Yealink SIP-T38G Administrator's Guide

Configuring Security Features
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This chapter provides information for making configuration changes for the following
security-related features:
 Transport Layer Security
 Secure Real-Time Transport Protocol
 Encrypting Configuration Files
The TLS protocol is a commonly-used protocol for providing communications privacy
and managing the security of message transmission. The TLS allows the IP phone to
communicate with other remote parties and connect to the HTTPS URL for provisioning in
a way that is designed to prevent eavesdropping and tampering.
The TLS protocol is composed of two layers: the TLS Record Protocol and the TLS
Handshake Protocol. The TLS Record Protocol completes the actual data transmission
and ensures the integrity and privacy of the data. The TLS Handshake Protocol allows
the server and client to authenticate each other and negotiate an encryption algorithm
and cryptographic keys before data is exchanged.
The following figure illustrates the TLS messages exchanged between the IP phone and
TLS server to establish an encrypted communication channel:
Step1: IP phone sends ―Client Hello‖ message proposing SSL options.
Step2: Server responds with ―Server Hello‖ message selecting the SSL options, sends its
public key information in ―Server Key Exchange‖ message and concludes its part of the
negotiation with ―Server Hello Done‖ message.
Step3: IP phone sends session key information (encrypted with server’s public key) in
the ―Client Key Exchange‖ message.
Step4: Server sends ―Change Cipher Spec‖ message to activate the negotiated options
for all future messages it will send.

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