SIP Profile - Trunk Group Selection

SIP Trunk Group Selection is supported on the IMG 2020. Use the SIP Trunk Group Selection feature if there is a Centralized Routing Model that does not require the IMG 2020 to perform routing decisions. Routing calls based on the Trunk Group parameter is accomplished in this object. The SIP Trunk Group Selection object gives the IMG 2020 the ability to select incoming or outgoing trunk groups and route calls based on the tgrp parameters presented in either the R-URI Header or the Contact Header. The various fields are displayed in the Web GUI Page screen capture below. The SIP Trunk Group Selection pane is created under the SIP Profile (SGP) Pane and its settings are disabled by default.

Web GUI Pane

Dialogic > Profiles > SIP Profile (SGP) > New SIP Trunk Group Selection

Open

Maximum Objects

One SIP Trunk Group Selection object per SIP Profile (SGP) object

Related Topics and Dependencies

SIP Profile - SGP 

Field Descriptions

The chart below displays which fields can be modified depending on the SIP Trunk Group Selection Type. As shown below the Outgoing Trunk Group (OTG) and Destination Trunk Group (DTG) are mutually exclusive. If trying to route on the OTG/DTG, the TGRP fields will show Not Used and vice-versa.

Type

Select from a drop down menu the following selections:

Disabled (Default) - Feature is disabled. All fields will default to Not Used.

OTG/DTG - As shown in the chart above, the first three fields can be set to either enabled or disabled.

TGRP (RFC 4904) - As shown in the chart above, the last three fields can be set to enabled or disabled. 

OTG /DTG Selected (Outgoing Trunk Group)/(Destination Trunk Group)

Use OTG for Incoming Channel Group Selection

Disabled (default) - Field not used or disabled.

Enabled - When the OTG (Outgoing Trunk Group) field is included in the From: header, the IMG 2020 will use this trunk group as the incoming trunk group to determine which incoming DPE table and route table to use. The OTG will also be added to the From: header in an outbound SIP INVITE message but the OTG will have the A side trunk group name. The IMG 2020 extracts the OTG from the SIP From: header and passes it in the Initial Setup. If an OTG is found, the IMG 2020 will use that channel group instead of the one that came from the lookup table in the SIP process.

Use DTG for Outgoing Channel Group Selection

Disabled (default) - Field not used or disabled.

Enabled - When the DTG is received in the request-URI the IMG 2020 will skip the mid-call router and use the DTG that was received as the outbound channel group. When the IMG 2020 is about to perform routing for the outbound side, it will look for the DTG from the same location as the Calling Party Number. If the DTG is valid, the call will then use the channel group that corresponds to that DTG instead of performing a routing lookup.

Apply OTG to the outbound SIP Invite

Disabled (default) - Field not used or disabled.

Enabled - On an outgoing invite, the OTG (Outgoing Trunk Group) that was received from the incoming call will take precedence over the internal IMG 2020 incoming Channel group name if it was a SIP call (for any other inbound protocol, the OTG would be the incoming Trunk Group Name). This OTG is then appended in the From: header of the outbound invite.

TGRP (RFC 4904) Selected

Use ingress tgrp for Incoming Channel Group Selection

Disabled (default) - Field not used or disabled.

Enabled - SIP will parse the Contact Header field and look fortgrp=(originating tgrp) and trunk-context fields. If the parsing succeeds, the IMG 2020 will use the trunk group (tgrp) information to route the call. In the diagram below the inbound Contact Header has tgrp=TG3_IN. When the IMG 2020 looks at the routing tables it routes the call to TG3_OUT.

Open

Use egress tgrp for Outgoing Channel Group Selection

Disabled (default) - Field not used or disabled.

Enabled - SIP will parse the R-URI message and look fortgrp=(destination tgrp) and trunk context fields. If the parsing succeeds, the IMG 2020 will bypass the routing tables and use that trunk group as the outbound channel group. In the diagram below the R-URI message has the tgrp=TG2_OUT. The IMG 2020 bypasses the Routing Tables and send the call out TG2_OUT.

In the above case the following is true:

The incoming trunk group (tgrp) that was received in the incoming call would take precedence over the internal IMG 2020 incoming Channel group if it was SIP only. Any other inbound protocol the tgrp (originating trunk group) would be the incoming Trunk Group Name.   

Apply ingress tgrp to Outbound SIP Invite

Disabled (default) - Field not used or disabled

Enabled - SIP will parse the Contact Header field looking fortgrp=and context header fields. Both the originating tgrp and context header found in the contact header will be passed on into the Contact Header in the Outbound SIP INVITE message.

Additional Information

• If the incoming SIP message has either the tgrp or trunk-context parameters, the IMG 2020 will treat this as No Trunk Group Parameter (tgrp) in the message.

• If the incoming protocol is SIP, the originating trunk group parameter in the outbound contact header will be the same as in the contact header of the incoming SIP message.

• If inbound protocol is something other than SIP, the originating trunk group parameter in the Contact Header for the outbound message will be the incoming trunk group.

• If the inbound Trunk Group is non-SIP, the outbound trunk-context value will default to the IMG 2020 IP Address.