IP Phone Auto Registration

Auto registration allows CUCM to issue extension numbers to new IP phones, which is similar to the way in which the DHCP server issues IP addresses.

With auto registration configured and enabled, when a new IP phone boots and attempts to register with CUCM for the first time, CUCM issues an extension number from a configured range. After CUCM issues the extension, it adds the phone to its configuration database with the used device ID (MAC address) and the assigned extension.

If a specific extension is intended to be used for a phone, the automatically assigned extension has to be modified.

Auto registration eases only one small part when adding a high number of IP phones: The MAC addresses of the phones are automatically added to the CUCM configuration database. The extensions, however, still have to be modified per phone.

If a large number of phone settings need to be changed, CUCM BAT can be used to alter the phone configurations.

NOTE For large deployments, the CUCM Auto-Register Phone tool can be used, which allows specific extensions to be assigned to individual phones based on user input.

Auto registration is supported by all Cisco IP Phones and does not affect IP phones that are already configured.

Auto registration occurs as part of the IP phone startup process, at the point where the IP phone tries to download its configuration file from the TFTP server. Assuming the IP phone has a MAC address of 0015C5AABBDD, the following will happen:

1. The Cisco IP Phone attempts to download configuration from the TFTP server. The TFTP server does not contain a configuration file for this phone (that is, SEP0015C5AABBDD.cnf.xml) because the phone does not have a unique configuration in CUCM. Each preconfigured phone in CUCM will have a unique XML configuration file corresponding to the configuration in CUCM. The TFTP server returns "Read Error" to the IP phone TFTP request.

2. The IP phone then queries the TFTP server for the XmlDefault.cnf.xml file. CUCM automatically creates a phone device record in the configuration database and assigns a directory number (DN) to the first line of the device based on the auto-registration DN range. A configuration file (SEP0015C5AABBDD.cnf.xml) is created and added to the TFTP server.

3. The IP phone updates its firmware if the load information defined in the configuration file is an older or newer version than the one the phone is currently running.

4. The IP phone registers to the CUCM server configured for auto registration and specified in the file XmlDefault.cnf.xml.

Administrators should carefully evaluate auto registration before implementing it, because its use can pose a security risk to the network. Auto registration allows anyone with physical access to the voice network to connect an IP phone and use it, whether authorized or not. Auto registration is turned off by default. The security risks of auto registration can be minimized by applying partitions to all route patterns in the system. This topic is covered in more detail in Chapter 13, "Calling Privileges."

A range of DNs must be configured on CUCM for auto registration. CUCM assigns the next available DN out of the configured range. One DN is assigned per IP phone. The administrator cannot control which DN will be allocated on a per-device basis.

The default protocol for auto-registered IP phones is set globally within the cluster and can be set to either SIP or SCCP. For endpoints that are both SIP and SCCP capable, it automatically converts the endpoint firmware to match to the default auto-registration protocols. Endpoints that support only one protocol will still be able to auto register even if the autoregistration protocol is set to the other protocol.

Auto-Registration Configuration

There are four steps involved in configuring for auto registration; the fourth step is optional, although commonly required:

Step 1 Verify that the desired auto-registration default protocol is selected.

Step 2 Ensure that auto registration is enabled on one CUCM group.

Step 3 Configure CUCM member servers of that group selectively to be used for auto registration, and if enabled on a particular server, set this server's DN range.

Step 4 (Optional) Reconfigure the automatically added phones, applying the individually required configuration settings. This can be done using CUCM BAT for groups of phones that share some settings or manually for each phone.

The default auto-registration protocol is an enterprise parameter, configured under System > Enterprise Parameters. This parameter specifies the protocol that should be used on Cisco IP Phones that support SCCP and SIP.

The default auto-registration protocol is SCCP. Restart all services for the parameter change to take effect. Figure 9-15 displays the auto-registration phone protocol enterprise parameter.

Figure 9-15 Auto-Registration Phone Protocol

Auto-Registration Phone Protocol

Auto-Registration Phone Protocol

Enterprise Parameters Configuration

Save Set to Default ^j) Reset

Enterprise Parameters Configuration

Parameter Name

Parameter Value

Suggested Value

Synchronization Between Auto Device Profile and Phone

1 Tme



ConfiauratiDn *

Max Number of Device Level Trace *



DSCP for Phone-based Services *

| default DSCP (000000)


default DSCP (000000)

DSCP for Phone Configuration *

| CS3(precedence 3) DSCP (011000)


CS3(precedence 3) DSCP (011000)

DSCP for Cisco CallManaqer to Device Interface *

| CS3fprecedence 3) DSCP (011000)


CS3(precedence 3) DSCP (011000)

I: - - ~ : r i: - : -. r z - I u "riic - '



- ' _ j i - i - -___ +




BLF For Call Lists *



1 [sip

Advertise G.722 Codec *


Phone Personalization *



CCMAdmin Parameters

Max List Box Items *



Max LookuD Items *

|100D ~


Enable Dependency Records *

1 False



Auto registration can be enabled only on one CUCM group. Checking the Enable AutoRegistration check box on one CUCM group automatically disables the check box on the group that had auto registration enabled before (if applicable). Navigate to System > Cisco Unified CM Group and select the group that should provide the auto-registration service, and then check the Enable Auto-Registration check box. Figure 9-16 displays the default Cisco Unified CM Group Configuration page.

Figure 9-16 Auto Registration: CUCM Group Configuration

Enable Auto-Registration

Figure 9-16 Auto Registration: CUCM Group Configuration

Auto Registration Cucm

Complete these steps to enable auto registration on a specific CUCM server; this server has to be a member of the CUCM group that is configured for auto registration.

Step 1 From CUCM Administration, choose System > CUCM.

Step 2 Click Find, and then from the list of CUCM servers, choose the server that should be configured for auto registration.

Step 3 Under the Auto-Registration Information section, enter the appropriate DN range in the Starting and Ending Directory Number fields.

Step 4 Ensure that the Auto-Registration Disabled on this Cisco Unified Communications Manager check box is unchecked.

Step 5 Click Save.

Figure 9-17 displays the Cisco Unified CM Configuration page. Figure 9-17 Figure 9-17 Cisco Unified CM Configuration

Enter DN Range for Auto-Registration

Enter DN Range for Auto-Registration

Figure 9-17 displays the Cisco Unified CM Configuration page. Figure 9-17 Figure 9-17 Cisco Unified CM Configuration

Enable Auto-Registration

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  • marcus
    What is auto registration in cucm?
    1 year ago
  • michael goldschmidt
    How to register phone in cisco unified cm admin?
    1 year ago
  • tullio beneventi
    Which item is mandatory to enable the autoregistration tool?
    8 months ago
    How to find auto registered phones, manager?
    5 months ago
  • ANN
    What is auto registration cisco?
    5 months ago
  • sarah
    How phones registers in cucm?
    5 months ago
  • Eilidh
    How to register Cisco IP Phones with CUCM?
    4 months ago
  • Aamu
    How to configure autoregistration on cucm?
    3 months ago

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