Unity MWI in SRST - Please Help

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Jul 10th, 2010
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Hi all:
Can some one Please help me to resolve this issue.

I have configured Unity connection to work in SRST, it is woking okay, but the MWI is NOT working when in SRST.

Can some one please direct me how I can get this thing working in SRST.

My CCM Version: 7.0.1

Unity connection: 7.0

Some info on how I configured  for your details. Your help would me much appreciated

1) PT_VM

2) CSS_VM -----> PT_VM

                  ------> PT_Internal

3) All voice mail ports are using the the above PT and CSS

4) Voicemail pilot 6000 in the CSS_VM

5) MWI on and off are in the PT_VM and CSS_VM

6) Hunt pilot 6000 in the PT_Internal partition ( Hunt list---- line group----- all voice mail ports )

7) In SRST


  voicemail 6000

  call-froward busy 6000

  call-forward noan 6000 timeout 10

  mwi relay

8) dial-peer voice  10

    destination-pattern 6000

    port 0/0/0:23

    prefix 12894146   --------------> where it should come to my main office for voice mail pilot though PSTN

these are the steps I did in order to make it work in SRST, it is working prefectly with out the MWI.

Can some one kindly direct me the steps to do so that I can make the MWI to work in SRST.

I would much Appreciated for your help


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Overall Rating: 4 (1 ratings)
David Hailey Sat, 07/10/2010 - 10:10
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Without knowing your topology, I would note the following:

With SRST, message waiting indicator (MWI) integration is not supported for PSTN access to voice-mail systems at central locations.

In your config, you have the "mwi relay" command entered.  With SRST, the MWI relay mechanism is initiated after someone leaves a voice-mail message on the remote voice-mail message system. MWI relay is required when one Cisco Unity Voice Mail system is shared by multiple Cisco Unified SRST routers. SRST routers use the SIP Subscribe and Notify methods for MWI. See the Configuring Cisco IOS SIP Configuration Guide for more information on SIP MWI and the Subscribe and Notify methods. The SRST router that is the SIP MWI relay server acts as the SIP notifier. The other remote routers act as the SIP subscribers.  In other words, there is more to relay than just a single command in an SRST config.  For more information (and more exact details), go here:


Lastly, there is a new feature in UC 8x called SRSV.  It requires that you run CUCM 8x and CUC 7.1(3) (limited features) or CUC 8x (full-featured).  It is similar in concept to SRST but is for voicemail.  Probably not what you're looking for in your current configuration but is noteworthy moving forward.  The Doc Wiki for SRSV is found here:



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uthth1971 Sat, 07/10/2010 - 15:57
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David Hailey:

Appreciated for your reply. I have seen this document already and tried serveral of the methods that they are saying in SIP configuration.

NONE made it work the MWI in SRST.

MWI is supported in Unity connection 7.0 as per cisco. I am pretty sure it was a configuration issue.

My topology is very simply one, I have one main site and 2 branches. 2 branches are registered with main office. Also 2 branch offices are in h323 with Cisco 3845 routers.

there are some document to talking about unity MWI, but the same steps NOT working in Unity connection.



David Hailey Sat, 07/10/2010 - 18:49
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What you are seeing is expected behavior.  Here is the low down on basic SRST integration capabilities with CUC:

Integrating Cisco Unity Connection with Cisco Unified Survivable Remote Site Telephony (Cisco Unified SRST)

Revised June 2010

Cisco Unified Survivable Remote Site Telephony (SRST) can direct calls to Cisco Unity Connection during Cisco Unified CM fallback. When the WAN is down and Connection has Basic Rate Interface (BRI) or Primary Rate Interface (PRI) access to the Cisco Unified SRST system, Connection uses ISDN signaling (see Figure 7-9).

Figure 7-9     Cisco Unified Communications Manager Fallback with BRI or PRI

When the WAN is down and Connection has foreign exchange office (FXO) or foreign exchange station (FXS) access to a public switched telephone network (PSTN), Connection uses in-band dual tone multifrequency (DTMF) signaling (see Figure 7-10).

Figure 7-10     Cisco Unified Communications Manager Fallback with PSTN

In both configurations, phone message buttons remain active and calls to busy or unanswered numbers are forwarded to Connection. The installer must configure access from the dial peers to the voice-mail system, and establish routing to Connection for busy and unanswered calls and for the message button.

If Connection is accessed over FXO or FXS, you must configure instructions (DTMF patterns) for Connection so it can access the correct voice-mail system mailbox.

When using Cisco Unified SRST with Connection, the integration has the following limitations during a WAN outage:

Call forward to busy greeting—When the Cisco Unified SRST router uses FXO/FXS connections to the PSTN and a call is forwarded from a branch office to Connection, the busy greeting cannot play.

Call forward to internal greeting—When the Cisco Unified SRST router uses FXO/FXS connections to the PSTN and a call is forwarded from a branch office to Connection, the internal greeting cannot play. Because the PSTN provides the calling number of the FXO line, the caller is not identified as a user.

Call transfers—Because an access code is needed to reach the PSTN, call transfers from Connection to a branch office will fail.

Identified user messaging—When the Cisco Unified SRST router uses FXO/FXS connections to the PSTN and a user at a branch office leaves a message or forwards a call, the user is not identified. The caller appears as an unidentified caller.

Message waiting indicationMWIs are not updated on branch office phones, so MWIs will not correctly reflect when new messages arrive or when all messages have been listened to. We recommend resynchronizing MWIs after the WAN link is reestablished.

Message notification—Because an access code is needed to reach the PSTN, message notifications from Connection to a branch office will fail.

Routing rules—When the Cisco Unified SRST router uses FXO/FXS connections to the PSTN and a call arrives from a branch office to Connection (either a direct or forwarded call), routing rules will fail.

When the Cisco Unified SRST router uses PRI or BRI connections, the caller ID for calls from a branch office to Connection may be the full number (exchange plus extension) provided by the PSTN and therefore may not match the extension of the Connection user. In this case, you can let Connection recognize the caller ID by using alternate extensions.

When using Cisco Unified SRST, Redirected Dialed Number Information Service (RDNIS) must be supported.

This is documented here:  http://cisco.biz/en/US/docs/voice_ip_comm/connection/7x/design/guide/7xcucdg050.html#wp1082057

If you have CUC located at the remote site, you can use CME in SRST for VM integration with CUC.  Otherwise, if you want full functionality (or close to it), you'll be looking at SRSV.  SRSV would require a UMG (Messaging Gateway) at the central site and CUE at the remote site.  The UMG syncs with CUC and CUE then syncs with the UMG.  During an outage, CUE kicks in and then resyncs with UMG when connectivity is restored.  SRSV works with Unity Connection as a way to provide mostly seamless voicemail access even when an outage prevents access to a centralized CUC system.



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