Yealink SIP-T54S Administrator's Manual page 14

Administrator's Guide for SIP-T2 Series/T19(P) E2/T4 Series/T5 Series/CP860/CP920 IP Phones
to use content types of other applications other than the one you are trying to let through what
has been denied.
User Agent Server (UAS)
UAS is a server that hosts the application responsible for receiving the SIP requests from a UAC,
and on reception it returns a response to the request back to the UAC. The UAS may issue
multiple responses to the UAC, not necessarily a single response. Communication between UAC
and UAS is client/server and peer-to–peer.
Typically, a SIP endpoint is capable of functioning as both a UAC and a UAS, but it functions
only as one or the other per transaction. Whether the endpoint functions as a UAC or a UAS
depends on the UA that initiates the request.
Summary of Changes
This section describes the changes to this guide for each release and guide version.
Changes for Release 81, Guide Version 81.91
Documentations of the newly released CP920 IP phones have been added.
The following section is new for this version:
Touch Tone

Off Hook Contact Dialing

Noise Suppression

Smart Noise Block

Major updates have occurred to the following sections:
Softkey Layout

Bluetooth

Local Conference

Changes for Release 81, Guide Version 81.90
The following section is new for this version:
Ringer Volume

Major updates have occurred to the following sections:
Physical Features of IP Phones

Key Features of IP Phones

Connecting the Optional USB Flash Drive (Only Applicable to SIP-

T54S/T52S/T48G/T48S/T46G/T46S/T42S/T41S/T29G/T27G/CP860/CP920 IP
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