Linksys BUSINESS SPA932 User Manual

Linksys SPA9x2 Phone Administration Guide

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The phone can be configured for secure provisioning using the factory-installed security 
certificate. To determine if the Client Certificate is installed on the phone, press 6 from the 
Product Info menu, or scroll down to the highlight Client Cert, and press the select soft button. 

This tone is played when a call has been successfully switched to secure mode. It should be 
played only for a short while (less than 30 seconds) and at a reduced level (less than -19 dBm), 
so it does not interfere with the conversation. You can configure it on the Regional web page 
under Call Progress Tones.

Defaults to 397@-19,507@-19;15(0/2/0,.2/.1/1,.1/2.1/2)

Voice quality perceived by the subscribers of the IP Telephony service should be 
indistinguishable from that of the PSTN. Linksys SPA9x2 phones support several codecs. See:

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Negotiation of the optimal voice codec sometimes depends on the ability of SPA9x2 phone to 
“match” a codec name with the far-end device/gateway codec name. SPA9x2 phones allow the 
network administrator to individually name the various codecs that are supported such that 
the correct codec successfully negotiates with the far-end equipment.

Note that SPA9x2 phones support voice codec priority. You can select up to three preferred 
codecs.

The administrator can select the low-bit-rate codec used for each line. G.711a and G.711u are 
always enabled. The following table shows the codecs supported by SPA9x2 phones. The third 
column shows the voice quality Mean Opinion Score (MOS), with a scale of 1–5, in which higher 
is better. 

Codec (Voice 
Compression 
Algorithm)

 Complexity and Description

 MOS Score

G.711 (A-law 
and u-law)

Very low complexity. Supports uncompressed 64 kbps digitized 
voice transmission 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.

4.5

Highest voice 
quality