37-2
Catalyst 3750 SwitchSoftware Configuration Guide
OL-8550-09
Chapter37 Configuring TelePresence E911 IP Phone Support
Configuring TelePresence E911 IP Phone Support
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.
Figure37-2 Phone-Switch-Codec Connection
Configuring TelePresence E911 IP Phone Support
Configuration Guidelines, page37-2
Enabling TelePresence E911 IP Phone Support, page37-3
Example, page 37-3
Configuration Guidelines
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.
1Switch 3CDP-enabled IP phone
2Cisco TelePresence System with a codec
IP
1
2
3
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