Yealink SIP-T21 E2 Administrator's Guide

Appendix
1057
Method
Supported
Notes
PUBLISH
Yes
SIP Header
The following SIP request headers are supported:
Note
Method
Supported
Notes
Accept
Yes
Alert-Info
Yes
Allow
Yes
Allow-Events
Yes
Authorization
Yes
Call-ID
Yes
Call-Info
Yes
Contact
Yes
Content-Length
Yes
Content-Type
Yes
CSeq
Yes
Diversion
Yes
History-Info
Yes
Event
Yes
Expires
Yes
From
Yes
Max-Forwards
Yes
Min-SE
Yes
P-Asserted-Identity
Yes
P-Preferred-Identity
Yes
Proxy-Authenticate
Yes
Proxy-Authorization
Yes
In the following table, a “Yes” in the Supported column means the header is sent and properly
parsed.

Yealink SIP-T21 E2 Specifications

General

Brand	Yealink
Model	SIP-T21 E2
Category	IP Phone
Language	English