Cisco Unified IP Phone 8941 and 8945 Administration Guide for Cisco Unified Communications Manager 9.0 (SCCP and SIP)
Cisco Unified IP Phone and Your Network
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Cisco Unified IP Phone and Your Network

Cisco Unified IP Phone and Your Network

Cisco Unified IP Phones enable you to communicate by using voice over a data network. To provide this capability, the IP Phones depend upon and interact with several other key Cisco Unified IP Telephony components, including Cisco Unified Communications Manager (Cisco Unified CM).

This chapter focuses on the interactions between the Cisco Unified IP Phone 8941 and 8945 and Cisco Unified Communications Manager, DNS and DHCP servers, TFTP servers, and switches. It also describes options for powering phones.

For related information about voice and IP communications, refer to this URL:

http:/​/​www.cisco.com/​en/​US/​products/​sw/​voicesw/​index.html

This chapter contains the following information:

Cisco Unified IP Communications Product Interactions

To function in the IP telephony network, the Cisco Unified IP Phone must be connected to a networking device, such as a Cisco Catalyst switch. You must also register the Cisco Unified IP Phone with a Cisco Unified Communications Manager system before sending and receiving calls.

This section includes the following topics:

Cisco Unified IP Phone and Cisco Unified Communications Manager Interactions

Cisco Unified Communications Manager is an open and industry-standard call processing system. Cisco Unified Communications Manager software sets up and tears down calls between phones, integrating traditional PBX functionality with the corporate IP network. Cisco Unified Communications Manager manages the components of the IP telephony system: the phones, the access gateways, and the resources necessary for features such as call conferencing and route planning. Cisco Unified Communications Manager also provides:

  • Firmware for phones
  • Configuration file using TFTP service
  • Authentication and encryption (if configured for the telephony system)
  • Phone registration
  • Call preservation, so that a media session continues if signaling is lost between the primary Cisco Unified Communications Manager and a phone

For information about configuring Cisco Unified Communications Manager to work with the IP devices described in this chapter, go to the "Cisco Unified IP Phone Configuration" chapter in the Cisco Communications Manager Administration Guide.


Note


If the Cisco Unified IP Phone model that you want to configure does not appear in the Phone Type drop-down list in Cisco Unified Communications Manager Administration, go to the following URL and install the latest support patch for your version of Cisco Unified Communications Manager:

http:/​/​www.cisco.com/​kobayashi/​sw-center/​sw-voice.shtml

For more information, refer to "Software Upgrades" chapter in the Cisco Unified Communications Operating System Administration Guide.


Cisco Unified IP Phone and VLAN Interaction

The Cisco Unified IP Phone 8941 and 8945 have an internal Ethernet switch, enabling forwarding of packets to the phone, and to the access port and the network port on the back of the phone.

If a computer is connected to the access port, the computer and the phone share the same physical link to the switch and share the same port on the switch. This shared physical link has the following implications for the VLAN configuration on the network:

  • The current VLANs might be configured on an IP subnet basis. However, additional IP addresses might not be available to assign the phone to the same subnet as other devices connected to the same port.
  • Data traffic present on the VLAN supporting phones might reduce the quality of VoIP traffic.
  • Network security may indicate a need to isolate the VLAN voice traffic from the VLAN data traffic.

You can resolve these issues by isolating the voice traffic onto a separate VLAN. The switch port that the phone is connected to would be configured to have separate VLANs for carrying:

  • Voice traffic to and from the IP phone (auxiliary VLAN on the Cisco Catalyst 6000 series, for example)
  • Data traffic to and from the PC connected to the switch through the access port of the IP phone (native VLAN)

Isolating the phones on a separate, auxiliary VLAN increases the quality of the voice traffic and allows a large number of phones to be added to an existing network when there are not enough IP addresses for each phone.

For more information, refer to the documentation included with a Cisco switch. You can also access switch information at this URL:

http:/​/​cisco.com/​en/​US/​products/​hw/​switches/​index.html

Related Tasks
Related References

Cisco Unified IP Phone and Cisco Unified Communications Manager Express Interaction

When the Cisco Unified IP Phone works with the Cisco Unified Communications Manager Express (Unified CME), the phones must go into CME mode.

When a user invokes the conference feature, the tag allows the phone to use either a local or network hardware conference bridge.

The Cisco Unified IP Phones do not support the following actions:

Transfer

Only supported in the connected call transfer scenario.

Conference

Only supported in the connected call transfer scenario.

Join

Supported using the Conference button or Hookflash access.

Hold

Supported using the Hold button.

Barge

Not supported.

Direct Transfer

Not supported.

Select

Not supported.

The users cannot create conference and transfer calls across different lines.

Cisco Unified IP Phone power

The Cisco Unified IP Phone can be powered with external power or with Power over Ethernet (PoE). External power is provided through a separate power supply. PoE is provided by a switch through the Ethernet cable attached to a phone.


Note


When you install a phone that is powered with external power, connect the power supply to the phone and to a power outlet before you connect the Ethernet cable to the phone. When you remove a phone that is powered with external power, disconnect the Ethernet cable from the phone before you disconnect the power supply.


Related Information

Power Guidelines

The following table provides guidelines for powering the Cisco Unified IP Phone 8941 and 8945.

Table 1 Guidelines for Powering the Cisco Unified IP Phone 8941 and 8945

Power Type

Guidelines

External power: Provided through the CP-PWR-CUBE-3 external power supply.

The Cisco Unified IP Phone 8941 and 8945 use the CP-PWR-CUBE-3 power supply.

External power: Provided through the Cisco Unified IP Phone Power Injector.

The Cisco Unified IP Phone Power Injector may be used with any Cisco Unified IP Phone. Functioning as a midspan device, the injector delivers inline power to the attached phone. The Cisco Unified IP Phone Power Injector is connected between a switch port and the IP Phone, and supports a maximum cable length of 100 m between the unpowered switch and the IP Phone.

PoE power: Provided by a switch through the Ethernet cable attached to the phone.

The Cisco Unified IP Phone 8941 supports IEEE 802.3af Class 1 power on signal pairs and spare pairs.

The Cisco Unified IP Phone 8945 supports IEEE 802.3af Class 2 power on signal pairs and spare pairs.

To ensure uninterruptible operation of the phone, make sure that the switch has a backup power supply.

Make sure that the CatOS or IOS version running on your switch supports your intended phone deployment. Refer to the switch documentation for operating system version information.

External power: Provided through inline power patch panel WS-PWR-PANEL

The inline power patch panel WS-PWR-PANEL is compatible with the Cisco Unified IP Phone 8941 and 8945.

Power Outage

Your access to emergency service through the phone requires the phone to receive power. If an interruption in the power supply occurs, Service and Emergency Calling Service dialing do not function until power is restored. In the case of a power failure or disruption, you may need to reset or reconfigure equipment before you can use the Service or Emergency Calling Service dialing.

Additional Information About Power

The documents in the following table provide more information on the following topics:

  • Cisco switches that work with Cisco Unified IP Phones
  • Cisco IOS releases that support bidirectional power negotiation
  • Other requirements and restrictions about power

Phone Configuration Files

Phone configuration files are stored on the TFTP server and define parameters for connecting to Cisco Unified Communications Manager. In general, any time you make a change in Cisco Unified Communications Manager that requires the phone to be reset, a change is automatically made to the phone configuration file.

Configuration files also contain information about which image load the phone should be running. If this image load differs from the one currently loaded on a phone, the phone contacts the TFTP server to request the required load files.

A phone accesses a default configuration file named XmlDefault.cnf.xml from the TFTP server when the following conditions exist:

  • You have enabled autoregistration in Cisco Unified Communications Manager.
  • The phone has not been added to the Cisco Unified Communications Manager database.
  • The phone is registering for the first time.

In addition, if the device security mode in the configuration file is set to Authenticated and the CTL file on the phone has a valid certificate for Cisco Unified Communications Manager, the phone establishes a TLS connection to Cisco Unified Communications Manager. Otherwise, the phone establishes a TCP connection.


Note


If the device security mode in the configuration file is set to secure, but the phone has not received a CTL file, the phone tries four times to obtain a CTL file so it can register securely.



Note


Cisco Extension Mobility Cross Cluster is an exception, in that the phone permits a TLS connection to Cisco Unified Communications Manager for secure signaling even without the CTL file.


If you configure security-related settings in Cisco Unified Communications Manager Administration, the phone configuration file contains sensitive information. To ensure the privacy of a configuration file, you must configure it for encryption. For detailed information, see the "Configuring Encrypted Phone Configuration Files" chapter in Cisco Unified Communications Manager Security Guide. A phone requests a configuration file whenever it resets and registers with Cisco Unified Communications Manager.

A phone accesses a default configuration file named XmlDefault.cnf.xml only when the phone has not received a valid Trust List file containing a certificate assigned to the Cisco Unified Communications Manager and TFTP.

If autoregistration is not enabled and you did not add the phone to the Cisco Unified Communications Manager database, the phone does not attempt to register with Cisco Unified Communications Manager. The phone continually displays the Configuring IP message until you either enable autoregistration or add the phone to the Cisco Unified Communications Manager database.

If the phone has registered before, the phone accesses the configuration file named SEPmac_address.cnf.xml, where mac_address is the MAC address of the phone.

The filenames are derived from the MAC Address and Description fields in the Phone Configuration window of Cisco Unified Communications Manager Administration. The MAC address uniquely identifies the phone.

For more information on phone configuration settings, see the "Cisco Unified IP Phone Configuration" chapter in the Cisco Communications Manager Administration Guide.

For more information, see the Cisco Unified Communications Manager Security Guide.

Phone startup process

When connecting to the VoIP network, the Cisco Unified IP Phone goes through a standard startup process that is described in the following steps. Depending on your specific network setup, not all of these steps may occur on your Cisco Unified IP Phone.

Procedure
    Step 1   Obtain power from the switch.

    If a phone is not using external power, the switch provides in-line power through the Ethernet cable attached to the phone.

    For more information, see Cisco Unified Communications Manager Phone Addition Methods and Startup Problems.

    Step 2   Load the Stored Phone Image. The Cisco Unified IP Phone has nonvolatile flash memory in which it stores firmware images and user-defined preferences. At startup, the phone runs a bootstrap loader that loads a phone image stored in flash memory. Using this image, the phone initializes the software and hardware.

    For more information, see Startup Problems.

    Step 3   Configure VLAN.

    If the Cisco Unified IP Phone is connected to a Cisco Catalyst switch, the switch next informs the phone of the voice VLAN defined on the switch. The phone needs to know its VLAN membership before it can proceed with the Dynamic Host Configuration Protocol (DHCP) request for an IP address.

    For more information, see Network Setup Menu and Startup Problems.

    Step 4   Obtain an IP Address. If the Cisco Unified IP Phone is using DHCP to obtain an IP address, the phone queries the DHCP server to obtain one. If you are not using DHCP in your network, you must assign static IP addresses to each phone locally.

    For more information, see Network Setup Menu and Startup Problems.

    Step 5   Access a TFTP Server. In addition to assigning an IP address, the DHCP server directs the Cisco Unified IP Phone to a TFTP Server. If the phone has a statically defined IP address, you must configure the TFTP server locally on the phone; the phone then contacts the TFTP server directly.
    Note   

    You can also assign an alternative TFTP server to use instead of the one assigned by DHCP.

    For more information, see Network Setup Menu and Startup Problems.

    Step 6   Request the Certificate Trust List (CTL) file. The TFTP server stores the CTL file. The CTL file contains the certificates necessary for establishing a secure connection between the phone and Cisco Unified Communications Manager.

    For more information, see the Cisco Unified Communications Manager Security Guide, "Configuring the Cisco CTL Client" chapter.

    Step 7   Request the configuration file. The TFTP server has configuration files that define parameters for connecting to Cisco Unified Communications Manager and other information for the phone.

    For more information, see Cisco Unified Communications Manager Phone Addition Methods and Startup Problems.

    Step 8   Contact Cisco Unified Communications Manager.

    The configuration file defines how the Cisco Unified IP Phone communicates with Cisco Unified Communications Manager and provides a phone with its load ID. After obtaining the file from the TFTP server, the phone attempts to make a connection to the highest priority Cisco Unified Communications Manager on the list.

    If the phone was manually added to the database, Cisco Unified Communications Manager identifies the phone. If the phone was not manually added to the database and autoregistration is enabled in Cisco Unified Communications Manager, the phone attempts to autoregister itself in the Cisco Unified Communications Manager database.

    For more information, see Startup Problems.


    Cisco Unified Communications Manager Phone Addition Methods

    Before installing the Cisco Unified IP Phone, you must choose a method for adding phones to the Cisco Unified Communications Manager database. Be aware that each phone type requires a fixed number of device license units and the number of unit licenses that are available on the server may impact phone registration. For more information about licensing, see "Licenses for Phones" section in the Cisco Unified Communications Manager System Guide.

    The following table provides an overview of these methods for adding phones to the Cisco Unified Communications Manager database.

    Table 2 Methods for adding phones to the Cisco Unified Communications Manager database

    Method

    Requires MAC address?

    Notes

    Autoregistration

    No

    Results in automatic assignment of directory numbers

    Not available when security or encryption is enabled

    Note   

    Autoregistration is disabled when security is enabled on Cisco Unified Communications Manager. In this case, the phone must be manually added to the Cisco Unified Communications Manager database.

    Autoregistration with TAPS

    No

    Requires autoregistration and the Bulk Administration Tool (BAT); updates information in the Cisco Unified IP Phone and in Cisco Unified Communications Manager Administration

    Using the Cisco Unified Communications Manager Administration

    Yes

    Requires phones to be added individually

    Using BAT

    Yes

    Allows for simultaneous registration of multiple phones

    Autoregistration Phone Addition

    If you enable autoregistration before you begin installing phones, you can:

    • Add phones without first gathering MAC addresses from the phones.
    • Automatically add a Cisco Unified IP Phone to the Cisco Unified CM database when you physically connect the phone to your IP telephony network. During autoregistration, Cisco Unified Communications Manager assigns the next available sequential directory number to the phone.
    • Quickly enter phones into the Cisco Unified Communications Manager database and modify any settings, such as the directory numbers, from Cisco Unified Communications Manager.
    • Move autoregistered phones to new locations and assign them to different device pools without affecting their directory numbers.

    Note


    Cisco recommends that you use autoregistration to add fewer than 100 phones to your network. To add more than 100 phones to your network, use the Bulk Administration Tool (BAT).


    Autoregistration is disabled by default. In some cases, you might not want to use autoregistration; for example, if you want to assign a specific directory number to the phone. For information about enabling autoregistration, see "Enable autoregistration" section in the Cisco Unified Communications Manager Administration Guide.


    Note


    When you configure the cluster for mixed mode through the Cisco CTL client, autoregistration is automatically disabled. When you configure the cluster for nonsecure mode through the Cisco CTL client, autoregistration is automatically enabled.


    Autoregistration and TAPS Phone Addition

    You can add phones with autoregistration and TAPS, the Tool for Auto-Registered Phones Support, without first gathering MAC addresses from phones.

    TAPS works with the Bulk Administration Tool (BAT) to update a batch of phones that were already added to the Cisco Unified Communications Manager database with dummy MAC addresses. Use TAPS to update MAC addresses and download predefined configurations for phones.


    Note


    Cisco recommends that you use autoregistration and TAPS to add less than 100 phones to your network. To add more than 100 phones to your network, use the Bulk Administration Tool (BAT).


    To implement TAPS, dial a TAPS directory number and follow the voice prompts. When the process completes, the phone has downloaded the directory number and other settings, and the phone is updated in Cisco Unified Communications Manager Administration with the correct MAC address.

    Autoregistration must be enabled in Cisco Unified Communications Manager Administration (System > Cisco Unified CM) for TAPS to function.


    Note


    When you configure the cluster for mixed mode through the Cisco CTL client, autoregistration is automatically disabled. When you configure the cluster for nonsecure mode through the Cisco CTL client, autoregistration is automatically enabled.


    For more information, see "Bulk Administration" chapter in the Cisco Unified Communications Manager Administration Guide and the "Tool for Auto-Registered Phones Support" chapter in the Cisco Unified Communications Manager Bulk Administration Guide.

    Cisco Unified Communications Manager Administration Phone Addition

    You can add phones individually to the Cisco Unified Communications Manager database by using Cisco Unified Communications Manager Administration. To do so, you first need to obtain the MAC address for each phone.

    After you have collected MAC addresses, in Cisco Unified Communications Manager Administration, choose Device > Phone and click Add New to begin.

    For complete instructions and conceptual information about Cisco Unified Communications Manager, see the "Cisco Unified Communications Manager Overview" chapter in the Cisco Unified Communications Manager System Guide.

    BAT Phone Addition

    Cisco Unified Communications Manager Bulk Administration Tool (BAT) enables you to perform batch operations, including registration, on multiple phones. To access BAT, choose the Bulk Administration drop-down menu in Cisco Unified Communications Manager Administration.

    To add phones using BAT only (not in conjunction with TAPS), you can use the MAC address for each phone or dummy MAC addresses if you have a large number of new phones.

    For detailed instructions about using BAT, see the Bulk Administration chapter in the Cisco Unified Communications Manager Administration Guide.

    Cisco Unified IP Phone MAC Address Determination

    Several procedures described in this manual require you to determine the MAC address of a Cisco Unified IP Phone. You can determine the MAC address of a phone in these ways:

    • From the phone, press the Applications button, select Phone Information and look at the MAC Address field.
    • Look at the MAC label on the back of the phone.
    • Display the web page for the phone and select Device Information. For information about accessing the web page, see the "Accessing the Web Page for a Phone" section of this document.