# About IP Phone Registration in a Cluster

During normal operation, each IP Phone is controlled from its primary MiVoice Business system. The IP Phone's directory number (DN) is programmed in the Telephone Directory form of its primary system and referenced in the Remote Directory Numbers of the other cluster elements. Before an IP Phone can function, it must be able to register with its primary system. If there are multiple MiVoice Business systems in a single Dynamic Host Configuration Protocol (DHCP) domain, or if an IP Phone is moved from one DHCP domain to another, the IP Phones must be able to detect the IP address of its primary system.

You must configure a cluster to allow the IP Phones to detect the IP addresses of the MiVoice Business systems by programming each system to resolve the DN of an IP phone to its CEID digits, to its ICP/PBX ID and finally to its IP address. In a cluster, each MiVoice Business system knows the IP addresses of the other systems because they communicate using IP trunking. Therefore, if a cluster is configured correctly, an IP Phone can detect the IP address of its primary system from anywhere in the cluster.

The following conditions apply to IP Phone registration in a cluster:

- IP Phone registration is supported for multiple controllers in one DHCP Domain so you can move an IP Phone from one DHCP Domain to another DHCP Domain. A DHCP domain can span one or more IP network subnets and one or more VLANs.

- The following devices do not support IP Phone registration across a cluster. You must manually program these devices and applications with the IP address of their primary MiVoice Business system:

- 4000 series IP Phones

- 5485 paging unit

- 6500 Unified Communications application

- The registration access codes for the IP Phone PIN must be identical on all MiVoice Business systems in the cluster. The replacement access codes must also be identical. These access codes, typically 3 characters in length, can be a maximum of ten characters long.

- Each MiVoice Business system must use IP trunking or TDM DPNSS trunking to communicate with the other systems in the cluster.

- If there is more than one TFTP server in the cluster, all TFTP servers have the same IP phone firmware.

- When moving an IP Phone from one subnet to another subnet, you must power down the IP Phone. If you don't power it down the IP Phone will display "Waiting for Link" because the IP gateway in the new subnet will be unable to resolve the IP address for the registration request from the IP Phone.

- The PBX Number that you program in the ICP/PBX Networking form for an element must match the element's CEID index.

- Each IP Phone in the IP cluster must be able to retrieve the IP address of at least one of the MiVoice Business systems in the IP cluster.

NOTE: If you wish to register IP Phones as Userless Device
An IP device configured with service level "IP Device Only"; provides basic functionality (emergency/attendant calls and hot desk login) and does not require a license.s that will be hosted by the same (primary) node, you can use the Automatic DN Selection method to speed up and simplify the installation and registration process. See Registering and Auto-provisioning Multiline IP Telephones without a DN for details.

## Registration Sequence for an IP Phone

The IP Phone saves the PIN in the phone memory. To change the DN of the IP Phone after it has successfully registered with an MiVoice Business system, you must delete the DN of the IP Phone from the Telephone Directory form. The IP Phone will then reset and the user will be prompted to enter a new PIN. The following conditions apply:

- If you use the System Administration Tool to change the DN of a registered IP Phone, the phone will be assigned the new DN. However the next time the IP Phone is powered up, it will prompt the user to enter a PIN because the PIN that was assigned to the previous DN in phone memory is no longer valid.

- If the MAC address of the IP Phone is deleted from the MiVoice Business database, the IP Phone will reset and then register automatically with its proper controller. The registration sequence automatically puts the MAC address of the IP Phone back into the controller database.

- If you move existing DNs between MiVoice Business systems in a cluster, the remote directory numbers must be updated accordingly through a synchronization event.

## Replacement Sequence for an IP Phone

The IP Phone saves the PIN with a replacement code in the phone memory. If you delete the MAC address of the IP Phone from the MiVoice Business database, the IP Phone will reset and then prompt the user for a PIN. The user is prompted for a PIN because the replacement code does not work unless the DN is programmed with a MAC in the MiVoice Business system. The following conditions apply:

- To change the DN of the IP Phone after it has successfully registered with its MiVoice Business system, delete the DN of the IP Phone. The IP Phone will reset and the user will be prompted to enter a new PIN.

- If you use the System Administration Tool to change the DN of a registered IP Phone, the phone is assigned the new DN. However, the next time that the IP Phone is powered on it will prompt the user for a PIN because the PIN that was associate with the old DN in the phone's memory is no longer valid.

- Moving existing DNs between MiVoice Business elements provided that you change the remote directory numbers accordingly.

## IP Phone Registration Example

NOTE: For Container-based MiVoice Business (cMiVB), FQDN is used instead of the IP address for the call server.

When a phone is powered up, it gets an IP address, accesses a TFTP server, and downloads its boot files. Next, it attempts to register with the MiVoice Business system at the IP Address that was identified by DHCP Option 125.

The phone checks for a PIN stored in its memory and then sends the PIN and its MAC address to its controller. If there is no PIN stored, it sends a null value.

MiVoice Business checks its database for the MAC address supplied by the phone.

If the MAC address is not in the database and the PIN is a null value, MiVoice Business responds with a PIN request. When the user enters the PIN for the set, the MiVoice Business checks its local database for the DN supplied within the PIN. For example, PIN ***6000 looks for DN 6000.

If the DN is in the database, the system registers the phone, maps the MAC address to the DN, and instructs the set to save the PIN in its memory.

If the DN is not in the database, as shown for DN 2004, MiVoice Business checks its Remote Directory Numbers form to determine if the DN is programmed on one of the other elements in the cluster. If it finds the DN, it locates the IP address of the DN’s element.

MiVoice Business tells the set to save its PIN and then sends the set a redirect message that contains the correct MiVoice Business IP address. The set then, without user intervention, attempts registration with the second MiVoice Business system, supplying its MAC address and PIN. Because the set now knows its PIN, the user is not prompted for a PIN when the set begins this new registration process at the new MiVoice Business system.

If the set supplied the PIN, and the PIN’s DN is already assigned to another MAC address, MiVoice Business tells the set to clear its PIN and prompt for a new PIN.

To reset a phone and have it use a new DN, press the * key during power up, then enter a new PIN when prompted.

If you delete an IP phone's DN or MAC address from the Multiline IP Sets form while the set is still connected, the PIN in the set will be cleared and the set will do a hard reset. MiVoice Business prompts for a new PIN.

If an invalid access code is entered as part of the PIN, the IP phone will prompt again for a PIN.

If the PIN stored in the IP Phone has a different Registration or Replacement Access Code from the one in the system database, the IP phone will prompt for a PIN.

NOTE: IP address reservations must also be made for IP Console applications(MiVoice Business Console) and the 5485 IP Paging Unit because they do not store their PINs in memory.

Related Topics

- Required Software and Options

- Feature Access Codes and RDNs