Yealink SIP-T48G Administrator's Guide

Administrator’s Guide for SIP-T2 Series/T19(P) E2/T4 Series/CP860 IP Phones
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SIP session timers T1, T2 and T4 are SIP transaction layer timers defined in RFC 3261.
These session timers are configurable on IP phones.
Timer T1
Timer T1 is an estimate of the Round Trip Time (RTT) of transactions between a SIP client
and SIP server.
Timer T2
Timer T2 represents the maximum retransmitting time of any SIP request message. The
re-transmitting and doubling 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-transmitting interval in sequence is: 0.5s, 1s, 2s, 4s, 4s, 4s, 4s, 4s, 4s and 4s.
Timer T4
Timer T4 represents the time the network will take to clear messages between the SIP
client and server.
Procedure
SIP session timer can be configured using the configuration files or locally.
Configuration File
<y0000000000xx>.cfg
Configure SIP session timer.
Parameters:
sip.timer_t1
sip.timer_t2
sip.timer_t4
Local
Web User Interface
Configure SIP session timer.
Navigate to:
http://<phoneIPAddress>/servlet
?p=settings-sip&q=load

Yealink SIP-T48G Specifications

General

Expansion module support	Yes
Handset type	Wired handset
Product type	IP Phone
Product color	Black
Volume control	-
Display diagonal	7 \
Display resolution	800 x 480 pixels
Lines quantity	- lines
Phonebook capacity	1000 entries
Number of VoIP accounts	6
AC adapter input voltage	100 - 240 V
Number of handles included	1 pc(s)

Weight and Dimensions

Width	266 mm
Height	185 mm