User manual

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Linksys IP Phone Administrator Guide
Firmware Version 5.1
Chapter 1 Introducing Linksys IP Phones
Linksys IP Phone Features
SPA901 Features
The SPA901 provides the following features that are not needed with the Linksys IP phones that provide
an LCD display:
Built-in Interactive Voice Response (IVR) system to check status and change configuration
Ringer and Handset Volume Controls
Handset Input Gain Adjustment
SPA92x, SPA94x, SPA962
The SPA921, SPA922, SPA941, SPA942, and SPA962 provide an LCD display and additional features
that are not provided with the SPA901, including the following:
Line Status Indicators: Active Line, Name, and Number
Menu-Driven User Interface
Digits Dialed with Number Auto-Completion
Caller ID Name and Number and Outbound Caller ID Blocking
On-Hook Dialing
Redial from Call Logs
Personal Directory with Auto-dial (100 entries)
On Hook Default Audio Configuration (Speakerphone and Headset)
Called Number with Directory Name Matching
Call Number using Name - Directory Matching or via Caller ID
Subsequent Incoming Calls with Calling Name and Number
Name and Identity (Text) Displayed at Start Up
Distinctive Ringing Based on Calling and Called Number
Ensuring Voice Quality
Voice quality perceived by the subscribers of the IP Telephony service should be indistinguishable from
that of the PSTN. Voice quality can be measured with such methods as Perceptual Speech Quality
Measurement (PSQM), with a scale of 1–5, in which lower is better; and Mean Opinion Score (MOS),
with a scale of 1–5, in which higher is better.
Table 1-2 displays speech quality metrics associated with various audio compression algorithms. For
information about bandwidth requirements for each supported codec, refer to Table 2-1 on page 2-10.
Table 1-2 Speech Quality Metrics
Algorithm Complexity MOS Score
G.711 Very low
4.5
G.726 Low 4.1 (32 kbps)
G.729a Low–medium 4