Cisco Unified MeetingPlace, Release 7.0 -- How to Resolve Problems That Occur During Calls

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Main page: Cisco Unified MeetingPlace, Release 7.0

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System Does Not Detect Key Presses

Problem: The system does not detect user input through the telephone user interface (TUI).

Solution:

  1. Log into the CLI.
  2. Troubleshoot a call in real time by completing these steps:
    1. Enter the following command:
      eventlog -G -t
    2. Place a test call to the system.
    3. Press phone keys in response to the voice prompts.
  3. In the log, look for DTMFEVENT and mcpLegNotification messages, each pair of which would indicate that Cisco Unified MeetingPlace received the user input of a single digit.
    The following sample log output shows that at 10:42:04, a caller on port 0 pressed the "1" key on the phone:


08/28 10:42:04.95 P 0 RN MC mcpLegNotification (1)

08/28 10:42:04.95 P 0 SE CP m=017 DTMFEVENT Resp 0


4. If you do not see DTMFEVENT and mcpLegNotification messages in the log, make sure that your call-control devices are set up to transport DTMF digits:

a. In Cisco Unified Communications Manager SIP trunks to Cisco Unified MeetingPlace, make sure that the DTMF Signaling Method is set to No Preference.

b. If the call passes through a voice gateway, then you may need to configure that gateway to use DTMF relay to transport DTMF digits.

c. On the Media Parameters Page, try setting the "Enable in-band DTMF detection" field to Yes.

d. Make sure that the Media Server is correctly configured. See Configuring the Media Server Using the MSA Interface.


5. If you do see DTMFEVENT and mcpLegNotification messages in the log, check the alarm table for TUI-related issues, and resolve them.


Related Topics




One-Way Audio-User Cannot Be Heard By Other Participants

Problem: User gets one-way audio only. User can hear the voice meeting, but other participants cannot hear the user.

Solution: Make sure that the user is not muted:

  • Have the user check for a mute button on the phone or video endpoint.
  • If still in the voice meeting, have the user press #5 on the phone, in case another meeting participant muted the line.




User "Talk-Off" (Triggering the Pound Key with Your Voice)

Talk-off is the unexpected detection of a digit (often a # key) by voice systems such as Cisco Unified MeetingPlace.


This is always a statistical possibility due to the imperfect nature of in-band (voice and DTMF sharing the same voice channel) DTMF tone detection algorithms in any voice device (Cisco Unified MeetingPlace, PSTN voice gateways). Ideally, in-band DTMF detection in these devices will correctly detect digits 100% of the time with no false detection of voice as digits. Practically, a small number of errors -- some voice will be falsely detected as a digit (aka "talk-off") -- are allowed. While most cases of talk-off cause no reaction in Cisco Unified MeetingPlace during a meeting -- false detection of any number "1" to "9" or "*" -- and are ignored, false detection of "#" or "0" can cause unexpected Cisco Unified MeetingPlace behavior.


The Cisco Unified MeetingPlace in-band DTMF detector meets the requirements of the "Bellcore Talk-off Test" specifications. The spec allows up to 500 false detections of any digit "0" to "9", "#" and "*" after the three hour test with real voice snippets. Cisco Unified MeetingPlace measures at 356 false detects for all these digits with only four false "#" and four false "0" digit detects during this period. So the Cisco Unified MeetingPlace DTMF detector exceeds the Bellcore spec and changes to the DTMF detection algorithm are very unlikely.


Realistically, though, people are all different. Unfortunately, some voices and speech patterns are more prone to triggering the DTMF detector than others, so certain users may have a much higher probability of seeing this problem.


Recommendations:

  • For System Administrators: Use out-of-band digit transmission (RFC-2833, KPML) wherever possible. However, using RFC-2833 may only shift the talk-off problem from the Cisco Unified MeetingPlace DTMF detector to a voice gateway DTMF detector.
  • For End Users: Use the best possible audio connection -- a land-line or a good IP connection with G.711. In some cases cordless phones may distort speech enough to make a user prone to talk-off.
  • For End Users: While it may be nearly impossible to avoid, users who are prone to triggering false "#" digits usually speak something like "umm" for a relatively long period of time. These sounds should be avoided or at least shortened.

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