In this blog, we will discuss SRST voicemail capabilities. The information in this blog assumes some information from previous blog postings on SRST. This SRST blog is the eighth SRST post in the SRST blog series.
During normal operation, a message waiting indicator (MWI) is sent from the Cisco Unity voicemail server to the Cisco IP Phone to indicate a new voicemail message. The red MWI light illuminates on the Cisco IP phone and a mail icon appears next to the directory number with a voicemail. Branch phone can retrieve voicemail during a WAN outage, but MWIs will not work when the phones are registered to the SRST router. The voicemail button must be provisioned in SRST configuration and the voicemail server must be accessible from PSTN (normally a DiD number).
With the following call-manager-fallback configuration, clicking the voicemail button will result in a call placed to the voicemail direct inward dialing number over the ISDN PRI:
Voicemail 918458967000
The following call forwarding configuration will forward all busy and no answer conditions to the voicemail DiD phone number.
call-forward busy 918458967000
call-forward noan 918458967000 timeout seconds 20
Call forwarding to voicemail requires RDNIS (redirected dialed number information service) support. Most analog circuits do not support RDNIS, but ISDN circuits do. If the provider analog circuit does provide RDNIS support, it is not enabled on the Cisco voice gateway by default. The following configuration must be configured in the analog gateway to properly forward the original calling and original called party to the voicemail system.
vm-integration
pattern direct 2 CGN *
pattern ext-to-ext no-answer 5 FDN * CGN *
pattern ext-to-ext busy 7 FDN * CGN *
pattern trunk-to-ext no-answer 4 FDN * CGN *
pattern trunk-to-ext busy 6 FDN * CGN *
In the next blog, I will discuss RDNIS in more detail and we will continue the SRST conversation.
Dennis Hartmann, CCIE No. 15651, is a consultant with www.highpoint.com and author of Implementing Cisco Unified Communications Manager, Part 1. Dennis is also a lead instructor at Global Knowledge. Dennis has various certifications, including the Cisco CCVP, CCSI, CCNP, CCIP, and the Microsoft MCSE. Dennis has various specializations including unified communications, data center, routing & switching, service provider (MPLS and optical). Dennis has worked for various Fortune 500 companies, including AT&T, Sprint, Merrill Lynch, KPMG, and Cabletron Systems. He lives with his wife and children in Hopewell Junction, New York.
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