|
|
The Cisco IP Phone 7960 enables you to communicate using voice over a data network. To do this, the Cisco IP Phone 7960 depends upon and interacts with several other key IP telephony components, including Cisco CallManager.
These sections provide you with an overview of the Cisco IP Phone 7960 and its interactions with other key components of the voice over IP (VoIP) network:
The Cisco IP Phone 7960 provides functionality similar to that of a traditional analog phone. However, IP phones also allow you to configure and manage them like other network devices.
Related Topics
The Cisco IP Phone 7960 is a full-feature telephone that provides voice communication over an IP network. The Cisco IP Phone 7960 functions as an office telephone, replacing a traditional analog telephone in an IP telephony network.
The Cisco IP Phone 7960 supports G.711 and G.729a audio compression, and includes these features (see Figure 1-1):
The Cisco IP Phone 7960 supports several industry-standard and Cisco networking protocols required for voice communication. See Table 1-1 for an overview of the supported networking protocols.
| Networking Protocol | Purpose | Usage Notes |
|---|---|---|
IP is a messaging protocol that addresses and sends packets across the network. | To communicate using IP, network devices must have an IP address, subnet, and gateway assigned to them. An IP address, subnet, and gateway are automatically assigned if you are using the Cisco IP Phone 7960 with DHCP. If you are not using DHCP, you must manually assign these to each phone locally. | |
VoIP enables you to transfer voice communications over a data network using the Internet Protocol. |
| |
BOOTP enables a network device, such as the Cisco IP Phone 7960 to discover certain startup information, such as its IP address. | If you are using BOOTP to assign IP addresses to the Cisco IP Phone 7960, this is displayed in the network configuration settings on the phone. | |
TFTP allows you to transfer files over the network. On the Cisco IP Phone 7960, TFTP enables you to obtain 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 more than one TFTP server is running in your network, you must manually assign a TFTP server to each phone locally. | |
DHCP dynamically allocates and assigns an IP address to network devices. DHCP enables you to connect the IP phone into the network and become operational without manually assigning an IP address and configuring additional required network parameters. | DHCP is enabled by default. If disabled, you must manually configure the IP address, subnet mask, gateway, an TFTP server on each phone locally. | |
CDP is a device-discovery protocol that runs on all Cisco-manufactured equipment. Using CDP, a device can advertise its existence to other devices and receive information about other devices in the network. The Cisco IP Phone 7960 uses CDP to communicate information such as auxiliary VLAN ID, per port power management details, and quality of service (QoS) configuration information with the Cisco Catalyst switch. |
| |
RTP is a standard for transporting real-time data, such as interactive voice and video over data networks. |
| |
UDP is a connectionless messaging protocol for delivery of data packets. |
|
The Cisco IP Phone 7960 functions much like a traditional analog phone allowing you to place and receive telephone calls. The phone also supports features such as call forwarding, redialing, speed dialing, transferring calls, placing conference calls, and accessing voice mail. The Cisco IP Phone 7960 Getting Started guide provides information about how to use each of these telephony features. Each phone ships with this guide, and you should provide all users with the copy included with their phone.
In addition to these traditional telephony features, the Cisco IP Phone 7960 also includes features enabling you to administer and monitor it as an IP networking device. On the phone, you can locally configure features such as DHCP, TFTP, and IP settings. You can also obtain statistics about a current call or firmware versions on the phone. From Cisco CallManager, you can modify additional settings, which are viewable from the phone's network configuration settings. Use this guide, Cisco IP Phone 7900 Family Administration Guide, for information about configuring these settings.
The Cisco IP Phone 7960 includes connections for connecting to the data network, for providing power to the phone, and for connecting a headset to the phone.
The Cisco IP Phone 7960 has two RJ-45 ports that each support 10/100 Mbps half- or full-duplex connections to external devices--network port and access port. You can use either Category 3 or 5 cabling for 10 Mpbs connections, but use Category 5 for 100 Mbps connections. On both the network port and access port, use full-duplex mode to avoid collisions.
Network port
Use the network port to connect the phone to the network. You must use a straight-through cable on this port. The phone can also obtain inline power from the Cisco Catalyst switch over this connection. See the "Providing Power to the IP Phone" section for details.
Access port
Use the access port to connect a network device, such as a computer, to the phone. You must use a straight-through cable on this port.
The Cisco IP Phone 7960 can be powered by the following sources:
 |
Note Only the network port supports inline power from the Cisco Catalyst switches. |
For redundancy, you can use the Cisco AC adapter even if you are using inline power from the Cisco Catalyst switches. The IP phone can share the power load being used from the inline power and external power source. If either the inline power or the external power goes down, the phone can switch entirely to the other power source.
To use this redundancy feature you must set the inline power mode to auto on the Cisco Catalyst switch. Next, connect the un-powered Cisco IP Phone 7960 to the network. After the phone powers up, connect the external power supply to the phone.
The Cisco IP Phone 7960 supports a four or six-wire headset jack (Plantronic's compatible is required) for the Cisco IP Phone 7960. The Volume and Mute controls will also adjust volume to the earpiece and mute the speech path of the headset. The headset activation key is located on the front of the Cisco IP Phone.
To function in the IP telephony network, the Cisco IP Phone 7960 must be connected to a networking device, such as a Cisco Catalyst switch, to obtain network connectivity. The phone also must be registered with a Cisco CallManager system in order to send and receive calls.
Cisco CallManager is an open and industry-standard call processing system. Cisco CallManager software runs on a Windows NT server and sets up and tears down calls between phones, integrating traditional PBX functionality with the corporate IP network. Cisco CallManager manages the components of the IP telephony system, the phones, access gateways, and the resources necessary for such features as call conferencing and route planning.
For information about configuring Cisco CallManager to work with the IP devices described in this chapter, refer to the Cisco CallManager Administration Guide, Release 3.0 and the Configuration Notes for Cisco CallManager Release 3.0 publications.
The Cisco IP Phone 7960 has an internal Ethernet switch, which enables it to switch traffic coming from phone, access port and the network port.
If a computer is connected to the access port, packets traveling to and from the computer and to and from the phone share the same physical link to the switch and the same port on the switch.
This configuration has these implications for the VLAN configuration on the network:
You can resolve these issues by isolating the voice traffic onto a separate VLAN on each of the ports connected to a phone. The switch port configured for connecting a phone would have separate VLANs configured for carrying:
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 more information, refer to the documentation included with the Cisco Catalyst switch.
To connect to the VoIP network, the Cisco IP Phone 7960 goes through a standard startup process. Some of these steps are optional, depending on the specific network configuration.
Obtaining Power from the Switch
You connect the Cisco IP Phone 7960 to a Cisco Catalyst switch with one of the modules that can provide power to the phone (WS-X6348-RJ45V 10/100 or WS-PWR-PANEL).
If you use this optional configuration, when you connect the Cisco IP Phone 7960 to the switch, the phone receives phantom power and powers up. The phone then sends CDP notifications to the switch indicating it is ready to receive CDP packets and indicating the power requirement. The switch allocates power and sends it over the network cable.
Loading the Stored Phone Image
The Cisco IP Phone 7960 has non-volatile Flash memory in which it stores firmware images and user-defined preferences. At startup, the phone runs a boostrap loader that loads a phone image stored in Flash memory. Using this image, the phone initializes its software and hardware.
Configuring VLAN
If the Cisco IP Phone 7960 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 DHCP request for an IP address.
Obtaining an IP Address
If the Cisco IP Phone 7960 is using DHCP to obtain an IP address, the phone queries the DHCP server to obtain one.
Accessing TFTP Server
In addition to assigning an IP address, the DHCP server also directs the Cisco IP Phone 7960 to a TFTP Server. If the phone has a statically defined IP address, you must configure the TFTP server locally on the phone and the phone goes to the TFTP server directly.
Requesting the Configuration File
The TFTP server has configuration files (.cnf file format) for telephony devices, which define parameters for connecting to Cisco CallManager.
If you have enabled auto-registration in Cisco CallManager, the phones access a default configuration file (sepdefault.cnf) from the TFTP server. If you have manually entered the phones into the Cisco CallManager database, the phone accesses a .cnf file corresponding to its device name.
Contacting Cisco CallManager
The configuration file defines how the Cisco IP Phone 7960 communicates with Cisco CallManager. After obtaining the file from the TFTP server, the phone next attempts to make a TCP connection to the highest priority Cisco CallManager on the list.
If the phone was manually added to the database, Cisco CallManager identifies the phone. If the phone was not manually added to the database and auto-registration is enabled in Cisco CallManager, the phone attempts to auto-register itself in the Cisco CallManager database.
After the phone contacts the Cisco CallManager system, Cisco CallManager instructs the phone which image load to run. If this image load differs from the one currently loaded on the phone, the phone contacts the TFTP server to request the new image file, which is stored as a .bin file.
To install and configure the Cisco IP Phone 7960, you must configure some network settings, set up Cisco CallManager, and make changes locally on the phone.
Refer to Table 1-2 for an overview of these required procedures. For detailed information about these steps, refer to the referenced sources.
| Task | Purpose | For More Information |
|---|---|---|
Configure routers, gateways, and switches to handle voice communication | Sets up the IP telephony network. | See documentation included with these devices. |
Configure Cisco CallManager | Supports call processing and handling in the network. | See Cisco CallManager Administration Guide or online help in the Cisco CallManager application. |
Add users to Cisco CallManager | Associates user with specific phone so users can access web pages to configure call forwarding, voice mail, and speed dialing. | See Cisco CallManager Administration Guide or online help in the Cisco CallManager application. |
Decide whether to auto-register phones or add to Cisco CallManager database manually | Determines how phone is added to the Cisco CallManager database and how directory number is assigned. |
|
Decide whether to use Cisco AC adapter for power or to obtain power from Cisco Catalyst switch | Determines whether the phone receives power from external power source over a power cord or from the in-line power source over the Ethernet cable. |
|
Connect phone to the network | Adds the phone to the network. | |
Configure locally-defined network settings on the Cisco IP Phone 7960 | Sets IP settings and TFTP server if not using DHCP in the network. | See the "Configuring IP Settings" section and the "Configuring TFTP Options" section. |
Posted: Thu Aug 3 09:36:08 PDT 2000
Copyright 1989-2000©Cisco Systems Inc.