Usage notes
Purpose
Network protocol
When security is
implemented, Cisco Unified
IP Phones use the TLS
protocol when securely
registering with Cisco Unified
Communications Manager.
For more information, see the
Cisco Unified
Communications Manager
Security Guide
.
TLS is a standard protocol for securing and
authenticating communications.
Transport Layer Security
(TLS)
TFTP requires a TFTP server
in your network, which can
be automatically identified
from the DHCP server. If you
want a phone to use a TFTP
server other than the one
specified by the DHCP
server, you must manually
assign the IP address of the
TFTP server by using the
Network Setup menu on the
phone.
For more information, see the
Cisco TFTP chapter in the
Cisco Unified
Communications Manager
System Guide
.
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.
Trivial File Transfer
Protocol (TFTP)
Cisco Unified IP Phones
transmit and receive RTP
streams, which utilize UDP.
UDP is a connectionless messaging protocol for
delivery of data packets.
User Datagram Protocol
(UDP)
VLAN Interaction
The Cisco Unified IP Phone 8941 and 8945 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 indicate a need to isolate the VLAN voice traffic from the VLAN data traffic.
Cisco Unified IP Phone 8941 and 8945 Administration Guide for Cisco Unified Communications Manager 10.0
(SCCP and SIP)
14
VLAN Interaction