Trunks
A trunk is an interface between two telephony switching systems. Depending on the services available from your local telephony carrier, a trunk can connect your Bright Pattern Contact Center switch directly to a carrier’s voice-over-IP (VoIP) network or to a traditional TDM system via an IP-PSTN gateway.
To work with trunks, select the Trunks option from the Phone System menu.
Note: Bright Pattern Contact Center software can process DTMF out of band as RFC2833 or (less preferred) in-band.
The following at-a-glance details are listed for each trunk:
- Name
- Type
- Number
- Domain
- Carrier
- Tenant
- Prefixes
- Enabled
- Registered
How to Add a Trunk
- Click the Add trunk button (+) at the bottom of the trunks list.
Click the "+" to add a trunk - Click the "+" to add a trunk
- Choose from one of four trunk types: Single Tenant PBX, In-Cloud PBX, Single Tenant PSTN, or Multi-Tenant PSTN.
Select trunk type - Select trunk type.
- Fill in the settings in each of these tabs: Properties, Authentication, Registration, Advanced, and Access Numbers.
Screen Properties
Trunk properties are described as follows for each tab: Properties, Authentication, Registration, Advanced, and Access Numbers. Note that the properties vary according to the trunk type selected; you may not see all the properties listed below, and that is OK.
Properties tab
Name
This is the name that identifies this trunk within the system configuration. A mandatory field, this name is used for internal identification purposes and is not transmitted over the public network.
Type
Type is the trunk type, which is set when you add a new trunk and select the trunk type.
There are four trunk types:
- Single Tenant PBX - One contact center using the private branch exchange (PBX) phone system or SBC
- In-Cloud PBX - Cloud-based PBX phone system (i.e., softphones)
- Single Tenant PSTN - One contact center using the public switched telephone network (PSTN) (i.e., landline phone system)
- Multi-Tenant PSTN - Multiple contact centers using the public switched telephone network (PSTN) (i.e., landline phone system)
Carrier
Carrier is the name of the carrier company. It will appear in the usage reports.
Enabled
Enabled indicates whether this trunk is currently enabled or disabled. By default, trunks are enabled. If you disable a trunk, the system will not use it for outbound dialing; possible incoming interactions via this trunk will be rejected with an error message. This can be used, for example, to let the carrier finish provisioning of their side of the trunk or as a manual failover from a malfunctioning route. To disable the trunk, deselect the checkbox.
Region
Select the geographic region for the trunk, or click edit regions to change or add regions to the selector. Here you will find two entries: the main location and a remote location. One of the regions will be marked as default. Generally, Bright Pattern Contact Center servers, SIP processors, and RTP processors will prioritize connecting to each other locally, which is why region selection is important.
Trunks are associated with regions, as well as hosts. The region selector is added to Host Properties in the Hosts & Components section of Service Provider. This implementation only has an effect on SIP and RTP processors and is ignored for servers.
Tenants, when created, are associated with a region by default. The tenant Region selector is used to initialize user region at the time of creation.
The ability to select a non-default region per user is enabled by selecting the checkbox Enable multiple regions in the Features tab of Tenants. When this checkbox is selected, the region in the user’s configuration is shown as "read-only."
If no region is defined, the region selector is not shown for users, but shown in Trunks>Regions and Hosts & Components, with a link to edit. If one region is defined, it is designated the default and is automatically selected when new tenants, hosts, or trunks are created. Changing default regions does not affect existing users or tenants.
When the first region is defined, the system automatically assigns it to all tenants, tenant users, hosts, and trunks. When a region is deleted, the system automatically reassigns all users, hosts, and tenants to the default region; the default region cannot be deleted.
Note: For SIP trunks with outbound registrations, only SIP processors associated with the same region as the trunk will be used to initiate/perform the registrations. If all SIP processors for a region are down or taken out of service; trunk registration will not happen.
Dial prefixes that select this trunk
This is the list of prefixes associated with this trunk. If a number dialed when making an outbound call begins with any of the prefixes specified here, this trunk will be selected for making the outbound call. To add a prefix, click add. In the dialog box that appears, specify Prefix and, optionally, Cost. Cost is used to decide the least expensive trunk to place a call to numbers with the given prefix.
Prefixes can contain a leading plus (+) sign indicating international calling.
You can use the asterisk symbol (*) as a wildcard for any prefix, thus enabling calls to any outside number to be made via this trunk.
Note that the same prefix may be associated with more than one trunk. In this case, the system will randomly decide which trunk to use for a corresponding outbound call; once trunk capacity is reached, the system will then proceed randomly through the remaining trunks. Note that certain technical limits may affect how quickly trunk capacity is reached. If the cost information for such prefixes is available, the calls will be attempted through the trunks with the lower cost first.
Do not use for Progressive, Predictive and Automatic campaign dialing
This property indicates whether this trunk can be used for making calls associated with the following types of outbound campaigns: Predictive, Progressive, and Automatic. Note that enabling this setting does not restrict the trunk from being used in Preview campaigns (i.e., all trunks may be used for Preview campaigns).
This trunk can set arbitrary Caller ID
This property indicates whether the system can set arbitrary caller IDs for outbound calls on this trunk. If enabled, the tenants using this trunk will be able to use the customer’s number of original service calls as the Caller ID for associated external consultations and transfers. Note that this trunk-level setting reflects the actual technical capabilities of the trunk and should be supported on the carrier side (some carriers may reject calls with arbitrary Caller IDs resulting in failed transfers).
In addition, the ability to use Caller ID relay functions is also controlled by permission, which is set at the tenant level. See section Tenants for more information.
Allow issuing SIP REFER
Select the checkbox for Allow issuing SIP REFER to allow applications such as call transfer.
Enable STIR/SHAKEN attestation on outbound calls
This option is only available for PSTN trunks, and only if a valid STIR/SHAKEN certificate is configured, and the Canonical cluster name (URL) is defined.
When enabled, outbound calls from the trunk are Attested by inserting an "Identity" header into the outgoing SIP INVITE request in these cases:
- Full Attestation (A): for phone numbers provided to the tenant by the service provider.
- Partial Attestation (B): for phone numbers configured by the tenant as caller ID only
- Gateway Attestation (C): for "customer ANI" relay calls and for unknown ANI (calling) numbers from dialer lists
Certificates are made available via a publicly-accessible URL, https://<cluster domain>/sysmgmt/certificates/<certificate name>.pem, that is included as part of the attestation signature, and used by counter-parties for signature verification.
Notes
This free-form text field can be used to store any additional information about this trunk.
Authentication tab
Outgoing Requests > Username
This is the username that will be used for authentication of the outbound call attempts made via this trunk. This information is optional and depends on the policies of the carrier who owns this trunk. If authentication is used, this information shall be provided by the carrier.
Outgoing Requests > Password
This password is what will be used for authentication of the outbound call attempts made via this trunk. This information is optional and depends on the policies of the carrier who owns this trunk. If authentication is used, this information shall be provided by the carrier.
Incoming Requests > Require authentication
This property indicates whether authentication of the incoming interactions attempts received via this trunk will be required. If authentication is necessary, select the checkbox.
Incoming Requests > Username
This username is what will be used for authentication of the incoming interactions attempts received via this trunk. This parameter needs to be specified only if the Require authentication checkbox is selected. If specified, remember that this information must be submitted to the carrier.
Incoming Requests > Password
This password is what will be used for authentication of the incoming interactions attempts received via this trunk. This parameter needs to be specified only if the Require authentication checkbox is selected. If specified, remember that this information must be submitted to the carrier.
Registration tab
Local domain
Local domain is used to match To field in incoming SIP INVITE messages and to write From field in outgoing SIP INVITEs.
Remote domain
Remote domain is used to match From field in incoming SIP INVITE messages and to write To field in outgoing SIP INVITEs.
Note: Upgrading populates both Local and Remote domains from the previous SIP domain field.
Send outbound requests via
Outbound interaction attempts can be made either via SIP domain or a dedicated outbound proxy. Select the option that corresponds to your environment. By default, outbound interaction attempts will be made via SIP domain.
Outbound proxy IP address or hostname
This parameter needs to be specified only if option Send outbound requests via is set to outbound proxy. If you use this setting, specify the IP address of the outbound proxy and if necessary, change the default Port.
Registration type
Registration type is where you select the type of registration for this trunk: static, incoming from carrier, or outgoing to carrier.
If static is selected, no REGISTER requests will be sent or received. If incoming from carrier is selected, the trunk will be expected to register with the system. If outgoing to carrier is selected, REGISTER requests will be sent from the system to the trunk.
Require port of incoming messages to match
Select this option to require the ports of incoming messages to match.
Match Local domain with To domain
Select this option to require the "To" domain for incoming messages to match the Local domain. We always use “Remote Server hostname or IP Address” to match incoming messages with trunks. This option enables additional checks in addition to the IP address.
Match Remote domain with From domain
Select this option to require the "From" domain for incoming messages to match the Remote domain.
This option enables additional checks in addition to the IP address.
Number to be registered
This is the number that will be registered.
Registration interval
The registration interval is specified in seconds. It is essential only for outgoing registration. The default value is 3600 seconds.
Advanced tab
Default country code
This specifies the default country code to be added to the Caller ID/ANI number and/or DNIS number for calls coming in via this trunk in case the received number does not contain any country code.
Long distance prefix
This specifies the long distance prefix to be added to the Caller ID/ANI number and/or DNIS number for outbound calls made by this trunk.
For numbers without leading +
For numbers without a leading "+" sign, select one of these options:
- Numbers may not have a country code, prepend it if necessary
- Numbers may have a long distance prefix, if found, replace it with country code
Add leading + sign
For outbound calls, select this option to add a leading "+" sign.
Replace default country code with long distance prefix
For outbound calls, select this option to replace the default country code with long distance prefix.
When placing calls via this trunk, replace "From" with the registration number
For outbound calls, select this option to replace the "From" with the registration number.
When placing calls…
This setting indicates whether the From parameter of the SIP message shall be replaced with the registration number when making calls via this trunk.
Options
Options presents a key-value list of advanced settings for this trunk in the following format: {“key1” : “value”, “key2” : “value”, … “key N” : “value”} Some of the trunk configuration options can be specific to the VoIP carrier. Bright Pattern Contact Center provides templates for several carriers. To load a template, click Load template and select the carrier from the drop-down list. The Generic Gateway template can be tried in absence of a carrier-specific template. For more information about the Generic Gateway settings, see Bright Pattern Contact Center Advanced Configuration Options, section Trunk. Changing values of these settings without consulting vendor’s technical support is generally not recommended.
Access Numbers tab
List of access numbers
This property lists the access numbers currently associated with this trunk. See Access Numbers for more information. To associate one or more access numbers with this trunk, click the Assign Access Numbers button.