AudioCodes Mediant 800 - Interworking SIP REFER Messages

CHAPTER30 SBC Overview
Mediant 800 Gateway & E-SBC | User's Manual
Parameter
Value
SIP Header Present
in incoming SIP
Message
Device Action
IP Header Present
in outgoing SIP
Message
'Diversion
Header Mode'
= Add
'History-Info
Header Mode'
= As Is
Not
present
Present Diversion added from
History-Info
Present Present
'Diversion
Header Mode'
= As Is
'History-Info
Header Mode'
= Add
Present Not
present
History-Info added from
Diversion
Present Present
'Diversion
Header Mode'
= Add
'History-Info
Header Mode'
= Remove
Not
present
Present Diversion added from
History-Info
History-Info removed
Present Not
present
'Diversion
Header Mode'
= Remove
'History-Info
Header Mode'
= Add
Present Not
present
History-Info added from
Diversion
Diversion removed
Not
present
Present
'Diversion
Header Mode'
= Remove
'History-Info
Header Mode'
= Remove
Present Present Both removed Not
present
Not
present
Interworking SIP REFER Messages
The device supports interworking of SIP REFER messages. SIP UAs may support different
versions of the REFER standard while others may not even support REFER.
This feature supports the following:
■ Attended, unattended, and semi-attended call transfers
■ Sending INVITE, REFER-notifications, BYE, PRACK and Session Timer on behalf of peer
PBXs
■ Advanced routing rules for the new, initiated INVITE
■ Forwarding early media after REFER while attempting to avoid transcoding (by sending
session update)
■ Interoperate with environments were different SIP UAs lack basic SIP functionality such as re-
INVITE, UPDATE, PRACK, Delayed Offer, re-INVITE without SDP
■ Session updates after connect to avoid transcoding
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