Yealink SIP-T48U Administrator's Guide

General Features
494
Default
0
Web UI
Features > General Information > Hide Feature Access Codes
Accept SIP Trust Server Only
Accept SIP trust server only enables the phones to only accept the SIP message from your SIP server and outbound
proxy server. It can prevent the phone from receiving the ghost calls whose phone number maybe 100, 1000 and
so on. If you enable this feature, the phone cannot accept an IP address call.
Topic
Accept SIP Trust Server Only Configuration
Accept SIP Trust Server Only Configuration
The following table lists the parameters you can use to configure accept SIP trust server only.
Parameter
sip.trust_ctrl <y0000000000xx>.cfg
Description
It enables or disables the phone to only accept the SIP message from the SIP and outbound proxy
server.
Permitted
Values
0-Disabled
1-Enabled, users cannot accept the IP call
Default
0
Web UI
Features > General Information > Accept SIP Trust Server Only
100 Reliable Retransmission
As described in RFC 3262, the 100rel tag is for the reliability of provisional responses. When presented in a Sup-
ported header, it indicates that the phone can send or receive reliable provisional responses. When presented in a
Require header in a reliable provisional response, it indicates that the response is to be sent reliably.
Example of a SIP INVITE message:
INVITE sip:1024@pbx.test.com:5060 SIP/2.0
Via: SIP/2.0/UDP 10.3.6.197:5060;branch=z9hG4bK1708689023
From: "1025" <sip:1025@pbx.test.com:5060 > ;tag=1622206783
To: <sip:1024@pbx.test.com:5060 >
Call-ID: 0_537569052@10.3.6.197
CSeq: 2 INVITE
Contact: <sip:1025@10.3.6.197:5060 >
Authorization: Digest username="1025", realm="pbx.test.com", nonce="BroadWorksXi5stub71Ts2nb05BW", uri-
i="sip:1024@pbx.test.com:5060", response="f7e9d35c55af45b3f89beae95e913171", algorithm=MD5, cnon-
ce="0a4f113b", qop=auth, nc=00000001
Content-Type: application/sdp
Allow: INVITE, INFO, PRACK, ACK, BYE, CANCEL, OPTIONS, NOTIFY, REGISTER, SUBSCRIBE, REFER,
PUBLISH, UPDATE, MESSAGE
Max-Forwards: 70
User-Agent: Yealink SIP-T46G 28.82.0.20

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