Yealink SIP-T27G Administrator's Guide

Account Settings
306
ing the normal use of the features associated with a subscription (for example, BLF, SCA).
Default -1, the phone will invoke “account.X.sip_server.Y.failback_subscribe.enable” to take effect.
Parameter
account.X.sip_server.Y.outbound_proxy_enable
[1][2]
<MAC>.cfg
Description
It enables or disables the phone to use outbound proxy server address configured by “accoun-
t.X.outbound_proxy.Y.address”.
Note: It works only if “account.X.outbound_proxy_enable” is set to 1 (Enabled).
Permitted
Values
0-Disabled
1-Enabled
Default
1
[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.
[2]
Y is the server ID. Y=1-2.
SIP Server Name Resolution
If a domain name is configured for a server, the IP address(es) associated with that domain name will be resolved
through DNS as specified by RFC 3263. The DNS query involves NAPTR, SRV and A queries, which allows the IP
phone to adapt to various deployment environments. The IP phone performs NAPTR query for the NAPTR pointer
and transport protocol (UDP, TCP, and TLS), the SRV query on the record returned from the NAPTR for the target
domain name and the port number, and the A query for the IP addresses.
If an explicit port (except 0) is specified, A query will be performed only. If a server port is set to 0 and the transport
type is set to DNS NAPTR, NAPTR and SRV queries will be tried before falling to A query. If no port is found through
the DNS query, 5060 will be used.
Topic
SIP Server Name Resolution Configuration
SIP Server Name Resolution Configuration
The following table lists the parameters you can use to configure the SIP server name resolution.
Parameter
account.X.sip_server.Y.transport_type
[1][2]
<MAC>.cfg
Description
It configures the type of transport protocol.
Permitted
Values
0-UDP
1-TCP
2-TLS
3-DNS NAPTR, if no server port is given, the device performs the DNS NAPTR and SRV queries for
the service type and port.
Default
0
Web UI
Account > Register > SIP Server Y > Transport
Parameter
account.X.naptr_build
[1]
<MAC>.cfg
Description
It configures the way of SRV query for the phone to be performed when no result is returned from the
NAPTR query.
Permitted
0-SRV query using UDP only

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