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Cisco IOS Release 12.1(5)T
Cisco Hoot and Holler over IP
The voice multicasting feature on Cisco 2600 and Cisco 3600 series routers uses Cisco Voice-over-IP
(VoIP) technology to create a permanently conn ected point -to -multip oint hoot and h oll er network over
an IP connection.
Four-wire E&M, E1/T1, FXO, and FXS configurations provide continuous VoIP connections across a
packet network using the connection-trunk mechanism. By using the inherent point-to-multipoint
connectivity of IP multicast (IPmc), the routers can take several inbound voice streams from the
traditional hoot devices and forward the packetized voice over the IP network to all parties within a
defined hoot and holler group.
This feature module describes the Cisco Hoot and Holler over IP feature and contains the following
sections:
•Feature Overview, page 1
•Supported Platforms, page 12
•Supported Standards, MIBs, and RFCs, page 12
•Configuration Tasks, page12
•Command Reference, page 29
•Glossary, page 31

Feature Overview

Hoot and holler networks provide "always on" multiuser conferences without requiring that users dial
into a conference. These networks came into being more than 40 years ago when local concentrations
of small specialized businesses with common, time-critical informational interests—junkyards, for
example—began to install their own phone wires, speakers (called “squawk boxes”), and microph ones
between their businesses to ask each other about parts customers needed. These networks functioned as
crude, do-it-yourself, business-to-business intercom systems.
Hoot and holler broadcast audio network systems have since evolved into the specialized leased-line
networks used by financial and brokerage firms to trade stocks and currency futures and the
accompanying time-critical information such as market updates and morning reports.
Users of various forms of hoot and holler networks now include brokerages, news agencies, publishers,
weather bureaus, transportation providers, power plant operators, manufacturers, collectibles dealers,
talent agencies, and nationwide salvage yard organizations.