System information

Getting Started
Feature Overview
Cisco SPA232D Administration Guide 8
1
Understanding Voice Service Operations
The ATA allows calls to be made by using SIP-based Voice-over-IP (VoIP) services
and traditional telephone Public Switched Telephone Network (PSTN) services.
Calls can be placed and received by using an analog phone or fax machine and
Cisco SPA302D handsets.
The ATA maintains the state of each call and makes the proper reaction to user
input events (such as on/off hook or hook flash). Because the ATA uses the Session
Initiation Protocol (SIP), it is compatible with most Internet Telephony Service
Provider (ITSP) offerings.
ATA Voic e Features
The ATA can be custom provisioned within a wide range of configuration
parameters. The following sections describe the factors that contribute to voice
quality:
• Supported Codecs
• SIP Proxy Redundancy
• Other ATA Voice Features
Services
Ready
Platform
Telephone/fax
Ethernet
V
V
V
Phone
V
V
PSTN
Internet
Service Provider
VoIP Infrastructure
SIP proxy
IP
Voice
gateway
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