User Manual

Yealink Skype for Business HD IP Phones Administrator Guide
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 IDEA-CBC-SHA
 DHE-DSS-RC4-SHA
 RC4-SHA
 RC4-MD5
 EXP1024-DHE-DSS-DES-CBC-SHA
 EXP1024-DES-CBC-SHA
 EDH-RSA-DES-CBC-SHA
 EDH-DSS-DES-CBC-SHA
 DES-CBC-SHA
 EXP1024-DHE-DSS-RC4-SHA
 EXP1024-RC4-SHA
 EXP1024-RC4-MD5
 EXP-EDH-RSA-DES-CBC-SHA
 EXP-EDH-DSS-DES-CBC-SHA
 EXP-DES-CBC-SHA
 EXP-RC4-MD5
The following figure illustrates the TLS messages exchanged between the Skype for Business
phone and TLS server to establish an encrypted communication channel:
Step1: Skype for Business 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: Skype for Business phone sends session key information (encrypted by 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.
Skype for Business phones can encrypt SIP with TLS, which is called SIPS. When TLS is enabled
for an account, the SIP message of this account will be encrypted, and a lock icon appears on
the LCD screen after the successful TLS negotiation.