IP PHONE REGISTRATION ISSUES

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Mon, 11/30/2015 - 02:09
Sep 28th, 2012
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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:

  1. IP Phone Registration Toggles between Primary and      Secondary CallManagers.
  2. Registration Rejected
  3. Cisco IP Phones Not Registered But seems to be working      fine.
  4. Cisco IP Phones Take Too Long to Register.
  5. Cisco IP Phone Always Get Registered to the Publisher      Server.
  6. Get "version error" on the Cisco IP Phone      screen When Try to Register.
  7. 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

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CT (not verified) Sat, 06/01/2013 - 02:13
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thank you so much! god bless!

karthikeyan swa... Sun, 08/23/2015 - 09:33
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Hello Mohit,

 

Nice explanation. Can you please tell me ip phone registration process in terms of SCCP and SIP protocol. What is the difference between those two protocols in-terms of registration perspective

chridiaz Fri, 10/02/2015 - 18:50
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  • Cisco Employee,

Hello,

 

I'm having issues registering a phone. This is a lab environment. If I connect the ip phone to the wall port it automatically registers to cucm via dhcp. I took a switch and connected to the port the phone was connected to. The phone gets power and the switch sees the phone but the phone is not registering. Any idea what can happening here? No security is configured on the switch.

 

 

Mohit Grover Sat, 10/03/2015 - 00:23
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  • Cisco Employee,

 

Hi,

 

Did you configure VLAN on the Switch/Module ?

Is the phone getting IP address from DHCP ?

On which device DHCP is configured ?

Clear the status messages, reset the endpoint & verify the status messages output.

What do you see on the Phone display ?

 

chridiaz Sat, 10/03/2015 - 05:25
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  • Cisco Employee,

Mohit,

I did configure vlan as access mode. When I plug the phone directly into the wall port it receives an ip from dhcp, keep in mind since this is a corporate network I do not have access to configure the dhcp. However, when I plug the switch to the wall port, then the phone to the switch is not getting an ip. I did reset endpoint and the phone just stays in configuring ip mode. I'm wondering if I'm missing a command on the switch. I would appreciate any help.

 

 

ra 011 Wed, 11/25/2015 - 02:24
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i have an issue

i have cucm pub and sub and tftp is the pub and 1st server in cm group is the sub and phones cannot register with subscriber it registers only with publisher

it gives error if i force it to register with sub says " registration rejected : security error "

sreeharikt Wed, 11/25/2015 - 22:39
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If the IP Phone has never been entered into the CallManager database via CallManager Administration, CallManager does not allow that phone to register unless auto-registration is enabled. Auto-registration does not work unless it has available directory numbers to provide the registering IP Phone a DN. If the IP Phone is not configured in CallManager Administration and auto-registration is not enabled or CallManager has run out of DNs, the phone displays "Registration Rejected."

In some cases, the phone might be having old residual security config that is no longer needed, in such case you need to factory reset.

ra 011 Mon, 11/30/2015 - 02:09
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the phone is already  registered well with cucm pub but cannot register with sub and i have tried resetting the phone but same issue does i need to upload certificate from pub to sub ?


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