Yealink W80, Руководство администратора

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General Features
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Timer T2 represents the maximum retransmitting time of any SIP request message. The re-transmitting and doub-
ling of T1 will continue until the retransmitting time reaches the T2 value.
Example :
The user registers a SIP account for the IP phone and then set the value of Timer T1, Timer T2 respectively (Timer
T1: 0.5, Timer T2: 4). The SIP registration request message will be re-transmitted between the IP phone and SIP
server. The re-transmitting and doubling of Timer T1 (0.5) will continue until the retransmitting time reaches the
Timer T2 (4). The total registration request retry time will be less than 64 times of T1 (64 * 0.5 = 32). The re-trans-
mitting interval in sequence is 0.5s, 1s, 2s, 4s, 4s, 4s, 4s, 4s, 4s and 4s.
Timer T4
Timer T4 represents that the network will take to clear messages between the SIP client and server.
Topic
SIP Session Timer Configuration
SIP Session Timer Configuration
The following table lists the parameters you can use to configure the SIP session timer.
Parameter sip.timer_t1 <y0000000000xx>.cfg
Description It configures the SIP session timer T1 (in seconds).
Permitted
Values
Float from 0.5 to 10
Default
0.5
Parameter
sip.timer_t2 <y0000000000xx>.cfg
Description
It configures the SIP session timer T2 (in seconds).
Permitted
Values
Float from 2 to 40
Default 4
Parameter sip.timer_t4 <y0000000000xx>.cfg
Description It configures the SIP session timer T4 (in seconds).
Permitted
Values
Float from 2.5 to 60
Default
5
Session Timer
Session timer allows a periodic refresh of SIP sessions through an UPDATE request, to determine whether a SIP
session is still active. Session timer is specified in
RFC 4028 . The phones support two refresher modes: UAC and
UAS. Whether the endpoint functions as a UAC or a UAS depends on the UA that initiates the SIP request. If the ini-
tiator is configured as UAC, the other client or the SIP server will function as a UAS. If the initiator is configured as
UAS, the other client or the SIP server will function as a UAC. The session expiration is negotiated via the Session-
Expires header in the INVITE message. The negotiated refresher is always the UAC and it will send an UPDATE
request at the negotiated session expiration. The value “refresher=uac” included in the UPDATE message means
that the UAC performs the refresh.
Example of UPDATE message (UAC mode):
UPDATE sip:1058@10.10.20.34:5060 SIP/2.0