Description:
SIP Trunk Group Selection is supported on the IMG which is designed using RFC 4904. Use the SIP Trunk Group Selection feature if you have a Centralized Routing Model and do not require the IMG to perform routing decisions. Routing calls based on Trunk Group parameter is accomplished in this pane. The feature ‘Support of Trunk Group Parameters’ gives the IMG the ability to select incoming or outgoing trunk groups and route calls based on the “tgrp” parameters presented in either the R-URI or Contact Header. The selection are shown in the ClientView Pane screen capture below. The SIP Trunk Group Selection pane is created under the SIP SGP Pane and its settings are disabled by default.
Accessing this Pane:
Dialogic IMG EMS -> Logical IMG -> Profiles -> SIP SGP -> SIP Trunk Group Selection
Maximum Objects:
1 per SIP SGP object
Related Topics:
IMG 1010 - SIP Profile - 10.5.3
ClientView Pane:
The SIP Trunk Group Selection object is created under the SIP SGP object. When creating the SIP SGP object the ID defaults to ID:0. This is the default SIP SGP object and when the ID=0 then none of the fields in the SIP SGP object as well as any objects created below this SIP SGP object can be edited. To be able to edit the SIP SGP profile along with any objects beneath change the ID of the SGP object to something other than zero.
Field Descriptions:
The chart below will displays which fields can be edited depending on the SIP Trunk Group Selection Type. As shown below the OTG and DTG are mutually exclusive. If trying to route on the OTG/DTG, the TGRP fields will show Not Used and vice-versa.
Type | Disable | OTG/DTG | TGRP (RFC4904) |
Use OTG for Incoming Channel Group Selection | Not Used | Disabled/Enabled | Not Used |
Use DTG for Outgoing Channel Group Selection | Not Used | Disabled/Enabled | Not Used |
Apply OTG to Outbound SIP Invite | Not Used | Disabled/Enabled | Not Used |
Use ingress tgrp for Incoming Channel Group Selection | Not Used | Not Used | Disabled/Enabled |
Use egress tgrp for Outgoing Channel Group Selection | Not Used | Not Used | Disabled/Enabled |
Apply ingress tgrp to Outbound SIP Invite | Not Used | Not Used | Disabled/Enabled |
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 the first three fields can be set to either enabled or disabled.
TGRP (RFC4904)- As shown in the chart the last three fields can be set to enabled or disabled.
OTG (Outgoing Trunk Group)/DTG (Destination Trunk Group) Selected
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 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 and the OTG will have the A side trunk group name. The IMG extracts the OTG from the SIP "From" header and passes in the Initial Setup. If an OTG is found, the IMG will use that channel group instead of the one that came from the lookup table in the SIP process.
Use the 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 will skip the mid-call router and use the DTG that was received as the outbound channel group. When the IMG 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 the 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 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 for ‘tgrp=’ (originating tgrp) and trunk-context fields. If the parsing succeeds, the IMG 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 looks at the routing tables it routes the call to TG3_OUT.
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 for ‘tgrp=’ (destination tgrp) and trunk context fields. If the parsing succeeds, the IMG 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 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 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 for ‘tgrp=’ 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 incoming SIP message has only either the tgrp or trunk-context parameters, IMG 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 IP Address.