Table of Contents

Product Overview
Key Features and Benefits
Specifications
Ordering Information

Cisco Voice Network Switching System

Product Overview

Cisco Voice Network Switching (VNS) system hardware and software works in conjunction with Cisco IGX 8400 series wide-area switches to provide switched virtual circuits for voice and data transmission over a Cisco wide-area ATM or Frame Relay network. Customers with tandem PBX networks realize substantial savings on facility costs, simplify network topology, and improve bandwidth efficiency with a VNS/IGX backbone. In addition, the VNS system architecture is designed to provide scalability for small to very large IGX networks.

Key Features and Benefits

• Simplifies management of existing PBX network

• Allows fill integration of voice and data across the network

• Significantly reduces operational costs

• Leverages the IGX switch`s powerful voice technologies

When a VNS system is configured with an IGX switch in a Cisco WAN Network, private branch exchanges (PBXs) using QSIG, Digital Private Network Signaling System (DPNSS), 4ESS, or Q931A (Japanese ISDN), signaling protocols can establish voice or data calls on demand, just as if they are dialing a public switched telephone network. The supported signaling protocols are all variations of the Integrated Services Digital Network (ISDN) signaling protocol. The VNS system also switches calls from PBXs using Channel Associated Signaling (T1-CAS) when used in conjunction with the IGX Universal Voice Module (UVM-C) In addition, BreakIn/BreakOut functionality to DSSI Euro ISDN public networks is also supported.

The VNS dynamically handles tandem switching and routing functions and allows the network to assume many of the tandem PBX functions of a transit PBX. This reduces the number of T1/E1 trunks and interface cards required to interconnect PBXs and enables existing tandem PBXs to be eliminated or redeployed. In some configurations, voice switching can reduce facilities costs by up to 50 percent compared to traditional PBX/TDM networks.

By consolidating traffic over fewer physical interfaces through the use of VAD, ADPCM, and CELP, the VNS/IGX network, reduces bandwidth consumption, improves voice quality, and allows the WAN network`s standard voice service features to be applied to switched voice circuits from a variety of PBXs. Cisco VAD and compression services increase network bandwidth by providing a voice compression ratio of up to 10:1.

The VNS system has a semi-distributed architecture and is typically connected to one IGX node with network connections from a number of other IGX nodes. Additional VNS systems can be added to the network, based on geographic, quantitative, or network load requirements. The VNS system can support signaling for up to 30 PBXs and can handle peak call loads of up to 40,000 calls per hour per VNS system.

Semi-distributed systems have several advantages over imbedded systems. Enhancements and improvements to the signaling protocol code and development and deployment of new features can be done quickly with no impact to the network. Only a few network elements are affected during an upgrade with a semi-distributed system, compared to every node processor affected during an upgrade with an imbedded system.

The signaling plane for call setup is handled by the VNS system, separate from the voice/data switching plane handled by the IGX switch. Each network element is optimized for specific tasks and does not place a burden on another unit`s processor. For example, the collection of billing information and statistics is a function of the VNS system`s processor, and the IGX processor`s function is connection management. The combined VNS/IGX system provides a robust, efficient, and powerful voice-switched network.

Specifications

The VNS system hardware is fully redundant, consisting of two identical units that are configured to perform as a redundant pair. Multiple levels of additional redundancy are built into the architecture, providing a fully fault-tolerant high-availability system. The carrier-class reliability of the IGX system also provides resiliency for the network.

For software specification information, access Cisco Connection Online at http://www.cisco.com.

Ordering Information

Posted: Wed Sep 27 05:15:38 PDT 2000
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