Yealink SIP-T21 E2

Configuring Basic Features
571
100 Reliable Retransmission
As described in RFC 3262, 100rel tag is for reliability of provisional responses. When present in
a Supported header, it indicates that the IP phone can send or receive reliable provisional
responses. When present in a Require header in a reliable provisional response, it indicates that
the response is to be sent reliably.
Example of a SIP INVITE message:
INVITE sip:1024@pbx.test.com:5060 SIP/2.0
Via: SIP/2.0/UDP 10.3.6.197:5060;branch=z9hG4bK1708689023
From: "1025" <sip:1025@pbx.test.com:5060>;tag=1622206783
To: <sip:1024@pbx.test.com:5060>
Call-ID: 0_537569052@10.3.6.197
CSeq: 2 INVITE
Contact: <sip:1025@10.3.6.197:5060>
Authorization: Digest username="1025", realm="pbx.test.com", nonce="BroadWorksXi5stub71Ts2nb05BW",
uri="sip:1024@pbx.test.com:5060", response="f7e9d35c55af45b3f89beae95e913171", algorithm=MD5,
cnonce="0a4f113b", qop=auth, nc=00000001
Content-Type: application/sdp
Allow: INVITE, INFO, PRACK, ACK, BYE, CANCEL, OPTIONS, NOTIFY, REGISTER, SUBSCRIBE, REFER, PUBLISH,
UPDATE, MESSAGE
Max-Forwards: 70
User-Agent: Yealink SIP-T46G 28.81.0.25
Supported: 100rel
Allow-Events: talk,hold,conference,refer,check-sync
Content-Length: 302
Procedure
100 Reliable Retransmission can be configured using the following methods.
Central Provisioning
(Configuration File)
<MAC>.cfg
Configure the 100 reliable
retransmission feature.
Parameter:
account.X.100rel_enable
Web User Interface
Configure the 100 reliable
retransmission feature.
Navigate to:
http://<phoneIPAddress>/servlet?p
=account-adv&q=load&acc=0