The BlackBerry® MVS Client might not be installed on the BlackBerry device or registered with the BlackBerry® Mobile Voice System.

On the BlackBerry device, try performing the following actions:

• Verify that the BlackBerry MVS Client is installed. To view applications on the BlackBerry device, from the Home screen or in the application list, click Options. Click Advanced Options. Click Applications. Look for the BlackBerry MVS Client.
• Verify that the BlackBerry MVS Client is registered with the BlackBerry MVS. If the menu item does not appear on the BlackBerry device, or if the registration fails, see additional troubleshooting topics. If the registration process does not complete, wait for a short period of time and then try again.

The BlackBerry MVS Client might not recognize the caller ID as a call to the work phone number on the BlackBerry device. A user seeing an incorrect caller ID might indicate this cause.

See additional troubleshooting topics on users seeing an incorrect caller ID on the BlackBerry device.

The BlackBerry device might not be active.

Try performing the following actions:

• Verify that the phone is active. In the BlackBerry MVS web UI, on the User menu, click Phones. Beside the BlackBerry device, verify that the Phone On option is selected.
• Verify that the email address for the BlackBerry device is correct for the user's BlackBerry® Enterprise Server user account. In the BlackBerry MVS web UI, on the User menu, click User Profiles. Click the user account. In the Email Address field, verify the email address.
• Verify that the PIN for the BlackBerry device is correct for the user's BlackBerry Enterprise Server user account. In the BlackBerry MVS web UI, on the User menu, click Phones. Click the BlackBerry device. On the MVS tab, in the Device PIN field, verify the PIN.

The Client Network Timing setting for the BlackBerry device might not be configured correctly.

In the BlackBerry MVS web UI, on the Phones screen, verify that the Client Network Timing setting for the BlackBerry device is configured to the network that the BlackBerry device operates on.

A problem might exist with your organization's configuration of the PBX and media gateway.

Try performing the following actions:

• On the PBX, verify that the PBX can route incoming calls to the media gateway. Verify that the PBX can route outgoing calls from the media gateway to the PBX extensions of the BlackBerry MVS users. Verify that the tie trunk group has appropriate permissions to make outgoing calls to external phone numbers over the PSTN.
• On the media gateway, verify that the media gateway can route incoming calls from the PBX to the BlackBerry MVS Server and can route outgoing calls from the BlackBerry MVS to the PBX.