# Inbound Trunks in phone.systems(TM) Note The instructions below apply specifically to phone.systems(TM) inbound trunks, which are separate from the Inbound Trunks in the main DIDWW user panel - the feature set and setup steps differ. phone.systems(TM) Inbound Trunks receive SIP traffic from third-party VoIP providers and deliver incoming calls into the phone.systems(TM) environment for further processing. Multiple providers can be used, with DIDWW preconfigured as the default. To access and manage your inbound trunks, click **Trunks** in the sidebar menu and select the **Inbound Trunks** tab. [![../../_images/fig156.png](../../_images/fig156.png)](../../_images/fig156.png) **Fig. 1.** Inbound Trunks --- ## Inbound Call Forwarding to phone.systems(TM) When you receive calls from an external VoIP provider, those calls must be forwarded into your phone.systems(TM) workspace. To make this possible, phone.systems(TM) automatically creates a default inbound trunk named Default. You can [edit](#ps3-edit-inbound-trunks), [delete](#ps3-delete-inbound-trunks), or [create](#ps3-inbound-trunk-create) additional inbound trunks as needed. Your VoIP provider must forward SIP traffic to this domain using a SIP URI such as: ``` phonenumber@xxxxxxxxxxxxx.fra.in.phone.systems ``` This SIP URI consists of two components: - **Phone Number in E.164 format** - The phone number receiving the call (for example, `14169233346` for Toronto or `442034116446` for London). This number [must also be added](../Numbers/phone-numbers.html#ps3-add-3rd-party-phone-numbers) to your phone.systems(TM) workspace so that incoming calls can be properly identified and processed. - **Inbound trunk domain** - The unique domain assigned to your inbound trunk (for example, `abcd123456.fra.in.phone.systems`). This domain specifies the destination where phone.systems(TM) expects to receive inbound SIP traffic. For new trunks, the domain includes the selected [POP](#ps3-inbound-trunk-pop). Together, these elements ensure that your VoIP provider correctly delivers inbound calls into the appropriate inbound trunk within phone.systems(TM), enabling your call flows, routing logic and extensions to handle the calls. Note Consult your VoIP provider for instructions on forwarding your DID numbers to the SIP URIs used by phone.systems(TM). ### View Inbound Call Forwarding Trunk Domain Each inbound trunk in phone.systems(TM) is assigned a unique SIP domain used by your VoIP provider when delivering inbound SIP traffic. 1. In the **Inbound Trunks** list, click the **Actions** button next to the trunk you want to view. 2. Select **Edit** to open the **Edit Inbound Trunk** window. [![Actions Menu](../../_images/actions_menu.png)](../../_images/actions_menu.png) **Fig. 2.** Opening the Edit window for an inbound trunk 3. The **Domain** appears in the **Edit Inbound Trunk** form at the top of the **General** section. 4. Click the **copy** icon next to the domain field to copy the value. Important This domain must be used by your VoIP provider when routing inbound calls to your phone.systems(TM) environment. [![Inbound Trunk Domain Field](../../_images/domain_copy.png)](../../_images/domain_copy.png) **Fig. 3.** Copying the inbound trunk domain ### Inbound Trunk POP The **POP** setting selects the DIDWW point of presence (POP) that processes calls for the inbound trunk. Available values are **FRA** (Frankfurt) and **NYC** (New York). New inbound trunks use **FRA** by default. The selected POP is part of the inbound trunk domain, which uses the format `..in.phone.systems`. For example, `abcd123456.fra.in.phone.systems` for **FRA** or `abcd123456.nyc.in.phone.systems` for **NYC**. When you change the POP and save the trunk, phone.systems(TM) updates the domain automatically. Inbound trunks created before POP selection was available use a domain without a POP, in the format `.in.phone.systems`. These trunks keep their current domain when you edit and save other settings. The domain changes to the new format only when you change the POP. Important After changing the POP, update the domain in your VoIP provider's forwarding settings. [![Domain and POP fields in the Edit Inbound Trunk window](../../_images/pop.png)](../../_images/pop.png) **Fig. 4.** Inbound trunk domain and POP --- ## Creating Inbound Trunks Use inbound trunks to define how incoming SIP traffic from your providers is received and processed by phone.systems(TM). To create a new inbound trunk: 1. Go to the **Inbound Trunks** tab under **Trunks**. 2. Click the [![+-symbol](../../_images/%2B-symbol.png)](../../_images/%2B-symbol.png) button in the lower-right corner to open the **Create Inbound Trunk** window. [![Create Inbound Trunk window](../../_images/fig529.png)](../../_images/fig529.png) **Fig. 5.** Creating an inbound trunk ### General Settings The **General** section defines the core behavior of the inbound trunk. | **Setting** | **Description** | | --- | --- | | **Friendly Name** | A descriptive name for the inbound trunk. | | **Transport Protocol** | Specifies the SIP transport method. Available options are: - **UDP** - **TCP** - **TLS** | | **POP** | The DIDWW point of presence that processes calls for the inbound trunk. Available options are: - **FRA** (default) - **NYC** The selected POP is included in the inbound trunk domain. See [Inbound Trunk POP](#ps3-inbound-trunk-pop). | | **Lookup destination by** | Determines how phone.systems(TM) identifies the destination for incoming calls. Available options are: - **R-URI username part** - Uses the **Request-URI** user portion. - **To header username part** - Uses the **To** header user portion. | | **Allowed Codecs** | Multiple codecs may be selected for call negotiation. Options include: - **OPUS** - **G722** - **PCMU** - **PCMA** - **G729** - **GSM** - **telephone-event** | Note The codec priority may be rearranged by dragging the listed codecs into the desired order. The left-most codec has the highest priority. Important To use DTMF functions such as Interactive Menu navigation or Feature Codes, ensure that **telephone-event** is included in the Allowed Codecs list. [![General settings for an inbound trunk](../../_images/general-pop.png)](../../_images/general-pop.png) **Fig. 6.** Inbound trunk general settings ### Registration Settings If your provider requires SIP registration, enable **Registration** and enter the parameters supplied by your service provider or system administrator: | **Field** | **Description** | | --- | --- | | **Domain** | The SIP registrar domain used for registration. | | **Port** | The SIP registrar port. If left empty, the SRV or A record will be used. | | **Username** | The SIP username provided by your VoIP service provider. | | **Password** | The authentication password for SIP registration. | | **Contact User** | The value that will appear in the Contact header's user part during registration. | Note Registration is disabled by default. [![Registration settings for an inbound trunk](../../_images/registration.png)](../../_images/registration.png) **Fig. 7.** Registration settings ### CLI Rules **CLI Rules** allow you to override the Source Caller Name or Destination number for calls received on the inbound trunk. This functionality enables flexible number handling and helps you identify which inbound trunk was used to receive a call. | **Field** | **Description** | | --- | --- | | **SRC number rule** | Select a predefined rule that normalizes the Source Number (CLI): - **Remove + if exist** - Removes the leading `+` if the number includes it. - **Add + if doesn't exist** - Adds a leading `+` if it is missing. | | **SRC Name Rewrite Rule** | POSIX Regular Expression pattern used to match the Source Caller Name. | | **SRC Name Rewrite Result** | Replacement text applied when the Rewrite Rule matches. | | **DST Rewrite Rule** | POSIX Regular Expression pattern used to match the destination number. | | **DST Rewrite Result** | Replacement text applied when the Rewrite Rule matches. | Note Knowledge of POSIX Regular Expressions is required to configure CLI Rules. After completing the CLI Rules configuration, click **Save** to create the inbound trunk. [![CLI Rules for an inbound trunk](../../_images/cli-rules.png)](../../_images/cli-rules.png) **Fig. 8.** CLI Rules --- ## Editing Inbound Trunks To update the configuration of an existing inbound trunk: 1. In the **Inbound Trunks** list, click the **Actions** button next to the trunk you want to modify. 2. Select **Edit** to open the **Edit Inbound Trunk** window. [![Actions Menu](../../_images/actions_menu.png)](../../_images/actions_menu.png) **Fig. 9.** Opening the Edit window for an inbound trunk 3. Adjust the settings in the **General**, **Registration**, or **CLI Rules** sections as required. 4. Click **Save** to apply your changes. Note Changing the **POP** changes the inbound trunk domain. Update the domain in your VoIP provider's forwarding settings. See [Inbound Trunk POP](#ps3-inbound-trunk-pop). [![Edit Inbound Trunk window](../../_images/edit-pop.png)](../../_images/edit-pop.png) **Fig. 10.** Editing an inbound trunk --- ## Deleting Inbound Trunks To delete an existing inbound trunk: 1. In the **Inbound Trunks** list, click the **Actions** button next to the trunk you want to remove. 2. Select **Delete** to open the **Delete Inbound Trunk** dialog. [![Actions Menu](../../_images/actions_delete.png)](../../_images/actions_delete.png) **Fig. 11.** Opening the Delete dialog for an inbound trunk 3. To permanently delete the inbound trunk and unlink its relations, enable the **Delete and unlink relations** toggle. 4. Click **Delete** to confirm. Note Deleting an inbound trunk also removes all linked relations. This may disrupt existing call routing or connected services. If you prefer not to proceed, close the dialog and update or remove the related items manually. [![Delete Inbound Trunk dialog](../../_images/delete.png)](../../_images/delete.png) **Fig. 12.** Delete Inbound Trunk dialog On this page