First we've to understand Cisco IP Phone Registration & Boot UP Sequence>
Phone Registration Process
Step 1: Phone Loads Software (Image) and Starts the Configuration Process
Step 2a: Phone Sends DHCP Request
Step 2b: DHCP Server Sends DHCP Response
Step 3a: Phone Sends TFTP Request for a Configuration File
Step 3b: TFTP Server Sends the Default Configuration File
Step 4a: TFTP Server Sends the Specific Configuration File of the Phone
Step 4b: Phone Registration Finishes
FIRST UNDERSTAND THE BOOTUP PROCESS, START TROUBLESHOOTING ACCORDING:
General Troubleshooting Sequence:
- Disable DHCP and DNS to Test a Phone
- Check for the Incorrect MAC Address on the Phone Label
- Cisco CallManager and TFTP Services Do Not Run
- Delete and Recreate a Phone
- Understand a Network Trace File
- Use Performance Monitor to Analyze Phone Activity
- Manually Configure the IP Parameters on a 12 SP+ or 30 VIP Phone
- Add Phones to Cisco CallManager
- Enable, Configure, and Disable Auto−Registration
- Manual Registration (Add an IP Phone Manually) etc....
THESE ISSUES COULD BE THERE:
- IP Phone Registration Toggles between Primary and Secondary CallManagers.
- Registration Rejected
- Cisco IP Phones Not Registered But seems to be working fine.
- Cisco IP Phones Take Too Long to Register.
- Cisco IP Phone Always Get Registered to the Publisher Server.
- Get "version error" on the Cisco IP Phone screen When Try to Register.
- Cisco phones causing excessive DHCP requests.
Diagram/Flowchart representing, CISCO IP Phone Boot UP Process:
[DOWNLOAD THE ATTACHED PNG FILE @ LAST]
Step 1: Phone Loads Software (Image) and Starts the Configuration Process:
During this step, these issues could be there,
* Registration with a Cisco CallManager server is successful only when the server adds the phone or when the server has Auto−Registration enabled. (The default for Auto−Registration is disabled.)
* Note: If the phone LCD screen does not light up, you could have a faulty phone. The phone also could be
faulty if the message the phone displays never changes after you plug in the phone. Contact Cisco Technical
Support to request a replacement if your phone is under warranty.
* If your phones do not use DHCP, see the Step 3a: Phone Sends TFTP Request for a Configuration File section
of this document.
Step 2a: Phone Sends DHCP Request:
During this step, these issues could be there,
For Cisco 7940 and 7960: (to manually enable the DHCP Parameter on the phone itself):
Complete these steps on the Cisco 7940 and 7960:
1. Choose Settings.
2. Choose 3 (Network).
Scroll down to the DHCP Enabled parameter.
The selection must be Yes.
__________
Complete these steps on the Cisco 7910:
1. Choose Settings.
2. Choose 6 (Network).
3. Scroll down to the DHCP Enabled parameter.
The selection must be Yes.
__________
Cisco 12 SP+ and 30 VIP
Complete these steps on the Cisco 12 SP+ and 30 VIP:
1. Enter **#.
2. Enter 1.
3. Set all parameters to zero (0).
Note:
Cisco 7910G supports only 10 MB speed, but 7910G+SW supports 10/100. If you have a 7910G, be sure to set the switch port that connects to the phone to 10 MB or Auto.
Any IP parameters that you have hard coded on the phones override the parameters that the DHCP server provides. In particular, the Alternate TFTP Server option overrides the TFTP server IP address that the DHCP provides. For information on how to reset your phone configuration to the original
factory defaults, refer to either of these documents:
¨ Resetting 7900 Series IP Phones to Factory Defaults
Step 2b: DHCP Server Sends DHCP Response:
The DHCP response contains the phone IP address and the IP address of the TFTP server (which is usually a
Cisco CallManager server). The response can also contain any of or all these common options:
· IP address of the default router (gateway)
· IP address of the Domain Name System (DNS) server
· Domain name
includes option 150 for the TFTP server.
Step 3a: Phone Sends TFTP Request for a Configuration File:
- The phone requests a specific configuration file. The name for this file is SEPMAC−Address.cnf. For
example, the file name for a phone with the MAC address 0030.94C2.D5CA is SEP003094C2D5CA.cnf. If
the file exists on the Cisco CallManager server, see the Step 4a: TFTP Server Sends the Specific
Configuration File of the Phone section of this document.
- If the phone is not in the Cisco CallManager database, the request for the specific configuration file results in
a TFTP File Not Found response from the TFTP server. The phone then requests the file with the name
SEPDEFAULT.cnf. If you have configured the Cisco CallManager server for Auto−Registration, this file
exists and the server sends it to the phone. See the Step 3b: TFTP Server Sends the Default Configuration File
section of this document.
Otherwise, the TFTP server of the Cisco CallManager server sends another File Not Found TFTP
response. At this point, the phone restarts the configuration process.
Step 3b: TFTP Server Sends the Default Configuration File:
Note: This step only occurs if you have enabled Auto−Registration and the phone has not already registered
with the Cisco CallManager server.
If you have configured the Cisco CallManager server for Auto−Registration, it sends the SEPDEFAULT.cnf
file in response to the phone request. After the Cisco CallManager server database adds a phone by
Auto−Registration, the phone has a SEPMAC−Address.cnf file. It does not reference the SEPDEFAULT.cnf
again.
Step 4a: TFTP Server Sends the Specific Configuration File of the Phone:
Note: This step only takes place if the phone creation occurred on the Cisco CallManager server.
The configuration file contains several parameters for the phone. These include the device pool, the Cisco
CallManager servers to use, configured speed dials, and other parameters. In general, any time you make a
change in Cisco CallManager that requires the phone (device) to be reset, you have made a change to the
phone configuration file.
Step 4b: Phone Registration Finishes:
The Cisco CallManager server sends the phone additional configuration elements during the final phases of
the registration process.
In general, the registration process must complete successfully if the process goes this far.
To learn what takes place at this point, you need to set up a network analyzer to capture the IP packets that the phone sends to and receives from the server.
FACTS:
7961G Phone does not Register until it is Configured as a 7961>
IP phones CP−7961 and CP−7961G are basically the same platform. The G stands for global use that supports all languages.
So when you add a 7961G phone, you should add it as a regular 7961 phone. CP−7961G−GE is another IP phone with two gigabit Ethernet ports (10/100/1000).
If IP phone 7961G is added as 7961G−GE, it does not register with Cisco CallManager.
TASKS TO PERFORM:
Disable DHCP and DNS to Test a Phone
Check for the Incorrect MAC Address on the Phone Label
Cisco CallManager and TFTP Services Do Not Run
Delete and Recreate a Phone
Understand a Network Trace File
Use Network Monitor to Analyze Phone Activity
By default, Cisco phones are DHCP−enabled. If you do not use DHCP, you need to disable DHCP on the phone and manually assign the phone an IP address. In order to disable DHCP on a phone, use the phone keypad to program the phone IP address and other network addresses.
Enable, Configure, and Disable Auto−Registration
Manual Registration (Add an IP Phone Manually)
Note: If you have your Cisco CallManager servers set up in a cluster, every server has the configuration files
for every phone that is in the Publisher database. Therefore, any Cisco CallManager server can serve as a
TFTP server for the phones. The device pools to which you have assigned the phones determine the server
with which the phones register. A phone can obtain the configuration file from a different server than the
server with which the phone registers.
Thanks:
Mohit Grover
