Cisco 7912G - Manual (Page 34)

Chapter 1 An Overview of the Cisco Unified IP Phone
What Networking Protocols Are Used?
1-6
Cisco Unified IP Phone Administration Guide for Cisco Unified CallManager 5.0 (SIP), Cisco Unified IP Phones
OL-8131-01
Internet Protocol (IP) IP is a messaging protocol that
addresses and sends packets across
the network. To communicate using IP, network
devices must have an assigned IP
address, subnet, and gateway.
IP addresses, subnets, and gateways
identifications are automatically
assigned if you are using the
Cisco Unified IP Phone with
Dynamic Host Configuration
Protocol (DHCP). If you are not
using DHCP, you must manually
assign these properties to each phone
locally.
Real-Time Transport
(RTP) RTP is a standard for transporting
real-time data, such as interactive
voice and video, over data networks. Cisco Unified IP Phones use the RTP
protocol to send and receive
real-time voice traffic from other
phones and gateways.
Session Description
Protocol (SDP) SDP is the portion of the SIP that
determines which parameters are
available during a connection
between two endpoints. Conferences
are established 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 the Cisco Unified
CallManager or the Media Gateway
in operation. Some SIP endpoints
may allow these parameters to be
configured on the endpoint itself.
Transmission Control
Protocol (TCP) TCP is a a connection-oriented
transport protocol. Cisco Unified IP Phones use TCP to
connect to
Cisco Unified CallManager.
Trivial File Transfer
Protocol (TFTP) TFTP allows you to transfer files
over the network.
On the Cisco Unified IP Phone,
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
more than one TFTP server is
running in your network, you must
manually assign a TFTP server to
each phone locally.
Table 1-1 Supported Networking Protocols on the Cisco Unified IP Phone (continued)
Networking Protocol Purpose Usage Notes