Yealink SIP-T31G Administrator's Guide

General Features
501
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
Web UI
Settings > SIP > SIP Session Timer T1 (0.5~10s)
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
Web UI
Settings > SIP > SIP Session Timer T2 (2~40s)
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
Web UI
Settings > SIP > SIP Session Timer T4 (2.5~60s)
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
Via: SIP/2.0/UDP 10.10.20.32:5060;branch=z9hG4bK2104991394
From: "10111" <sip:10111@10.2.1.48:5060 > ;tag=2170397024
To: <sip:1058@10.2.1.48:5060 > ;tag=200382096
Call-ID: 4_1556494084@10.10.20.32
CSeq: 2 UPDATE
Contact: <sip:10111@10.10.20.32:5060 >
Max-Forwards: 70
User-Agent: Yealink SIP-T46G 28.82.0.20
Session-Expires: 90;refresher=uac

Yealink SIP-T31G Specifications

General

Mounting kit	Yes
Number of handles included	1 pc(s)
Display diagonal	2.3 \
Display resolution	132 x 64 pixels
Operating temperature (T-T)	-10 - 50 °C
Operating relative humidity (H-H)	10 - 95 %
Voice codecs	G.722, G.729, AGC, G.729A, AJB, PLC, G.711Mu, VAD, G.711a, G.723.1, G.726, iLBC, CNG, OPUS
AC adapter input voltage	100 - 240 V
AC adapter output current	0.6 A
AC adapter output voltage	5 V
Power consumption (typical)	3 W
Lines quantity	2 lines
Phonebook capacity	1000 entries
Number of VoIP accounts	2
Sustainability certificates	RoHS, REACH
Networking standards	IEEE 802.3af, IEEE 802.1p, IEEE 802.1Q, IEEE 802.1x
Ethernet LAN data rates	10, 100, 1000 Mbit/s
Ethernet LAN interface type	Gigabit Ethernet
Mounting	Desk/Wall
Handset type	Wired handset
Product type	IP Phone
Product color	Gray
Harmonized System (HS) code	85171800

Weight and Dimensions

Depth	189 mm
Width	188 mm
Height	162 mm
Package depth	210 mm
Package width	213 mm
Package height	103 mm