Specifications

135
Cisco IOS Survivable Remote Site Telephony Version 3.4 System Administrator Guide
Integrating Voice Mail with Cisco SRST
This chapter describes how to make your existing voice-mail system run on phones connected to a Cisco
Survivable Remote Site Telephony (SRST) router during Cisco CallManager fallback.
Note The Cisco IOS Voice Configuration Library includes a standard library preface, a glossary, and feature
and troubleshooting documents and is located at
http://www.cisco.com/univercd/cc/td/doc/product/software/ios123/123cgcr/vcl.htm.
Contents
• Information About Integrating Voice Mail with Cisco SRST, page 135
• How to Integrate Voice Mail with Cisco SRST, page 137
• Configuration Examples, page 149
• Where to Go Next, page 151
Information About Integrating Voice Mail with Cisco SRST
Cisco SRST can send and receive voice-mail messages from Cisco Unity and other voice-mail systems
during Cisco CallManager fallback. When the WAN is down, a voice-mail system with BRI or PRI
access to the Cisco SRST system uses ISDN signaling (see Figure 8). Systems with Foreign Exchange
Office (FXO) or Foreign Exchange Station (FXS) access connect to a PSTN and use in-band dual tone
multifrequency (DTMF) signaling (see Figure 9).