Yealink SIP-T27G Administrator's Guide

Network Configurations
57
Parameter
account.X.nat.udp_update_enable
[1]
<MAC>.cfg
Description
It sets the type of keep-alive packets sent by phone.
Permitted
Values
0-Disabled
1-Default (the phone sends the corresponding packets according to the transport protocol)
2-Options (the phone sends SIP OPTIONS packets to the server)
3-Notify (the phone sends SIP NOTIFY packets to the server)
Default
1
Web UI
Account > Advanced > Keep Alive Type
Parameter
account.X.nat.udp_update_time
[1]
<MAC>.cfg
Description
It configures the interval (in seconds) at which the phone sends a keep-alive package.
Note: It works only if “account.X.nat.udp_update_enable” is set to 1, 2 or 3.
Permitted
Values
Integer from 0 to 3600
Default
30
Web UI
Account > Advanced > Keep Alive Interval(Seconds)
[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.
Rport Configuration
Rport allows a client to request that the server sends the response back to the source IP address and port from
which the request originated. It helps the phone traverse symmetric NATs.
Rport feature depends on support from a SIP server. For more information, refer to RFC 3581.
The following table lists the parameter you can use to configure rport.
Parameter
account.X.nat.rport
[1]
<MAC>.cfg
Description
It enables or disables the phone to add the "rport" parameter in the Via header.
Permitted
Values
0-Disabled
1-Enabled, the INVITE Contact header uses the port in the "rport" parameter but does not use the
source IP address in the "received" parameter in the Via header of server's response.
2-Enable Direct Process, the INVITE Contact header uses the port in the "rport" parameter and uses
the source IP address in the "received" parameter in the Via header of server's response.
Default
0
Web UI
Account > Advanced > RPort
[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 Port and TLS Port Configuration
You can configure the SIP and TLS source ports on the phone. Otherwise, the phone uses default values (5060 for
UDP/TCP and 5061 for TLS).

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