IP Multicast Solution Architecture

Cisco IOS Multicast for Hoot & Holler Networks


Data Sheet

Cisco IOS Multicast for
Hoot & Holler Networks

Hoot & Holler is a specialized, private telephony system that facilitates communications in industries that depend upon very rapid dissemination of information. Traditionally, Hoot & Holler has been used as a means to provide a one-to-many or many-to-many conferencing service for voice communications.

While popular in the publishing, transportation, power plant, and manufacturing industries, Hoot & Holler networks are most commonly deployed in the financial brokerage industry for market updates and trading. Hoot & Holler networks are typically spread over four to eight sites, although financial networks may have hundreds of sites interconnected.

A typical brokerage firm has several Hoot & Holler networks to service its many markets, such as equity, retail, and bonds. These networks are used either once a day for the "Morning Report" or throughout the day for brokers to "shout" orders onto busy trading floors. In the past, brokerage houses relied upon point-to-point telco circuits and customized Hoot & Holler bridging and mixing functionality to provide an "always-on" multi-user audio conference network without requiring users to dial in. While the network is always active, it is not always in use.

Cisco Systems offers Cisco Hoot & Holler network solutions based upon its proven Cisco IOS® Multicast and Cisco IOS Voice-over-IP technologies. The Cisco IP-based Hoot network only uses bandwidth when it is in use; when it is not, the same bandwidth can be used to carry other traffic. The IP backbone interoperates with existing Hoot & Holler end-station equipment, such as microphones, turrets, Hoot phones, or squawk boxes, as well as bridges and mixers, for a seamless transition. Brokerage houses can adapt this solution to eliminate costly private telco circuits and reap significant operational cost savings—up to millions of dollars per year—for a rapid return on investment.

Technology Summary

Cisco Hoot & Holler networks rely upon a variety of Cisco IOS software features, including Voice over IP, audio compression, and routing update protocol (RTP) header compression. The Hoot & Holler solution is unique in its additional need to replicate a single voice signal for simultaneous arrival at multiple end stations. This replication is achieved using Cisco IOS Multicast technologies.

Multicast comprises a single content stream across switched networks, which is replicated at branch points closest to viewers for minimal resource consumption. This uses bandwidth much more efficiently, reaching more users at a lower cost per user.

The primary Cisco IOS Multicast technology required for Cisco Hoot & Holler networking is Protocol Independent Multicast version 2 (PIMv2). PIM provides intradomain multicast forwarding for all underlying unicast routing protocols. PIM distribution trees are dynamic; that is, the network can respond to accommodate senders and receivers joining and departing the network in real-time. PIM is independent of any underlying unicast protocol such as Open Shortest Path First Protocol (OSPF) or Border Gateway Protocol (BGP), and supports explicit join (sparse mode), flood-and-prune (dense mode), or hybrid sparse-dense modes. For Hoot & Holler, Cisco PIMv2 multicast technology should run in sparse mode. Sparse mode (RFC 2362) relies upon an explicit joining method before attempting to send multicast data to receivers of a multicast group (Figure 1).

Figure 1   PIMv2 Sparse Mode


Brokerage houses and other Hoot & Holler network customers can reap significant performance and cost benefits from shifting its underlying network from telco circuits to the Cisco Hoot & Holler solution with Cisco IOS Multicast:

  • Cost savings—through elimination of costly private telco circuits and bandwidth conservation
  • Scalability—adding more end stations does not require additional circuits; because Cisco IOS Multicast replication vastly simplifies expansion, making it easier and faster to deploy than circuit-based solutions
  • Interoperability—standards-based software interoperates with the data network and existing Hoot & Holler end station equipment, bridges, and mixers via analog bridges

Platform Support

Cisco IOS Multicast for Hoot & Holler is initially supported on the Cisco 2600 and 3600 multiservice platforms.

For More Information

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