![](/images/new-backgrounds/1309955/30995529x1.webp)
Chapter 1 Introducing Linksys IP Phones
Linksys IP Phone Features
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
•
•Digits Dialed with Number
•Caller ID Name and Number and Outbound Caller ID Blocking
•
•Redial from Call Logs
•Personal Directory with
•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
Table
Table
Algorithm | Complexity | MOS Score |
|
|
|
G.711 | Very low | 4.5 |
G.726 | Low | 4.1 (32 kbps) |
|
|
|
G.729a | 4 | |
|
|
|
G.729 | Medium | 4 |
|
|
|
G.723.1 | High | 3.8 |
|
|
|
Note Linksys IP phones support all the above voice coding algorithms.
| Linksys IP Phone Administrator Guide |
Firmware Version 5.1 |