# Editing the trunk groups

The trunk group configuration determines the connection properties of the network interfaces connected to the communication server. A trunk group groups together the network interfaces of the same type (trunk group type).

The trunk group is the key element for call traffic with the network. The trunk group configuration is allocated important routing and identification functions, essentially for incoming traffic. Depending on the type of trunk group not all settings are available.

Table 1. General trunk group settings
Parameter | Explanation | ISDN/CAS | SIP | Analogue
Trunk groups | Identification number of the trunk group |  |  |
Name | Name of the trunk group |  |  |
Type of trunk group | Type of the trunk group |  |  |
Maximum incoming calls / Maximum outgoing calls | No further incoming/outgoing calls are routed via this trunk group once the set limit is reached. This is signalled to the caller by means of the congestion tone. This allows you to ensure that lines remain free for outgoing/incoming calls. |  |  |
Maximum simultaneous connections | Once the set limit is reached, no more connections are set up via this trunk group. |  |  |
Total B channels | Shows the number of available call channels. |  |  |
Call distribution element | Linked call distribution element. Calls are routed to this call distribution element either if no direct dialling plan is linked or if no suitable direct dialling number is found and the Network type setting is set to Public. |  |  |
DDI (DID) plan | Connected DDI plan |  |  |
DDI(DID) Cut | This setting lets you truncate the number of digits that do not belong to the direct dialling number, starting from the left. |  |  |
DDI (DID) lookup | Left to right: The call number is compared with the direct dialling numbers, starting from the left (default). Right to left: The call number is compared with the direct dialling numbers, starting from the right (default setting for France). |  |  |
Trunk line selection mode | Linear: Exchange lines for outgoing calls are occupied from back to front (large numbers first). This means the call charges tend to accumulate on the network interfaces with larger numbers. Cyclic: The system detects the exchange line on which the last call was made and tries to make the next call on the next exchange line. Charges are, thus, evenly distributed to all network interfaces. |  |  |
Transit route | External calls coming in via this trunk group and leaving the communication server (transit connections), are again routed via the transit route selected here. |  |  |
Region | Here you can set a specific region for this trunk group. |  |  |
Emergency location | Here you can assign any of the defined emergency location data sets to this trunk group. When an emergency number out of the public emergency number list ( =we) is dialled, the system reacts with specific actions: The location of the caller is sent to the provider, an emergency response team is informed, alarms are issued and logs are updated. For more information, see "Emergency service support". |  |  |
Emergency location protocol | The protocol for sending the emergency location identifier can be selected here. This setting is dependant on the networking type, the provider, and the country. The settings are: No location identifier CLIP ('From', 'PAI', 'Calling Pty No.') PANI (P-Asserted-Network-Info) PAI (P-Asserted-Identity) |  |  |
Municipality Identifier protocol | The protocol for sending the municipality identifier can be selected here. This setting is dependant on the networking type, the provider, and the country. The settings are: No Municipality identifier Append Municipality Identifier to called number |  |  |

Table 2. Networking
Parameter | Explanation | ISDN/CAS | SIP | Analogue
Network type | This setting determines the trunk group controls the way in which incoming calls are distributed: First the direct dialling plan is searched for a matching direct dialling number for the call number of the incoming call. Public: If no direct dialling number matches, the call is routed to the linked call distribution element Call distribution element) Private: If no direct dialling number matches, the call is routed to the internal numbering plan. |  |  |
Protocol | DSS1 is the ISDN protocol for the public network; QSIG is a standardised signalling protocol for networking several communication systems into a private network (PISN). |  |  |
QSIG extension | The extended QSIG protocol is supported. This means a number of features (for example, a number of function codes) can be operated throughout the private network. |  |  |
Ring if NPI is 'Unknown' | In certain network constellations the numbering plan identifier for a call number is not defined for incoming calls (NPI=Unknown). The communication server therefore lacks the criterion to know whether the call should be signalled as external (NPI=E.164) or internal (NPI=PNP). Internal: A call with the NPI attribute Unknown is offered with the internal ringing pattern. External: A call with the NPI attribute Unknown is offered with the external ringing pattern and the CLIP is preceded by the exchange access prefix with hyphen. |  |  |
Cut CLIP | A digit sequence can be configured here. If the sequence matches the initial digits of the CLIP number received, the digits will be truncated. On a private network this setting is used to cut superfluous '0'. |  |  |
Overwrite NPI | Lets you overwrite the NPI (numbering plan identifier) for the call number of an incoming call. The public network uses the E.164 numbering plan identifier; the private network, the PNP (Private Numbering Plan) numbering plan identifier. Leave the setting on the default setting No, providing the communication server is not a private network node. |  |  |
Incoming call, ring back tone | Lets you specify whether the communication server itself should generate the ring back tone for incoming calls. In the public network the ring back tone is supplied by the local exchange and does not have to be generated by the communication server. So leave the setting on the default setting Do not generate, provided the communication server is not a private network node. |  |  |
Outgoing call, ring back tone | Lets you specify whether the communication server itself should generate the ring back tone for outgoing calls. In the public network the ring back tone is generated by the local exchange and does not have to be generated by the communication server. So leave the setting on the default setting Do not generate, provided the communication server is not a private network node. |  |  |
Early media support | This setting is only relevant in connection with Lync. The ISDN interface is linked to a Lync endpoint. The ISDN interface is not linked to a Lync endpoint. |  |  |
Block dialling only | Settings for trunk groups with ISDN interfaces - PRI Lite (New Zealand): The trunk group contains ISDN interfaces (PRI Lite). The trunk group does not contain any ISDN interface (PRI Lite). Note: One and the same trunk group cannot contain both PRI-Lite and BRI interfaces. |  |  |
B channel negotiation | Settings for trunk groups with ISDN interfaces - PRI Lite (New Zealand): The trunk group does not contain any ISDN interface (PRI Lite). The trunk group contains ISDN interfaces (PRI Lite). Note: One and the same trunk group cannot contain both PRI-Lite and BRI interfaces. |  |  |

## Fax server

The following settings are relevant only if you are using the fax server integrated on the applications card (Mitel 470 only).

Table 3. Fax server settings
Parameter | Explanation | ISDN/CAS | SIP | Analogue
Base number | For digital network interfaces: The base number is the call number for the direct dial range for the fax destinations without the direct dial portion. Enter the base number in canonical format. Example: number range for fax destinations (in international format): 0041 32 621 9470 to 0041 32 621 9479 Direct dial portion: 9470 to 9479 Base number (to be entered here): +41 32 621 For analogue network interfaces: Enter the complete external call number of the fax extension in canonical format as the base number. Example: +41 32 621 9470 |  |  |
DDI prefix | If the direct dial portion comprises a prefix (e.g. a national prefix), enter the prefix here. Example: Number range for fax destinations (international format): 0041 32 621 9470 to 0041 32 621 9479 Direct dial portion: 0326219470 to 0326219479 Direct dial prefix (to be entered here): 0 Leave the entry blank if the direct dial portion does not comprise a prefix. |  |  |

## Features

Table 4. Features
Parameter | Explanation | ISDN/CAS | SIP | Analogue
Public network features:
Redirect in public network (PARE) | Exchange-to-exchange CFUs are routed to the public network, which means that no B channels are seized in the communication server. This feature is offered by the network provider as a PARE supplementary service for point-to-point operation and as Call Deflection (CD) in point-to-multipoint operation. Many network operators provide the service as part of their basic offer; with some operators you need to request its activation. The called user in the public network sees the caller's ID as well as information on which internal user redirected the call. This setting must also be made in the ( =cb) permission set. |  |  |
Hold allowed in public network (HOLD) | If an internal user puts a call with an external party on hold, the call is held locally and the busy B channel remains busy. If the internal user then dials an external phone number, the communication server transfers the locally held call to the exchange by activating the Hold supplementary service with the network provider. The busy B-channel is then freed up. Many network operators provide the service as part of their basic offer; with some operators you need to request its activation. Available only in point-to-multipoint operation. |  |  |
Three-party in public network (3PTY) | If two conference participants are public network users, the conference node is transferred to the exchange. One busy B-channel is then freed up. Many network operators provide the service as part of their basic offer; with some operators you need to request its activation. Available only in point-to-multipoint operation. |  |  |
Explicit Call Transfer (ECT) | If an internal user hands over a connection with an external user to another external user, the connection is transferred entirely to the exchange. The two busy B-channels are then freed up. Many network operators provide the service as part of their basic offer; with some operators you need to request its activation. Available only in point-to-multipoint operation. |  |  |
Exchange supports “Identity of Charge” | The communication server also sends the call charge identity when call forwarding is transferred to the exchange (PARE, CD). This ensures that call charge information is correctly logged in the communication server. Many network operators provide the service as part of their basic offer; with some operators you need to request its activation. |  |  |
Allow path replacement | This setting is significant only if you are operating an A2P2-certified third-party application on the communication server and if it is connected to the communication server via QSIG. When the third-party application is transferring a call for user A to user B, the B channels no longer used between the communication server and the third-party application should be released once again. Note: This function is not to be confused with the QSIG Path Replacement according to ETS 300258 standardised within the ETSI. |  |  |
Notification:

Table 5. Notification
Parameter | Explanation | ISDN/CAS | SIP | Analogue
Send notifications | Send current state of a connection to the public network as a notification. Allows the connection status to be displayed for external users. The feature must be supported by the public network provider. |  |  |
Send redirection information | Redirecting information is sent to the public network. Allows the redirecting information to be displayed in the case of external users. The feature must be supported by the public network provider (special arrangement). |  |  |
Send ECT information | After the call transfer to a different internal or external user sends the user's CLIP to the exchange. Allows the CLIP to be displayed correctly to the external user after the call transfer. Note: Sending ECT information can cause problems in the case of some network operators. |  |  |
Send first/last mailbox information | This setting is significant only in private QSIG networking or if voice mail is connected via QSIG. Situation: User A has redirected to PISN user B; user B has redirected to his voice mailbox. The response depends on the user setting Forward call to last mailbox in the call forwarding chain set for the user (Configuration / User / User list view). A call to user A is in any case forwarded to the voice mailbox of user B or to the voice mailbox of the last user in the chain. |  |  |

Table 6. Mobile/external phone integration
Parameter | Explanation | ISDN/CAS | SIP | Analogue
Allow CLIP authentication even if CLIP is not screened | Allows automatic authentication of the integrated mobile/external phone via analogue or SIP network interfaces. |  |  |
Allow enhanced functionality for direct incoming calls | Allows the use of the extended mobile phone functionality if mobile phone integration is achieved using separate lines to the GSM provider (depends on the provider). |  |  |

## Call identification information

The CLIP numbers of outgoing calls can be influenced by the settings in the trunk group configuration. The link between the settings for outgoing call identification at the user's and the present settings are shown in a graphical overview (hyper link after this table).

Creating call identification information for outgoing calls Diagram on the creation of call identification information for outgoing calls.

Table 7. Outgoing Calling line identification presentation (CLIP)
Parameter | Explanation | ISDN/CAS | SIP | Analogue
CLIP automatic | The communication server automatically sets the NPI and TON attribute. The communication server adopts the Numbering plan identifier (NPI) setting as its NPI attribute and as its TON attribute the Number type (TON) setting. |  |  |
Numbering plan identifier (NPI) | The numbering plan is used to analyse numbers and allocate them to an addressable destination. E.164: Thus type of numbering type is used in a public network that is defined and standardised by ITU-T. PNP: This type of numbering plan is used in the private sector (PNP=Private Numbering Plan). The internal numbering plan of a communication server or a private network is also of the type PNP, as is a private numbering plan offered by public network operators. |  |  |
Type of number (TON) (for numbering plan type = E.164) | The Type of number (TON) must be made to match the CLIP number and the dialling-in number format (the examples in brackets are dialling-in numbers that refer to the call number “+41 32 624 1344”): Unknown: (standard setting): The CLIP number is not entered according to a specified format (example: “44”, “1344”, “0326241344”. If you select this format, you need to match the CLIP number with the user’s dialling-in number. Subscriber: Enter the CLIP number with this setting in accordance with the user number format: “6241344”. National: (Recommendation): Enter the CLIP number with this setting in accordance with the national format: “326241344”. International: Enter the CLIP number with this setting in accordance with the international format: “41326241344”. Use National or International and the corresponding dialling-in numbers if you have activated Special Arrangement (CLIP not screening) with your network provider. |  |  |
Type of number (TON) (for numbering plan identifier PNP) | Unknown: The TON attribute is not set. Level 0: Regional number: Addresses destinations within the same region (Level 0). Example: 3131 Level 1: Regional number with a region prefix Addresses destinations in all Level 0 regions, located in the same, higher-order region (Region Level 1). Example: 60 3131. Level 2: Regional number with a Level 1 region prefix and another region prefix. Addresses destinations in all Level 1 regions, located in the same, higher-order region (Region Level 2). Example: 42 60 3131. |  |  |
CLIP number | If required, you can enter here a fixed CLIP number that is common to all outgoing calls made via this trunk group. This CLIP is also included if there is no dialling-in number for the user who is dialling an outgoing call and the communication server therefore cannot create the CLIP number based on the dialling-in number. If the entry is left blank, the communication server does not send a CLIP number and the network provider enters the trunk connection’s main call number. Enter the CLIP number according to the dialled number type (see settings Type of number (TON). |  |  |
Restrict CLIP (CLIR) | The call identification is suppressed for outgoing calls via this trunk group. |  |  |
CLIR for redirection | Situation: A user with an active CLIR has redirected a call to the public network. Call identification during the call phase is suppressed when a call is redirected . Call identification during the call phase is not suppressed when a call is redirected. This setting is effective for all calls redirected via this trunk group to the public network. |  |  |
Restrict call identification while connected (COLR) | Call identification during the call is suppressed for outgoing calls via this trunk group. |  |  |
COLR for redirection | Situation: A user with an active COLR has redirected a call to the public network. Call identification during the call is suppressed when the call is redirected. Call identification during the call is not suppressed when the call is redirected. This setting is effective for all calls redirected via this trunk group to the public network. |  |  |

Table 8. Call identification in a networked environment (Transit CLIP)
Parameter | Explanation | ISDN/CAS | SIP | Analogue
Transit CLIP format | CLIP format for transit connections in networks: National: The CLIP for transit connections is formed in accordance with E.164/national with incoming national calls and in accordance with E.164/international with international calls. International: The CLIP for transit connections is formed in accordance with E.164/international. Unknown' with national prefix': The CLIP for transit connections with incoming national calls is formed in accordance with E.164/Unknown + National prefix + Transit exchange prefix and with incoming international calls in accordance with E.164/Unknown + International prefix + Transit exchange prefix. Unknown' with international prefix‘ The CLIP for transit connections with incoming national and international calls is formed in accordance with E.164/Unknown + International prefix + Transit exchange access prefix. |  |  |
Transit exchange access prefix | Enter here the transit exchange access prefix for the settings Transit CLIP format = 'Unknown' with national prefix and Transit CLIP format = 'Unknown' with international prefix. |  |  |
Send incoming CLIP for trunk-trunk connections | This setting takes effect when a call is set up from an integrated mobile/external phone or a PISN user with a external target number (both are trunk-to-trunk situations). The DDI number of the integrated mobile /external phone user or of the PISN user is presented to the called party. If they do not have a specific DDI number, the main number of the communication server is presented. |  |  |
Use CLIP for user DDI(DID) lookup | Activate for transit calls from MiCC to send out the correct CLIP when an outgoing call is made. |  |  |

## Collect calls

The following settings are relevant only for the Brazilian sales channel.

Table 9. Collect call
Parameter | Explanation | ISDN/CAS | SIP | Analogue
Handling of collect calls | Lets you define the response to a collect call request. Reject all collect calls: Collect calls are rejected Accept all collect calls: Collect calls are handled as normal calls. The user can manually reject a collect call by hanging up. Depending on destination: The configuration of the ( =cb) permission set of the user or ( =2t) user group is decisive. Default values: ISDN/CAS and analogue trunk group: Depends on destination SIP trunk group: Allow all collect calls Note: Collect calls cannot be distinguished from normal calls via SIP network interfaces. This is why with the setting Reject all collect calls both collect calls and normal calls are rejected. With the setting Depending on destination it is assumed that each call is a collect call and is handled according to the settings for the user group ( =2t) and for the user ( =0b). |  |  |

Parent topic: Incoming call routing
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