Yealink SIP-T38G Administrator's Guide

Administrator’s Guide for SIP-T3xG IP Phones
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3. Enter the desired value (0-63) in the SIP QoS field.
4. Click Confirm to accept the change.
The web user interface pops up a dialog box to prompt that the settings will take
effect after reboot.
5. Click OK to reboot the IP phone.
Network Address Translation (NAT) is essentially a translation table that maps public IP
address and port combinations to private IP address and port combinations. This
reduces the need for a large amount of public IP addresses. The NAT feature ensures
security since each outgoing or incoming request must go through a translation process.
But in the VoIP environment, NAT breaks end-to-end connectivity.
NAT Traversal
NAT traversal is a general term for techniques that establish and maintain IP
connections traversing NAT gateways. It is typically required for client-to-client
networking applications, especially for VoIP deployments. STUN is one of the NAT
traversal techniques supported by the IP phones.
STUN (Simple Traversal of UDP over NATs)
STUN is a network protocol, which is used in NAT traversal for applications of real-time
voice, video, messaging, and other interactive IP communications. The STUN protocol

Yealink SIP-T38G Specifications

General

Expansion module support	Yes
Ethernet LAN (RJ-45) ports	2
Keypad number of keys	48
Touchscreen	-
Display resolution	480 x 272 pixels
Display number of colors	16.78 million colors
Lines quantity	- lines
Phonebook capacity	1000 entries
Number of VoIP accounts	6
Voice codecs	G.711, G.722, G.723.1, G.726
Bluetooth	No
Security algorithms	802.1x RADIUS, HTTPS, SSL/TLS
AC adapter input voltage	100 - 240 V
AC adapter output voltage	5 V
Power consumption (typical)	4.6 W
Operating relative humidity (H-H)	10 - 95 %
Handset type	Wired handset
Product type	IP Phone
Product color	Black
Compliance industry standards	IEEE 802.3af
Number of handles included	1 pc(s)

Weight and Dimensions

Depth	204 mm
Width	273 mm
Height	42 mm
Weight	1050 g