AudioCodes Mediant 800 - Page 461

CHAPTER19 Coders and Profiles
Mediant 800 Gateway & E-SBC | User's Manual
Parameter Description
'Remote Multiple Early Dialogs'
sbc-multi-early-diag
[IpProfile_
SBCRemoteMultipleEarlyDialo
gs]
Defines the device's handling of To-header tags in call
forking responses (i.e., multiple SDP answers) sent to the
SIP entity associated with the IP Profile. When the SIP
entity initiates an INVITE that is subsequently forked (for
example, by a proxy server) to multiple endpoints, the
endpoints respond with a SIP 183 containing an SDP
answer. Typically, each endpoint's response has a
different To-header tag. For example, a call initiated by the
SIP entity (100@A) is forked and two endpoints respond
with ringing, each with a different tag:
■ Endpoint "tag 2":
SIP/2.0 180 Ringing
From: <sip:100@A>;tag=tag1
To: sip:200@B;tag=tag2
Call-ID: c2
■ Endpoint "tag 3":
SIP/2.0 180 Ringing
From: <sip:100@A>;tag=tag1
To: sip:200@B;tag=tag3
Call-ID: c2
In non-standard behavior (when the parameter is configured
to Disable), the device forwards all the SDP answers with
the same tag. In the example, endpoint "tag 3" is sent with
the same tag as endpoint "tag 2" (i.e., To:
sip:200@B;tag=tag2).
■ [-1] According to Operation Mode = (Default)
Depends on the setting of the 'Operation Mode'
parameter in the IP Group or SRDs table:
✔ B2BUA: Device operates as if the parameter is set
to Disable [0].
✔ Call State-full Proxy: Device operates as if the
parameter is set to Enable [1]. In addition, the
device preserves the From tags and Call-IDs of the
endpoints in the SDP answer sent to the SIP
entity.
■ [0] Disable = Device sends the multiple SDP answers
with the same To-header tag, to the SIP entity. In other
words, this option is relevant if the SIP entity does not
support multiple dialogs (and multiple tags). However,
non-standard, multiple answer support may still be
configured by the SBCRemoteMultipleAnswersMode
parameter.
■ [1] Enable = Device sends the multiple SDP answers
with different To-header tags, to the SIP entity. In other
words, the SIP entity supports standard multiple SDP
answers (with different To-header tags). In this case,
the SBCRemoteMultipleAnswersMode parameter is
ignored.
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