Custom Phone Rings
Cisco IP phones ship with two default ring types that are implemented in hardware: Chirp1 and Chirp2. Cisco CallManager also provides a default set of additional phone ring sounds that are implemented in software as pulse code modulation (PCM) files. The PCM files, along with an XML file (named RingList.xml) that describes the ring list options available at your site reside in the TFTP directory on each Cisco CallManager server.
This appendix describes how you can customize the phone ring types available at your site by creating your own PCM files and editing the RingList.xml file.
Creating a Custom Phone Ring
The following procedure only applies to creating custom phone rings for the Cisco IP Phone 7940 and 7960 models.
Step 1 Create a PCM file for each custom ring (one ring per file). Ensure the PCM files comply with the format guidelines listed in the "PCM File Requirements for Custom Ring Types" section.
Step 2 Use an ASCII editor to edit the RingList.xml file. See the "RingList.xml File Format" section for information about how to format this file, along with a sample RingList.xml file.
Step 3 Save your modifications and close the RingList.xml file.
Step 4 Place the new PCM files you created in the C:\ Program Files\Cisco\TFTPPath directory on the Cisco TFTP server for each Cisco CallManager in your cluster.
RingList.xml File Format
The RingList.xml file defines an XML object that contains a list of phone ring types. Each ring type contains a pointer to the PCM file used for that ring type and the text that will display on the Ring Type menu on a Cisco IP phone for that ring. The C:\ Program Files\Cisco\TFTPPath directory of the Cisco TFTP server for each Cisco CallManager contains this file.
The CiscoIPPhoneRingList XML object uses the following simple tag set to describe the information:
The following characteristics apply to the definition names:
DisplayName defines the name of the custom ring for the associated PCM file that will display on the Ring Type menu of the Cisco IP phone.
FileName specifies the name of the PCM file for the custom ring to associate with DisplayName.
The DisplayName and FileName fields must not exceed 25 characters.
The following sample shows a RingList.xml file that defines two phone ring types:
DisplayName and FileName are required for each phone ring type. The RingList.xml file can include up to 50 ring types.
PCM File Requirements for Custom Ring Types
The PCM files for the rings must meet the following requirements for proper playback on Cisco IP phones:
Raw PCM (no header)
8000 samples per second
8 bits per sample
Maximum ring size 16080 samples
Minimum ring size 240 samples
Number of samples in the ring is evenly divisible by 240.
Ring starts and ends at the zero crossing.
You can use any standard audio editing packages that support these file format requirements to create PCM files for custom phone rings.
You can actually use the Sound Recorder Utility that comes with every Windows 2000 installation.
It allows you to change the format of any .wav file to PCM 8bit 8kHz.
I believe the limit is 50 on the 60's...
Also note that while the 7960's are actually fairly forgiving of violations of some of the ring requirements (particularly sample length) other models - particularly the 7912 are not - so practice doing them right today and you won't frustrate yourself like we did redoing the sound files correctly for the phones that enforce some of the other elements of those requirements :-)
- Ken Johnson
Mgr Network Services
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