PBX Configuration Guide

Overview

This article provides guidance for enterprise administrators on configuring the PBX Connector to ensure a successful connection to the underlying PBX instance.

The instructions outlined here are part of a collaborative process between you—the Enterprise Admin—and the Service Provider. For a complete overview of the setup workflow, refer to PBX Connector Installation Step-by-Step Guide. The process also includes a step for creating Direct Routing.

Once Direct Routing is established, the next step is to add one or more PBX systems that will be linked to Microsoft Teams users. You must configure at least one PBX, which is the focus of this article.

Watch Video
The instructions for this process are also available in video form in ConnecttoTeams- Provisioning.

Adding a PBX

To add a PBX, do the following:

Log in to the Service Portal.
From Enterprise Admin Menu, click on the PBX menu item.
The Configured PBXs page will appear.
Click the Add PBX button.
The PBX Settings page will appear.
Enter the values for the following fields:

PBX Type: This is the manufacturer of the PBX. This field is a drop-down menu that lists the PBX types provided to the enterprise by the service provider.
PBX Credential Template: If the selected PBX type is one of these platform (Netsapiens, RingLogix, United Cloud, Viirtue), the enterprise admin may use a template prepared by Service Provider which stores API credentials needed for Netsapiens Integration. Moreover, you will have to configure the "Advanced Settings" tab. Carry out the steps to configure the Advanced Settings after doing the last step mentioned in this article.
PBX Location: A PBX Location is a single instance of the PBX type. Enter your preferred name for this PBX instance. For deployments involving multiple PBXs, assigning a clear and descriptive location-based name helps distinguish each instance.
PBX DNS Lookup type: The options are Host and SRV. If you select SRV you will NOT be prompted to select a PBX SIP Domain Proxy Port. If you are using SRV here is a more detailed article about using DNS-SRV with the ConnecttoTeams Connector.
PBX Outbound Transport Type: UDP, TCP, TLS or UDP/TCP. Most PBXs use UDP.
More info
The UDP/TCP option allows SIP traffic to use UDP when possible, but it will use TCP when necessary due to packet size. We will attempt to use UDP for SIP signaling when we are initiating a flow and the initial INVITE is less than 1300 bytes. In some call situations, this limit is exceeded and UDP traffic would likely fragment and lead to failed calls. In these cases, we will attempt to use TCP.

Note: If you are using Host lookup, your PBX must support both UDP and TCP on the same endpoint and port. If you are using SRV lookup then you must have both _udp and _tcp DNS records configured correctly.
PBX SIP Domain: The domain you enter here needs to follow the RFC-3261 rules. For Users set up on this PBX their SIP Users will be created with this domain (i.e. [email protected]). The SIP domain must be a valid host, which is either an IP-address or a hostname. The BNF for the hostname is reproduced here.
```
hostname    = *( domainlabel "." ) toplabel ["." ] 
domainlabel = alphanum / alphanum *( alphanum / "-" ) alphanum
toplabel    = ALPHA / ALPHA *( alphanum / "-" ) alphanum 
```
Note: This means that toplabel -- the final domain component, or the only domain component if there are no "dots" in the domain" -- MUST start with a letter.
PBX SIP Domain Proxy: If you are utilizing a Session Border Controller or a SIP Proxy in front of your PBX, input the Public IP address here. This is an optional field, if nothing is entered all SIP messages will be sent to the PBX SIP Domain.
Voicemail Feature Code: This controls the feature code sent to the PBX to invoke check voicemail. There is a default for each PBX in ConnecttoTeams that can be adjusted to the actual Feature Code used by a specific PBX.
PBX SIP Domain Proxy Port: Most PBXs use a standard port - 5060. If your PBX uses a different port, change the input to the correct Port.
Codecs: Click each codec you wish to enable, in the order you wish them to be attempted. For full list of supported codes, check Supported Codecs article. There must be at least one codec enabled or the system will revert to a default of G.711 A-law.
Mark the Enforce Codecs on Inbound checkbox to force inbound calls to use the codecs specified on the above Codecs field.
Topology Hiding: This is intended to strip out internal network legs from the SIP headers so as to avoid exposing internal network topology and to reduce the number of headers such as Via and Record-Route.
Reg Expires: This is the value we include in our REGISTER request. This value in seconds suggests an expiration time. However, the registrar (customer PBX) decides the actual expiration time in their 200 OK response, which might differ from our request. The default value is 600.
Delay ACK Relay?: Delays relaying the ACK to the remote target until the remote endpoint generates it, instead of sending it right after receiving the 200Ok.
Caller Name Policy: This setting controls the name transmitted to upstream systems for outbound calls. For more information, see CallerID and PAI Settings for PBX and Trunk.
Caller ID on Forwarded Calls: Controls the called ID sent to the PBX when a call is forwarded. For more information, see CallerID and PAI Settings for PBX and Trunk.
Pause Inbound Calling based on Teams Presence: Disables inbound calls to Teams when the Teams user status is not Available. The "Pause Inbound Calling Based on Teams Presence" feature prevents incoming calls from ever reaching the voicemail of unavailable Teams users.
Method: Method for rejecting inbound calls. Options are: SIP 480, NS As-Feature-Event, BS As-Feature-Event. For more info about these options, see Pause Inbound Calling Based on User Availability on MS Teams article.

Interval in Minutes: If SIP 480 method is chosen, this is the time interval the call is blocked after a presence unavailability event.
Encoded Feature Codes supported?:
When this option is enabled for the PBX, the feature codes defined on the PBX App Soft Keys page should be encoded when dialed out.
Escape Request URI?:
Certain characters have special meanings in URIs and SIP headers. For example:
: separates the scheme from the rest of the URI.
@ separates the user info from the host.
If these characters are part of the actual data, they need to be escaped to avoid being misinterpreted as delimiters or control characters. Enabling this option will accomplish this.
Convert History Info to Diversion?
Microsoft Teams utilizes the SIP History-Info header to convey information related to the sequence of a call. This is useful in call transfer and forwarding scenarios. Some upstream systems do not support the History-Info header and instead utilize the SIP Diversion header for this purpose. When this option is enabled, the ConnecttoTeams B2BUA will convert the History-Info header to the Diversion header.
Enable MWI Events?
If your PBX supports subscription to Message Waiting events as defined in RFC 3842 this option will cause the the system to make the necessary subscriptions. Note that MWI subscription is necessary to show an event card when a new voicemail message arrives.
If the Advance Settings tab is present, enter the values for the fields in this tab.

- If the PBX Type is Broadworks, follow the steps discussed in the next section.

- If the PBX Type is one of these — Netsapiens, RingLogix, United Cloud, Viirtue — follow the detailed steps presented in Configure Connector for Netsapiens PBX.
Click the Save Settings button when all settings have been configured.

Result: After saving PBX settings a Success Completed card displays in the right-hand corner.

Additional Configurations for BroadWorks PBX

The "Advanced Settings" tab will be available if your selected PBX Type is a Broadworks platform. Proceed to fill out the following fields in Advanced Settings tab. See the How to Provision PBX Settings and Add User for BroadWorks for more information.

Optional PBX Settings

The PBX tab lists the PBXs you have created for the enterprise.

To the right of each PBX Location there is an Action Menu that provides you the following options:

Edit allows you to change the PBX Settings as shown in Add PBX above.
Manage/Add/Bulk Add Feature Codes takes you to the Feature Code pages.
Add Feature Codes will provide a guide to set up, management and capabilities of feature codes.

Once you have added one or more PBXes with the sub-settings you need, continue on adding users, either individually or in bulk.

Common PBX Troubleshooting Steps

I added Users and they still have a red indicator in the PBX Registration	The PBX info is incorrect or you need to white list /v' IP address. Please confirm that the PBX is seeing the attempted registration and reporting on the failure.	Triple check PBX SIP credentials for the user you are installing. If you need to whitelist ConnecttoTeams IP address here is the info.
Conference calls are being managed by Microsoft instead of the PBX	This is the default Teams setting.	Switch the settings in Teams Admin to Don’t Allow Dialouts
I selected the wrong PBX type and now I can’t change it.	Unfortunate. However, you can build a new PBX using the correct type.	Once you build a PBX of the correct type, and rebuild your users there, you should be able to delete the old PBX with the wrong type if there are no users tied to it.
An indicator is red and I need to turn it green	Many indicators; many causes.	See Turning Red Indicators Green for the full guide for all indicators throughout the portals.
Calls are failing, either for the whole enterprise or a particular user	There are multiple possible root causes, some related to PBX Settings.	See Calls are Failing: Troubleshooting Steps for more details.