Yealink SIP-T48G Administrator's Manual page 274

Microsoft Lync Edition Administrator's Guide for SIP-T2_Series and T4_Series IP Phones
Method
Accept
Alert-Info
Allow
Allow-Events
Authorization
Call-ID
Call-Info
Contact
Content-Length
Content-Type
CSeq
Diversion
History-Info
Event
Expires
From
Max-Forwards
Min-SE
P-Asserted-Identity
P-Preferred-Identity
Proxy-Authenticate
Proxy-Authorization
RAck
Record-Route
Refer-To
Referred-By
Remote-Party-ID
Replaces
Require
Route
262
Supported
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Notes