Cisco Unified SRST Versions and Feature Support
Table 5-2 describes Cisco Unified SRST versions, their protocol support and features, and the required Cisco IOS Software release.
Table 5-2. Cisco Unified SRST Versions
Feature |
CUCM Express in SRST Mode |
Cisco Unified SRST 8.0 |
Cisco Unified SRST 7.2 |
Cisco Unified SRST 4.3 |
Minimum Cisco IOS Software Release |
12.3(11)XJ 15.0(1) for version 8.0 |
15.0(1)XA |
12.4(22)YB 15.0(1)M on ISR G2 |
12.4(11)XZ |
Presence |
||||
Extension Mobility |
||||
Eight active calls per line |
(new in 8.0) |
|||
Support for E.164 numbers with + prefix |
(new in 8.0) |
|||
Five additional MOH* streams (SCCP only) |
(new in 8.0) |
The version of the Cisco Unified SRST application depends on which release of the Cisco IOS Software is running on the router. Each Cisco IOS Software release implements a particular SRST version. You upgrade to a newer version of SRST through a Cisco IOS update into router flash. Recent Cisco IOS Software releases often have higher memory requirements than older ones, so make sure that you look into this before upgrading.
For detailed information about Cisco Unified SRST versions and their hardware and feature support, refer to the Cisco Unified Survivable Remote Site Telephony Version 8.0 data sheet at www.cisco.com/en/US/prod/collateral/voicesw/ps6788/vcallcon/ps2169/data_sheet_c78-570481.html.
SRST 4.0 Platform Density
The maximum number of IP Phones and directory numbers supported by the Cisco Unified SRST 8.0 feature depends on which Cisco IOS router platform is used, as shown in Table 5-3.
Table 5-3. SRST 8.0 Platform Density
Platform |
Maximum Number of IP Phones |
800 Series |
4 |
1861 |
15 |
2801–2851 |
25–100 |
2901–2951 |
35–250 |
3825, 3845 |
350, 730 |
3925–3945E |
730–1500 |
Table 5-3 shows the maximum number of phones and DNs on phones that a Cisco Unified SRST router can accommodate For more details, such as minimum memory requirements, see Cisco Unified SRST 8.0 Supported Firmware, Platforms, Memory, and Voice Products at www.cisco.com/en/US/docs/voice_ip_comm/cusrst/requirements/guide/srs80spc.html.