C H A P T E R 41 Configuring Telepresence E911 Ip Phone Support; Configuration Guidelines - Cisco Catalyst 3750-X Software Configuration Manual

Configuring TelePresence E911 IP Phone Support
Use the TelePresence E911 IP phone support feature to ensure that the IP phone is always on and
available for emergency calls. When a CDP-enabled IP phone is connected to the codec through a switch,
you can configure the switch to forward CDP packets from the IP phone only to the codec in the Cisco
TelePresence System. The switch adds ingress-egress port pairs to the CDP forwarding table. An
ingress-egress port pair is a one-to-one mapping between an ingress switch port connected to the IP
phone and an egress switch port connected to the codec.
The IP phone and the codec communicate through the IP network. If power to the codec fails, is disrupted
or if the codec fails, the IP phone is still connected to the IP network and is available for emergency calls.
The switch forwards all CDP packets received on the ingress port to the egress port. If multiple IP phones
are connected to the codec through a single port on the switch, only one phone communicates with it
through the IP network. This phone is usually the one that sent the first CDP packet received by the
codec.
Figure 41-2
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Configuring TelePresence E911 IP Phone Support
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Configuration Guidelines

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Catalyst 3750-X and 3560-X Switch Software Configuration Guide
41-2
Phone-Switch-Codec Connection
IP
Switch
Cisco TelePresence System with a codec
Configuration Guidelines, page 41-2
Enabling TelePresence E911 IP Phone Support, page 41-3
Example, page 41-3
You must use only CDP-enabled phones with TelePresence E911 IP phone support.
You can connect the IP phone and codec in the Cisco TelePresence System through any two ports in
a switch stack.
Chapter 41 Configuring TelePresence E911 IP Phone Support
CDP-enabled IP phone
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