New Features In Cisco Unified Srst Version 3.4; New Features In Cisco Srst Version 3.3 - Cisco CP-7911G-CH1 System Administrator Manual

Information About New Features in Cisco Unified SRST

New Features in Cisco Unified SRST Version 3.4

Cisco SRST V3.4 introduced the new features described in the following section:
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Cisco SIP SRST 3.4
Cisco SIP SRST Version 3.4 describes SRST functionality for Session Initiation Protocol (SIP)
networks. Cisco SIP SRST Version 3.4 provides backup to an external SIP proxy server by providing
basic registrar and back-to-back user agent (B2BUA) services. These services are used by a SIP IP phone
in the event of a WAN connection outage when the SIP phone is unable to communicate with its primary
SIP proxy.
Cisco SIP SRST Version 3.4 can support SIP phones with standard RFC 3261 feature support locally and
across SIP WAN networks. With Cisco SIP SRST Version 3.4, SIP phones can place calls across SIP
networks in the same way as Skinny Client Control Protocol (SCCP) phones. For full information about
SIP SRST, Version 3.4, see

New Features in Cisco SRST Version 3.3

Cisco SRST V3.3 introduced the new features described in the following sections:
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•
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Secure SRST
Secure Cisco IP phones that are located at remote sites and that are attached to gateway routers can
communicate securely with Cisco Unified Communications Manager using the WAN. But if the WAN
link or Cisco Unified Communications Manager goes down, all communication through the remote
phones becomes nonsecure. To overcome this situation, gateway routers can now function in secure
SRST mode, which activates when the WAN link or Cisco Unified Communications Manager goes
down. When the WAN link or Cisco Unified Communications Manager is restored, Cisco Unified
Communications Manager resumes secure call-handling capabilities.
Secure SRST provides new SRST security features such as authentication, integrity, and media
encryption. Authentication provides assurance to one party that another party is whom it claims to be.
Integrity provides assurance that the given data has not been altered between the entities. Encryption
implies confidentiality; that is, that no one can read the data except the intended recipient. These security
features allow privacy for SRST voice calls and protect against voice security violations and identity
theft. For more information see the
Cisco Unified SCCP and SIP SRST System Administrator Guide
48
Cisco SIP SRST 3.4, page 48
Cisco SIP SRST Version 3.4 System Administrator
Secure SRST, page 48
Cisco Unified IP Phone 7970G and Cisco Unified 7971G-GE Support, page 49
Enhancement to the show ephone Command, page 49
Cisco Unified Survivable Remote Site Telephony Feature Roadmap
"Configuring Secure SRST for SCCP and SIP" section on page
Guide.
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