AudioCodes Mediant 800B - Page 1135

Version 7.2 1135 Mediant 800B Gateway & E-SBC
User's Manual 72. Configuration Parameters Reference
Parameter Description
REFER to user C:
REFER sip:C@domain.com SIP/2.0
From: sip:A@domain.com;tag=99asd
To: sip:C@domain.com
Refer-To: (URI that identifies B's UA)
The Refer-To header needs to contain a URI that user C can use to
place a call to user B. This call needs to route to the specific UA
instance that user B is using to talk to user A. User B should provide
user A with a URI that has to be usable by anyone. It needs to be a
GRUU.
 Obtaining a GRUU: The mechanism for obtaining a GRUU is
through registrations. A UA can obtain a GRUU by generating a
REGISTER request containing a Supported header field with the
value “gruu”. The UA includes a “+sip.instance” Contact header
parameter of each contact for which the GRUU is desired. This
Contact parameter contains a globally unique ID that identifies the
UA instance. The global unique ID is created from one of the
following:

If the REGISTER is per the device’s client (endpoint), it is the
MAC address concatenated with the phone number of the
client.

If the REGISTER is per device, it is the MAC address only.

When using TP, “User Info” can be used for registering per
endpoint. Thus, each endpoint can get a unique id – its phone
number. The globally unique ID in TP is the MAC address
concatenated with the phone number of the endpoint.
If the remote server doesn’t support GRUU, it ignores the parameters
of the GRUU. Otherwise, if the remote side also supports GRUU, the
REGISTER responses contain the “gruu” parameter in each Contact
header. The parameter contains a SIP or SIPS URI that represents a
GRUU corresponding to the UA instance that registered the contact.
The server provides the same GRUU for the same AOR and instance-
id when sending REGISTER again after registration expiration. RFC
5627 specifies that the remote target is a GRUU target if its’ Contact
URL has the "gr" parameter with or without a value.
 Using GRUU: The UA can place the GRUU in any header field that
can contain a URI. It must use the GRUU in the following
messages: INVITE request, its 2xx response, SUBSCRIBE request,
its 2xx response, NOTIFY request, REFER request and its 2xx
response.
[IsCiscoSCEMode] Determines whether a Cisco gateway exists at the remote side.
 [0] = (Default) No Cisco gateway exists at the remote side.
 [1] = A Cisco gateway exists at the remote side.
When a Cisco gateway exists at the remote side, the device must set
the value of the 'annexb' parameter of the fmtp attribute in the SDP to
'no'. This logic is used if Silence Suppression for the used coder is
configured to 2 (enable without adaptation). In this case, Silence
Suppression is used on the channel but not declared in the SDP.
Note: The IsCiscoSCEMode parameter is applicable only when the
selected coder is G.729.
User-Agent Information Defines the string that is used in the SIP User-Agent and Server