Hoot and Holler
A hoot and holler network, as illustrated in Figure B-1 (also known as a junkyard circuit, squawk box
system, holler down circuit, or shout down circuit), provides always-on
multiuser conferences without requiring users to dial in to a conference bridge.
This type of network was devised more than 50 years ago when local
concentrations of small, specialized businesses needed to communicate common,
time-critical information. Junkyard operators up and down the East Coast of the
United States were among the first users of these networks. They began to
install their own telephone wires, speakers (called squawk boxes), and microphones to share information
with other locations about parts that their customers needed. These networks
functioned as crude, do-it-yourself, business-to-business intercom
systems.
Hoot and holler broadcast audio network systems have evolved
into the specialized leased-line networks of today. Financial and brokerage
firms use these networks to trade stocks and currency futures and provide
time-critical information, such as market updates and morning reports. In
addition to financial and brokerage firms, users of various forms of hoot and
holler networks include news agencies, publishers, government and municipal
emergency response agencies, weather bureaus, transportation providers, utility
operators, manufacturers, collectibles dealers, talent agencies, airlines, and
nationwide salvage yard organizations.
Hoot and holler over IP transports hoot and holler voice
traffic over traditional data networking equipment on an existing enterprise
multiservice network. Hoot and holler enables businesses to eliminate expensive,
dedicated leased lines while protecting investments in existing hoot and holler
equipment such as turrets, bridges, and four-wire telephones. In addition to
eliminating leased lines, running hoot and holler traffic over an IP network
allows businesses to utilize bandwidth more efficiently. When bandwidth is not
being used for hoot and holler traffic, it can be made available for data.
Hoot and holler requires that IP
multicast be active on the routers that support the hoot and holler circuit. The
connections are configured using special dial peers configured with session protocol multicast.