Yealink Yealink SIP-T46G, Руководство администратора

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Configuring Basic Features
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6. Select the desired refresher from the pull-down list of Session Refresher.
7. Click Confirm to accept the change.
Call hold provides a service of placing an active call on hold. When a call is placed on
hold, the IP phones send an INVITE request with HOLD SDP to request remote parties to
stop sending media and to inform them that they are being held. IP phones support two
call hold methods, one is RFC 3264, which sets the “a” (media attribute) in the SDP to
sendonly, recvonly or inactive (e.g., a=sendonly). The other is RFC 2543, which sets the
“c” (connection addresses for the media streams) in the SDP to zero (e.g., c=0.0.0.0).
Call hold tone allows IP phones to play a warning tone at regular intervals when there is
a call on hold. The warning tone is played through the speakerphone.
IP phones also support Music on Hold (MoH) feature. MoH is the business practice of
playing recorded music to fill the silence that would be heard by the party who has
been placed on hold. To use this feature, specify a SIP URI pointing to a MoH server
account. When a call is placed on hold, the IP phone will send an INVITE message to the
specified MoH server account according to the SIP URI. The MoH server account
automatically responds to the INVITE message and immediately plays audio from some
source located anywhere (LAN, Internet) to the held party.