brokers signaling between the two connected parties.
Call preservation is useful when a gateway and the other endpoint (typically a Cisco Unified IP phone)
are collocated at the same site and call agent is remote and therefore more likely to experience
connectivity failures.
For configuration information see “Configuring H.323 Gateways” chapter in
Cisco IOS H.323
Configuration Guide
, Release 12.4T.
Toll Fraud Prevention
When a Cisco router platform is installed with a voice-capable Cisco IOS software image, appropriate
features must be enabled on the platform to prevent potential toll fraud exploitation by unauthorized
users. Deploy these features on all Cisco router Unified Communications applications that process voice
calls, such as Cisco Unified Communications Manager Express (CME), Cisco Survivable Remote Site
Telephony (SRST), Cisco Unified Border Element (UBE), Cisco IOS-based router and standalone
analog and digital PBX and public-switched telephone network (PSTN) gateways, and Cisco
contact-center VoiceXML gateways. For more information about Toll Fraud Prevention, see
Toll Fraud
Prevention
in
Cisco Unified Communications Manager Express System Administration Guide
.