Yealink SIP-T27G Administrator's Guide

Administrator’s Guide for SIP-T2 Series/T4 Series/T5 Series/CP920 IP Phones
495
Supported: 100rel
Allow-Events: talk,hold,conference,refer,check-sync
Content-Length: 302
Topic
100 Reliable Retransmission Configuration
100 Reliable Retransmission Configuration
The following table lists the parameter you can use to configure the 100 reliable retransmission.
Parameter
account.X.100rel_enable
[1]
<MAC>.cfg
Description
It enables or disables the 100 reliable retransmission feature.
Permitted
Values
0-Disabled
1-Enabled
Default
0
Web UI
Account > Advanced > Retransmission
[1]
X is the account ID. For T57W/T54W/T48U/T48S/T48G/T46U/T46S/T46G/T29G, X=1-16; for
T53W/T53/T43U/T42G/T42U/T42S, X=1-12; for T41P/T41S/T27G, X=1-6; for T40P/T40G/T23P/T23G, X=1-3; for T21
(P) E2, X=1-2; for T19(P) E2/CP920, X=1.
SIP Session Timer
SIP session timers T1, T2 and T4 are SIP transaction layer timers defined in RFC 3261. These session timers are
configurable on the 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 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.

Yealink SIP-T27G Specifications

General

Mounting	Desk/Wall
Handset type	Wired handset
Product type	IP Phone
Product color	Black, Gold
Wall mountable	Yes
Display diagonal	3.66 \
Display resolution	240 x 120 pixels
RJ-9 ports quantity	2
USB 2.0 ports quantity	1
Voice codecs	CNG, G.711, G.722, G.723.1, G.726, G.729, G.729ab, VAD, iLBC
Dual-Tone Multi-Frequency (DTMF) modes	SIP info
Lines quantity	8 lines
Phonebook capacity	1000 entries
Number of VoIP accounts	6
Bluetooth	-
Security algorithms	AES, MD5
Networking standards	IEEE 802.1Q, IEEE 802.1p, IEEE 802.1x, IEEE 802.3af
Ethernet LAN interface type	Gigabit Ethernet
Volume control	Digital
Operating temperature (T-T)	-10 - 50 °C
Operating relative humidity (H-H)	10 - 95 %
Cables included	LAN (RJ-45)
Number of handles included	1 pc(s)
Harmonized System (HS) code	85171800

Weight and Dimensions

Depth	210 mm
Width	265 mm
Height	170.5 mm