C H A P T E R
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Overview of Cisco VG450 Voice Gateway
Cisco High-Density Analog Voice Gateway provide enterprises, managed services providers, and service
providers the ability to directly connect public-switched telephone networks (PSTNs) and existing telephony
equipment to Cisco 4000 Series Integrated Services Routers. These fixed-port (FXS and FXO) modules
provide Dual-Tone Multifrequency (DTMF) detection, voice compression and decompression, call progress
tone generation, Voice Activity Detection (VAD), echo cancellation, and adaptive jitter buffering. Cisco
VG450 Voice Gateway is a high-density analog voice gateway. It is an intermediate path that enables TDM
to IP transition.
The Cisco VG450 Voice Gateway supports the following interfaces:
• Gigabit Ethernet (GE)
• USB
• Network Interface Module (NIM)
• Single-Wide Service Module (SWSM) interface
• Double-Wide Service Module (DWSM) interface
This chapter contains the following sections:
•
Features and Benefits of Cisco VG450 Voice Gateway, on page 1
•
Slot, Bay, and Ports, on page 4
•
Cisco VG450 Voice Gateway Chassis, on page 6
•
Technical and Compliance Specifications, on page 6
•
Platform and Software Requirements, on page 8
Features and Benefits of Cisco VG450 Voice Gateway
Cisco VG450 Voice Gateway provides VoIP connectivity to analog devices, such as analog desk phones,
analog conference room phones, fax machines and modems. Cisco 450 Voice Gateway provides several
improvements from the previous high-density analog and digital extension modules (EVMs), in the following
ways:
•
On-board Digital Signal Processor (DSP)—
The FXO and FXS service modules contain an onboard
DSP and don’t require the router to have a dedicated packet voice DSP module (PVDM) on the
motherboard. The DSP on the voice module is necessary for the voice features. It also provides for echo
cancellation of up to 128-ms echo-tail length for demanding network conditions.
•
Support for Online Insertion and Removal (OIR)—
The FXS and FXO service modules support Online
Insertion and Removal (OIR), reducing the downtime required for new or replacement modules. The
Cisco 450 Voice Gateway Hardware Installation Guide
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