Administration Guide for Cisco IP Communicator Release 2.1

Overview of Cisco IP Communicator

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•Overview of Cisco IP Communicator Features

•Supported Networking Protocols

•How Cisco IP Communicator Interacts with Cisco Unified Communications Manager

•How Cisco IP Communicator Interacts With the Network at Startup

•About Configuration Files

•QoS Modifications to Prioritize Voice Traffic

Overview of Cisco IP Communicator Features

Cisco IP Communicator is a software-based application that allows users to place and receive phone calls by using their personal computers. Cisco IP Communicator depends upon the Cisco Unified Communications Manager call-processing system (formerly known as Cisco Unified CallManager) to provide telephony features and voice-over-IP capabilities through eight telephone lines (or a combination of lines, softkeys, and direct access to telephony features).

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Note Depending on context, this guide refers to Cisco IP Communicator as a phone, device, application, or an interface.

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When registered to Cisco Unified Communications Manager, Cisco IP Communicator has the capabilities of a full-featured Cisco Unified IP Phone, including the ability to transfer calls, forward calls, and conference additional participants to an existing call. This means that you can provision and upgrade Cisco IP Communicator as any other Cisco Unified IP Phone, greatly simplifying IP phone management. Through automatic software updates, Cisco IP Communicator keeps pace with new software features and changes.

Cisco IP Communicator enables you to deliver Extensible Markup Language (XML)-based applications to the display and provide quick access to diverse information such as weather, stocks, quote of the day, or any other web-based information.

Cisco IP Communicator offers high-quality audio features such as the Audio Tuning Wizard, an advanced (adaptive) jitter buffer and packet loss (error) concealment, acoustic echo cancellation, noise suppression, voice activity detection, and silence suppression.

Cisco IP Communicator offers other advanced features that accommodate ever-mobile users and changing network conditions. These features include auto-detection of Cisco VPN clients, automated support for most VPN clients (including Microsoft PPTP client), interoperability with Cisco Unified Video Advantage for desktop video calls, and non-MAC-based device name for easy PC refreshes (requires Cisco Unified Communications Manager Release 5.x or later).

In Release 2.1(1), Cisco IP Communicator offers support for Session Initiation Protocol (SIP) signaling, security features (device and signaling authentication), and support for the Cisco Unified IP Phone 7970 8.0(4) firmware code base.

For details about configuring Cisco IP Communicator for different protocols, for security features, and for details about supported call features, see the Related Topics section.

For details about the all Cisco IP Communicator features, see the data sheet at this URL:

http://www.cisco.com/en/US/products/sw/voicesw/ps5475/products_data_sheet09186a00801f8e48.html

For details about using the application, see the user guide at this URL:

http://www.cisco.com/en/US/products/sw/voicesw/ps5475/products_user_guide_list.html

Related Topics

•How to Configure Cisco IP Communicator with Different Protocols

•How to Configure Security Features for Cisco IP Communicator

•Telephony Features Available for Cisco IP Communicator

Supported Networking Protocols

Table 1-1 lists the industry-standard and Cisco networking protocols required for voice communication Use this information to help you design your network.

Table 1-1 Supported Networking Protocols 

Networking Protocol	Purpose	Usage Notes
BootP1	Enables a network device such as Cisco IP Communicator to discover certain startup information, such as its IP address.	If you are using BootP to assign IP addresses to Cisco IP Communicator, the BOOTP Server option shows "Yes" in the network configuration settings on the phone.
CDP2	Device-discovery protocol that runs on all Cisco-manufactured equipment. By using CDP, a device can advertise its existence to other devices and receive information about other devices in the network.	Cisco IP Communicator uses CDP to communicate information such as auxiliary VLAN ID, per-port power management details, and QoS3 configuration information with the Cisco Catalyst switch.
DHCP	Dynamically allocates and assigns an IP address to network devices. DHCP enables you to connect Cisco IP Communicator into the network and have it become operational without you manually assigning an IP address or configuring additional network parameters.	We recommend that you use DHCP custom option 150. With this method, you configure the TFTP server IP address as the option value. For additional supported DCHP configurations, see the Cisco Unified Communications Manager System Guide at this URL: http://www.cisco.com/en/US/products/sw/voicesw/ps556/prod_maintenance_guides_list.html
HTTP4	Uses TCP to transfer web content over the Internet.	Cisco IP Communicator uses HTTP to obtain the configuration file, LDAP directories configuration, dialing rules, XML services, and locale strings.
IP	Messaging protocol that addresses and sends packets across the network.	To communicate by using IP, network devices must have an assigned IP address, subnet, and gateway. Cisco IP Communicator obtains its IP information from the system network configuration.
LDAP	Protocol for accessing directories.	Cisco IP Communicator can use LDAP to search for names and phone numbers.
RTP5	Standard protocol for transporting real-time data, such as interactive voice and video, over data networks.	Cisco IP Communicator uses the RTP to receive from and send real-time voice traffic to other Cisco IP Communicators and gateways.
SDP6	Portion of the SIP protocol that determines which parameters are available during a connection between two endpoints. Conferences are established by using only the SDP capabilities that are supported by all endpoints in the conference.	SDP capabilities (such as codec types, DTMF detection, and comfort noise) are normally configured on a global basis by Cisco Unified Communications Manager or the Media Gateway in operation. Some SIP endpoints might allow these parameters to be configured on the endpoint. This might vary from vendor to vendor.
SCCP7	Includes a messaging set that allows communications between call control servers and endpoint clients such as IP Phones. SCCP is proprietary to Cisco Systems.	Cisco IP Communicator to can use either SCCP or SIP.
SIP8	Standard for setting up telephone calls, multimedia conferencing, and other types of communications on the Internet. SIP can be used to establish, maintain, and terminate calls between two or more endpoints. SIP provides signaling, which allows call information to be carried across network boundaries. SIP provides session management, which controls the attributes of an end-to-end call.	Cisco IP Communicator to can use either SCCP or SIP.
TCP	Connection-oriented transport protocol.	Cisco IP Communicator uses TCP to connect to Cisco Unified Communications Manager and to access XML services.
TFTP	Allows you to transfer files over the network. On Cisco IP Communicator, TFTP enables you to obtain a configuration file specific to the phone type.	TFTP requires a TFTP server in your network, which can be automatically identified from the DHCP server. If you want Cisco IP Communicator to use a TFTP server other than the one specified by the DHCP server, you must manually assign the TFTP server in Cisco IP Communicator.
TLS9	Standard protocol for securing and authenticating communications.	When security is implemented, Cisco IP Communicator uses the TLS protocol when securely registering with Cisco Unified Communications Manager.
UDP10	Connectionless messaging protocol for delivery of data packets.	Cisco IP Communicator transmits and receives RTP streams, which uses UDP.
XML	Markup language for documents containing structured information.	Cisco IP Communicator can access Cisco XML web services.

1 BOOTP = Bootstrap Protocol 2 CDP = Cisco Discovery Protocol 3 QoS = quality of service 4 HTTP = HyperText Transfer Protocol 5 RTP = Real-Time Transport Protocol 6 SDP = Session Description Protocol 7 SCCP = Skinny Client Control Protocol 8 SIP = Session Initiation Protocol 9 TLS = Transport Layer Security 10 UDP = User Datagram Protocol

Related Topics

•How Cisco IP Communicator Interacts with Cisco Unified Communications Manager

•How Cisco IP Communicator Interacts With the Network at Startup

How Cisco IP Communicator Interacts with Cisco Unified Communications Manager

Cisco IP Communicator is a software application that enables you to communicate by using voice over a data network. To provide this capability, Cisco IP Communicator depends upon Cisco Unified Communications Manager to set up and tear down calls between phone devices, integrating traditional PBX functionality with the corporate IP network. Cisco Unified Communications Manager manages all components of the IP telephony system—the phone devices, access gateways, and the resources necessary for such features as conference calls and route plans. Cisco Unified Communications Manager also provides:

•Firmware for phones

•Authentication (if configured for the telephony system)

•Device configuration file and certificate trust list (CTL) file through the TFTP service

•Cisco IP Communicator registration

•Call preservation so that a media session continues if signaling is lost between the primary Cisco Unified Communications Manager and Cisco IP Communicator

As you would do with other Cisco Unified IP Phones that rely on Cisco Unified Communications Manager, you must configure and manage Cisco IP Communicator as a network device through Cisco Unified Communications Manager Administration. For details, see Cisco Unified Communications Manager Administration Guide and Cisco Unified Communications Manager System Guide at this URL:

http://www.cisco.com/en/US/products/sw/voicesw/ps556/prod_maintenance_guides_list.html

For details about supported Cisco Unified Communications Manager releases, see the Cisco IP Communicator release notes at this URL:

http://www.cisco.com/en/US/products/sw/voicesw/ps5475/prod_release_notes_list.html

Related Topics

•How Cisco IP Communicator Interacts With the Network at Startup

•About Configuration Files

•QoS Modifications to Prioritize Voice Traffic

•Network, Server, and Client PC Requirements

•Telephony Features Available for Cisco IP Communicator

How Cisco IP Communicator Interacts With the Network at Startup

At startup, Cisco IP Communicator interacts with the network as follows:

1. Locates the configuration server.

Upon startup, Cisco IP Communicator always attempts to use DHCP to locate its TFTP server. Cisco IP Communicator first tries to use HTTP (by default) to retrieve files from the server, and if it is not able, Cisco IP Communicator uses TFTP.

If you used the Cisco IP Communicator Administration Tool, Cisco IP Communicator can also use HTTP to retrieve software updates, thereby accelerating file transfer for remote users. This tool is for Windows-based Cisco Unified Communications Managers only. Obtain the tool from the product software download web site: http://tools.cisco.com/support/downloads/pub/Redirect.x?mdfid=278468661.

It is located inside the zipped folder with your build.

If you do not use DHCP in your network to identify TFTP servers, or if you want the device to use an alternate TFTP server, you must manually configure your TFTP server from Cisco IP Communicator or instruct users to do this task.

2. Requests the CTL file (if security is configured).

The TFTP server stores the CTL file, which contains a list of Cisco Unified Communications Managers and TFTP servers that Cisco IP Communicator is authorized to connect to. It also contains the certificates necessary for establishing a secure connection between Cisco IP Communicator and Cisco Unified Communications Manager.

The security CTLFile.tlv file is downloaded to the [ApplicationData]\Cisco\Communicator\sec folder.

3. Requests configuration files.

Configuration files (.cnf.xml) reside 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 a device to be reset, a change is made to the configuration file for that device.

–If you have enabled auto-registration in Cisco Unified Communications Manager, Cisco IP Communicator accesses a default configuration file (xmldefault.cnf.xml) from the TFTP server.

–Otherwise, Cisco IP Communicator accesses a .cnf.xml file corresponding to its device name.

4. Downloads locale strings.

The.cnf.xml file configuration file tells Cisco IP Communicator which user locale strings to use. To make this request, Cisco IP Communicator first tries to use HTTP. If you have not enabled HTTP access, Cisco IP Communicator uses TFTP.

5. Contacts Cisco Unified Communications Manager.

After obtaining the configuration file from the TFTP server, Cisco IP Communicator attempts to make a connection to the highest priority Cisco Unified Communications Manager on the list. If security is implemented, Cisco IP Communicator makes a TLS connection; otherwise, it makes a nonsecure TCP connection.

–If the device was added to the database individually (through Cisco Unified Communications Manager Administration or in bulk through the Bulk Administration Tool (BAT), Cisco Unified Communications Manager identifies the device. This is only true if you are not using BAT with the Tool for Auto-Registered Phones Support (TAPS).

–Otherwise, the device attempts to register itself in the Cisco Unified Communications Manager database (when auto-registration is enabled in Cisco Unified Communications Manager).

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Note Auto-registration is disabled when security is enabled on Cisco Unified Communications Manager. In this case, you must manually add Cisco IP Communicator to the Cisco Unified Communications Manager database.

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Related Topics

•About Configuration Files

•About Methods for Adding Devices to the Cisco Unified Communications Manager Database

•How to Configure Cisco IP Communicator with Different Protocols

•How to Configure Security Features for Cisco IP Communicator

•About Specifying a TFTP Server

•About Updating the Application

•How to Resolve Startup Problems

About Configuration Files

Configuration files for Cisco IP Communicator 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 Cisco IP Communicator to be reset, a change is automatically made to the configuration file on Cisco IP Communicator.

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

In addition, if the device security mode in the configuration file is set to Authenticated and the CTL file on Cisco IP Communicator has a valid certificate for Cisco Unified Communications Manager, Cisco IP Communicator establishes a TLS connection to Cisco Unified Communications Manager. Otherwise, Cisco IP Communicator establishes a TCP connection. The transport protocol in the configuration file must also be set to TLS (corresponding to the transport type in the SIP Security Profile on Cisco Unified Communications Manager).

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Note If the device security mode in the configuration file is set to Authenticated, but Cisco IP Communicator has not received a CTL file, Cisco IP Communicator continuously tries to obtain a CTL file so that it can register securely.

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Related Topics

•Cisco IP Communicator Requests for Configuration Files

•Configuration Files Stored on the TFTP Server

Cisco IP Communicator Requests for Configuration Files

Cisco IP Communicator requests a configuration file whenever it resets and registers with Cisco Unified Communications Manager.

If auto-registration is not enabled and Cisco IP Communicator has not been added to the Cisco Unified Communications Manager database, the registration request is rejected. In this case, Cisco IP Communicator resets and repeatedly attempts to register.

If this installation of Cisco IP Communicator has registered before, Cisco IP Communicator accesses the configuration file named device_name.cnf.xml, where device_name is the user-defined device name for this instance of Cisco IP Communicator.

Related Topics

•About Configuration Files

•Configuration Files Stored on the TFTP Server

Configuration Files Stored on the TFTP Server

The TFTP server provides these configuration files for SIP and SCCP devices:

•IP Phones:

–For unsigned and unencrypted files—device_name.cnf.xml

–For signed files—device_name.cnf.xml.sgn

–For signed and encrypted files—device_name.cnf.xml.enc.sgn

•Dial Plan—dialplan.xml

You must configure and associate dial plans with a phone device to enable dial plans to be sent to the configuration file. If you do not configure a phone dial plan, Cisco IP Communicator does not display any indication of a dial plan.

You configure SIP dial rules from the SIP Dial Rule Configuration window (Call Routing > Dial Rules > SIP Dial Rules) in Cisco Unified Communications Manager Administration.

You configure SCCP dial rules from the Application Dial Rules Configuration window (Call Routing > Dial Rules > Application Dial Rules) in Cisco Unified Communications Manager Administration.

For details about configuring dial rules, see the Cisco Unified Communications Manager Administration Guide at this URL:

http://www.cisco.com/en/US/products/sw/voicesw/ps556/prod_maintenance_guides_list.html

•Softkey Template—softkey_template.xml

The filenames are derived from the devicename field in the Cisco Unified Communications Manager database. The devicename uniquely identifies a particular Cisco IP Communicator installation.

Related Topics

•How Cisco IP Communicator Interacts With the Network at Startup

QoS Modifications to Prioritize Voice Traffic

Voice quality can be compromised on an IP device by data traffic. Because Cisco IP Communicator is a software-based phone instead of a hardware phone, you cannot solve this problem by isolating voice-over-IP traffic to an auxiliary VLAN. Instead, you must modify QoS parameters in the network so that voice data traffic is prioritized over generic data traffic.

For details about configuring QoS in your network:

Cisco Unified Communications SRND based on Cisco Unified Communications Manager

http://www.cisco.com/en/US/products/sw/voicesw/ps556/products_implementation_design_guides_list.html

Differentiated Services Code Point (DSCP) Markings

The Vista Enterprise Operating System does not support setting DSCP markings. Vista Business and Vista Ultimate Operating Systems only support DSCP marking on wired network interfaces.

We recommend that you prioritize voice traffic on the network level rather than on an individual user system. DSCP markings can be re-tagged by the QoS Packet Scheduler at the network interface level on the end-user's system. DSCP markings can also be re-tagged by a switch in the network after Cisco IP Communicator tags it based on the Cisco Unified Communications Manager settings.

Related Topics

•How Cisco IP Communicator Interacts with Cisco Unified Communications Manager

•Selections for Audio Port Range

•How to Resolve Voice-Quality Issues