Yealink SIP-T48U 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-T48U Specifications

General

Handset type	Wired handset
Product type	IP Phone
Product color	Gray
USB 2.0 ports quantity	USB 2.0 ports have a data transmission speed of 480 Mbps, and are backwards compatible with USB 1.1 ports. You can connect all kinds of peripheral devices to them.
Expansion module support	Yes
Ethernet LAN (RJ-45) ports	2
Display diagonal	7 \
Display resolution	800 x 480 pixels
Lines quantity	- lines
Phonebook capacity	1000 entries
Number of VoIP accounts	16
Voice codecs	AGC, AJB, AMR-WB, CNG, G.711, G.722, G.723.1, G.726, G.729ab, VAD, iLBC
Security algorithms	AES, HTTPS, SRTP, TLS
Ethernet LAN data rates	10, 100, 1000 Mbit/s
Ethernet LAN interface type	Gigabit Ethernet
Front camera	-
AC adapter input voltage	100 - 240 V
Operating temperature (T-T)	0 - 40 °C
Operating relative humidity (H-H)	10 - 95 %
Keypad number of keys	29
Number of handles included	1 pc(s)
Harmonized System (HS) code	85171800

Weight and Dimensions

Width	226 mm
Height	185 mm