AudioCodes Mediant 1000 User Manual page 604

Parameter
[UseBroadsoftDTG]
Web/EMS: Enable GRUU
[EnableGRUU]
SIP User's Manual
contain the 'tgrp' parameter or if the Trunk Group number is not
defined, then the Inbound IP Routing Table is used for routing the
call.
Below is an example of an INVITE Request-URI with the 'tgrp'
parameter, indicating that the IP call should be routed to Trunk Group
7:
INVITE sip:200;tgrp=7;trunk-
context=example.com@10.33.2.68;user=phone SIP/2.0
Notes:

For enabling routing based on the 'tgrp' parameter, the
UseSIPTgrp parameter must be set to 2.

For IP-to-Tel routing based on the 'dtg' parameter (instead of the
'tgrp' parameter), use the parameter UseBroadsoftDTG.
Determines whether the device uses the 'dtg' parameter for routing
IP-to-Tel calls to a specific Trunk Group.

[0] Disable (default)

[1] Enable
When this parameter is enabled, if the Request-URI in the received
SIP INVITE includes the 'dtg' parameter, the device routes the call to
the Trunk Group according to its value. This parameter is used
instead of the 'tgrp/trunk-context' parameters. The dtg' parameter
appears in the INVITE Request-URI (and in the To header).
For example, the received SIP message below routes the call to
Trunk Group ID 56:
INVITE sip:123456@192.168.1.2;dtg=56;user=phone SIP/2.0
Note: If the Trunk Group is not found based on the 'dtg' parameter,
the Inbound IP Routing Table is used instead for routing the call to the
appropriate Trunk Group.
Determines whether the Globally Routable User Agent URIs (GRUU)
mechanism is used, according to RFC 5627. This is used for
obtaining a GRUU from a registrar and for communicating a GRUU to
a peer within a dialog.

[0] Disable (default)

[1] Enable
A GRUU is a SIP URI that routes to an instance-specific UA and can
be reachable from anywhere. There are a number of contexts in
which it is desirable to have an identifier that addresses a single UA
(using GRUU) rather than the group of UA's indicated by an Address
of Record (AOR). For example, in call transfer where user A is talking
to user B, and user A wants to transfer the call to user C. User A
sends a 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
604
Mediant 600 & Mediant 1000
Description
Document #: LTRT-83310