Cisco Unified SIP Phone 3905 Administration Guide for Cisco Unified Communications Manager 8.6 (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.

This chapter focuses on the interactions between the Cisco Unified SIP Phone 3905 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/​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 Phone and other key components of the Voice over IP (VoIP) network. It includes the following topics:

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.

Cisco Unified IP Phone and Cisco Unified Communications Manager Interaction

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 via 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 IP Phone Configuration" chapter in the Cisco Unified 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:/​/​tools.cisco.com/​support/​downloads/​go/​Redirect.x?mdfid=278875240



Note


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


Cisco Unified SIP Phone 3905 and VLAN Interaction

The Cisco Unified SIP Phone 3905 has 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 Voice-over-IP 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 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 Information

Cisco Unified IP Phone Power

The Cisco Unified SIP Phone 3905 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.


Power Guidelines

The following table provides guidelines for powering the Cisco Unified SIP Phone 3905.

Table 1 Guidelines for Powering the Cisco Unified SIP Phone 3905

Power Type

Guidelines

External power: Provided through the Cisco Unified SIP Phone 3905 Power Adapter.

The Cisco Unified SIP Phone 3905 uses the Cisco Unified SIP Phone 3905 Power Adapter.

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 100m 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 SIP Phone 3905 supports IEEE 802.3af Class 1 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 documentation for your switch 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 SIP Phone 3905.

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

Configuration Files

Configuration files for a phone 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.

If you configure security-related settings in Cisco Unified Communications Manager Administration, the phone configuration file will contain sensitive information. To ensure the privacy of a configuration file, you must configure it for encryption. For more 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 from the TFTP server when the following conditions exist:

  • You have enabled auto-registration 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

If auto registration is not enabled and the phone has not been added to the Cisco Unified Communications Manager database, the phone registration request will be rejected.

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

Phone Startup Process

When connecting to the VoIP network, the Cisco Unified SIP Phone 3905 go through a standard startup process that is described in the following table. Depending on your specific network configuration, 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   Configure the 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 Configuration Menus and Startup Problems.

    Step 3   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 Configuration Menus and Startup Problems.

    Step 4   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 Configuration Menus and Startup Problems.

    Step 5   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.

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

    Step 6   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 its software and hardware.

    For more information, see Startup Problems.

    Step 7   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 auto-registration is enabled in Cisco Unified Communications Manager, the phone attempts to auto-register 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 on licensing, see the "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

    Auto-registration

    No

    • Results in automatic assignment of directory numbers
    • Not available when security or encryption is enabled.

    Auto-registration with TAPS

    No

    Requires auto-registration 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

    By enabling auto-registration 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 Communications Manager database when you physically connect the phone to your IP telephony network. During auto-registration, 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 auto-registered phones to new locations and assign them to different device pools without affecting their directory numbers.

    Note


    Cisco recommends you use auto-registration to add less than 100 phones to your network. To add more than 100 phones to your network, use the Bulk Administration Tool (BAT).


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

    Autoregistration and TAPS Phone Addition

    You can add phones with auto-registration 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 pre-defined configurations for phones.


    Note


    Cisco recommends you use auto-registration 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, you or the end user dial a TAPS directory number and follow voice prompts. When the process is complete, the phone will have downloaded its directory number and other settings, and the phone will be updated in Cisco Unified Communications Manager Administration with the correct MAC address.

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

    For more information, see the "Bulk Administration" chapter in Cisco Unified Communications Manager 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, go to the "Cisco Unified Communications Manager Overview" chapter in the Cisco Unified Communications Manager System Guide.

    Add Phones using BAT Phone Template

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

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

    For detailed instructions about adding phones using the Bulk Administration menu, see the Cisco Unified Communications Manager Bulk Administration Guide, chapter " Inserting Phones".

    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 like Device Pool, Phone Button Template, and 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 existing BAT phone template.

      MAC Address for Cisco Unified IP Phone 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's MAC address in these ways:

      • From the phone, press Applications, 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 click the Device Information hyperlink.
      Related Tasks