Configuring Voice Services
ATA Software Features
Cisco Small Business WRP400 Administration Guide
29
3
The WRP400 maintains the state of each call it terminates and makes the proper
reaction to user input events (such as on/off hook or hook flash). The WRP400 uses
the Session Initiation Protocol (SIP) open standard, so there is little or no
involvement by a “middle-man” server or media gateway controller. SIP allows
interoperation with all ITSPs that support SIP.
ATA Software Features
The WRP400 is equipped with a full featured, fully programmable ATA that can be
custom provisioned within a wide range of configuration parameters. The
following sections describe the factors that contribute to voice quality:
•
“Supported Codecs,” on page 29
•
“SIP Proxy Redundancy,” on page 30
•
“Other ATA Software Features,” on page 31
Supported Codecs
The WRP400 supports the following codecs:
•
G.711u
(configured by default) and G.711a
G.711 (A-law and m
μ
-law) are very low complexity codecs that support
uncompressed 64 kbps digitized voice transmissions at one through ten 5 ms
voice frames per packet. This codec provides the highest voice quality and
uses the most bandwidth of any of the available codecs.
WRP400
Telephone/fax
Ethernet
Internet
Access Device
V
V
V
Phone
V
V
PSTN
Internet
Service Provider
VoIP Infrastructure
SIP proxy
IP
Voice
gateway
252075