Cisco Unified SCCP and SIP SRST Feature Overview
Cisco Unified SCCP SRST
17
Cisco Unified SCCP and SIP SRST System Administrator Guide
OL-13143-04
Restrictions for Configuring Cisco Unified SCCP SRST
Table 1
provides a history of restrictions from Cisco SCCP SRST Version 1.0 to the present version of
Cisco Unified SCCP SRST.
Table 1
Restrictions from Cisco SCCP SRST from the Present Version to Version 1.0
Cisco Unified SRST
Version
Cisco IOS
Release
Restrictions
Version 4.1
12.4.(15)T
•
Enhanced 911 Services for Cisco Unified SRST does not interface with the Cisco
Emergency Responder.
•
The information about the most recent phone that called 911 is not preserved after
a reboot of Cisco Unified SRST.
•
Cisco Emergency Responder does not have access to any updates made to the
emergency call history table when remote IP phones are in Cisco Unified SRST
fallback mode. Therefore, if the PSAP calls back after the Cisco Unified IP phones
register back to Cisco Unified Communications Manager, Cisco Emergency
Responder will not have any history of those calls. As a result, those calls will not
get routed to the original 911 caller. Instead, the calls are routed to the default
destination that is configured on Cisco Emergency Responder for the
corresponding ELIN.
•
For Cisco Unified Wireless IP Phone 7920 and 7921, a caller’s location can only be
determined by the static information configured by the system administrator. For
more information, see the
Precautions for Mobile Phones
in
Configuring Enhanced
911 Services
.
•
The extension numbers of 911 callers can be translated to only two emergency
location identification numbers (ELINs) for each emergency response location
(ERL).
•
Using ELINs for multiple purposes can result in unexpected interactions with
existing Cisco Unified SRST features. These multiple uses of an ELIN can include
configuring an ELIN for use as an actual phone number (ephone-dn, voice register
dn, or FXS destination-pattern), a Call Pickup number, or an alias rerouting
number. For more information, see the
Multiple Usages of an ELIN
in
Configuring
Enhanced 911 Services
.
•
There are a number of other ways that your configuration of Enhanced 911 Services
can interact with existing Cisco Unified SRST features and cause unexpected
behavior. For a complete description of interactions between Enhanced 911
Services and existing Cisco Unified SRST features, see the
“Interactions with
Existing Cisco Unified SIP SRST Features” section on page 106
.
