Cisco SPA962-NA Administration Guide - Page 18

SPA900 Series Features • Ringer and Handset Volume Controls • Handset Input Gain Adjustment Chapter 1 Introducing Linksys 900 Series IP Phones SPA92x, SPA94x, and SPA962 Features 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. Table 1-2 Speech Quality Metrics Algorithm G.711 G.726 G.729a G.729 G.723.1 Bandwidth 64 kbps 16, 24, 32, 40 kbps 8 kbps 8 kbps 6.3, 5.3 kbps Complexity Very low Low Low-medium Medium High MOS Score 4.5 4.1 (32 kbps) 4 4 3.8 Linksys 900 Series IP Phone Administrator Guide 1-4 Document Version 3.0