Cisco Unified IP Phone 7941G, 7941G-GE, 7942G, 7961G, 7961G-GE, and 7962G Administration Guide for Cisco Unified Communications Manager 9.0 (SCCP and SIP)
Cisco Unified IP Phones and Your Network
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Cisco Unified IP Phones and Your Network

Contents

Cisco Unified IP Phones and Your Network

Phone and Network Overview

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

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

For related information about voice and IP communications, see:

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

This chapter provides an overview of the interaction between the Cisco Unified IP Phones and other key components of the Voice over IP (VoIP) network.

Cisco Unified Communications Product Interactions

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

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
  • Authentication and encryption (if configured for the telephony system)
  • Configuration, certificate trust list (CTL), and Identity Trust List (ITL) files via the TFTP service
  • Phone registration
  • Call preservation, so that a media session continues if signaling is lost between the primary Communications Manager and a phone

For information about configuring Cisco Unified Communications Manager to work with the IP devices described in this chapter, see the Cisco Unified Communications Manager Administration Guide, Cisco Unified Communications Manager System Guide, and Cisco Unified Communications Manager Security 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


Cisco Unified IP Phones and VLAN Interaction

The Cisco Unified IP Phones 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 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 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 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 where 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 Power

The Cisco Unified IP Phones 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.


The following sections provide more information about powering a phone.

Power Guidelines

The following table provides guidelines for powering the Cisco Unified IP Phones.

Table 1 Power Guidelines for the Cisco Unified IP Phones

Power type

Guidelines

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

The Cisco Unified IP Phones 7941G, 7942G, 7961G, and 7962G use the CP-PWR-CUBE-3 power supply

The Cisco Unified IP Phones 7941G-GE and 7961G-GE use the CP-PWR-CUBE-3 external power supply only.

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 Phones 7962G, 7942G, 7961G, and 7941G support Cisco inline PoE, but the Cisco Unified IP Phones 7961G-GE, and 7941G-GE do not.

The Cisco Unified IP Phones 7962G and 7942G support IEEE 802.3af Class 2 power on signal pairs and spare pairs. The Cisco Unified IP Phones 7961G-GE, and 7941G-GE are not compatible with Cisco switches that are not IEEE compliant.

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 documentation for your switch for operating system version information.

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

For related information about power, refer to the documents shown in the following table. These documents provide information about the following topics:

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

Phone Configuration Files

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

Configuration files also contain information about the image load that the phone should be running. If this image load differs from the one currently that is loaded on a phone currently, the phone contacts the TFTP server to request the required load files. These load files are digitally signed to ensure the authenticity of the file source.

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. For SIP phones, a TLS connection requires that the transport protocol in the phone configuration file be set to TLS, which corresponds to the transport type in the SIP Security Profile in Cisco Unified Communications Manager Administration.


Note


If the device security mode in the configuration file is set to Authenticated or Encrypted but the phone has not received a CTL or ITL file, the phone tries four times to obtain the 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 more information, see the Cisco Unified Communications Manager Security Guide, "Configuring Encrypted Phone Configuration Files" chapter.

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 that contains a certificate assigned to 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 system rejects the phone registration request with Cisco Unified Communications Manager. The phone displays the Configuring IP message continuously until you either enable autoregistration or add the phone to the Cisco Unified Communications Manager database.

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

For SIP phones, the TFTP server generates these SIP configuration files:

  • SIP IP Phone
    • For unsigned and unencrypted files: SEP<mac>.cnf.xml
    • For signed files: SEP<mac>.cnf.xml.sgn
    • For signed and encrypted files: SEP<mac>.cnf.xml.enc.sgn
  • Dial Plan: <dialplan>.xml
  • Softkey Template: <softkey_template>.xml

The filenames derive from the MAC Address and Description fields in the Phone Configuration window of Cisco Unified Communications Manager. The MAC address uniquely identifies the phone. For more information, see the Cisco Unified Communications Manager Administration Guide.

For more information about the phone interaction with the TFTP server, see the Cisco Unified Communications Manager System Guide, "Cisco TFTP" chapter.

Phone Startup Process

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

Procedure
    Step 1   Obtain ower 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.

    Step 2   Load the stored phone image

    The Cisco Unified IP Phone has non-volatile 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 nonvolatile flash. Using this image, the phone initializes its software and hardware.

    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.

    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 your network does not use DHCP, you must assign static IP addresses to each phone locally.

    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.

    Step 6   Request the CTL file

    The TFTP server stores the certificate trust list (CTL) file. This file contains the certificates necessary for establishing a secure connection between the phone and Cisco Unified Communications Manager.

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

    Step 7   Request the ITL file.

    The phone requests the ITL file after it requests the CTL file. The ITL file contains the certificates of the entities that the phone can trust. The certificates are used for authenticating a secure connection with the servers or authenticating a digital signature signed by the servers.

    For more information, see Cisco Unified Communications Manager Security Guide, “Security by Default” chapter.

    Step 8   Request the configuration file

    The TFTP server has configuration files, which define parameters for connecting to Cisco Unified Communications Manager and other information for the phone.

    Step 9   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. When security is implemented, if the security profile of the phone is configured for secure signaling (encrypted or authenticated), and the Cisco Unified Communications Manager is set to secure mode, the phone makes a TLS connection. Otherwise, it makes a nonsecure TCP connection.

    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 auto-registration is enabled in Cisco Unified Communications Manager, the phone attempts to auto-register itself in the Cisco Unified Communications Manager database.

    Note   

    Autoregistration is disabled when you configure the CTL client. In this case, the phone must be manually added to the Cisco Unified Communications Manager database.


    Related Information

    Cisco Unified Communications Manager Phone Addition Methods

    Before installing the Cisco Unified IP Phones, you must choose a method for adding phones to the Cisco Unified Communications Manager database.

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

    Table 2 Phone Addition Methods in 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

    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

    Related Tasks

    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 Cisco Unified Communications Manager Administration Guide and Cisco Unified Communications Manager System Guide.

    Add Phones with BAT

    Cisco Unified Communications Manager Bulk Administration Tool (BAT), a standard Cisco Unified Communications Manager application, enables you to perform batch operations, including registration, on multiple phones.

    To add phones using BAT only (not in conjunction with TAPS), you first need to obtain the appropriate MAC address for each phone.

    To add a phone to the Cisco Unified Communications Manager, follow these steps:

    Procedure
      Step 1   From Cisco Unified Communications Manager, choose Bulk Administration > Phones > Phone Template.
      Step 2   Click Add New.
      Step 3   Choose a Phone Type and click Next.
      Step 4   Enter the details of phone specific parameters such as Device Pool, Phone Button Template, Device Security Profile.
      Step 5   Click Save.
      Step 6   From Cisco Unified Communications Manager, choose Device > Phone > Add New to add a phone using an already created BAT phone template.

      For more information on BAT, see Cisco Unified Communications Manager Bulk Administration Guide. For more information on creating BAT Phone Templates, see Cisco Unified Communications Manager Bulk Administration Guide, “Phone Template” chapter.


      Cisco Unified IP Phones and Different Protocols

      The Cisco Unified IP Phones can operate with Skinny Client Control Protocol (SCCP) or Session Initiation Protocol (SIP). You can convert a phone from using one protocol to using the other protocol.

      Convert New Phone from SCCP to SIP

      A new, unused phone is set for SCCP by default. To convert this phone to SIP, perform these steps:

      Procedure
        Step 1   Take one of these actions:
        • To autoregister the phone, set the Auto Registration Phone Protocol enterprise parameter in Cisco Unified Communications Manager Administration to SIP.
        • To provision the phone by using the Bulk Administration Tool (BAT), choose the appropriate phone model and choose SIP from BAT.
        • To provision the phone manually, make the appropriate changes for SIP on the Phone Configuration window in Cisco Unified Communications Manager Administration.

        For more information on Cisco Unified Communications Manager configuration, see Cisco Unified Communications Manager Administration Guide. For more information on using BAT, see Cisco Unified Communications Manager Bulk Administration Guide.

        Step 2   If you are not using DHCP in your network, configure the network parameters for the phone.
        Step 3   Save the configuration updates, click Apply Config, click OK in the Apply Configuration Information window, and have the user power cycle the phone.

        Related Information

        In-Use Phone Protocol to Protocol Conversion

        For information on how to convert an in-use phone from one protocol to the other, see the Cisco Unified Communications Manager Administration Guide, "Cisco Unified IP Phone Configuration" chapter, "Migrate existing phone settings to another phone" section.

        Deploy Phone in SCCP and SIP Environment

        To deploy Cisco Unified IP Phones in an environment that includes SCCP and SIP and in which the Cisco Unified Communications Manager autoregistration parameter specifies SCCP, perform these general steps:

        Procedure
          Step 1   Set the Cisco Unified Communications Manager auto_registration_protocol parameter to SCCP.
          Step 2   From Cisco Unified Communications Manager, choose System > Enterprise Parameters.
          Step 3   Install the phones.
          Step 4   Change the Auto Registration Protocol enterprise parameter to SIP.
          Step 5   Autoregister the SIP phones.

          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 a phone MAC address in these ways:

          • From the phone, press the Settings button, select Model 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 click the Device Information hyperlink.

          Access Web Page for Phone.