Configure Zoom Phone Business Plus to use Twilio SIP Trunking

This guide describes how to connect Zoom Phone to Twilio Elastic Session Initiation Protocol (SIP) Trunking. Twilio offers this guide to telecommunications engineers who install and configure the customers SIP Trunking service for Public Switched Telephone Network (PSTN) access. This guide covers Zoom's Number Management features.

Twilio's Elastic SIP Trunking connects an enterprise's SIP infrastructure to the PSTN. Trunking manages routing to and from your private exchange from and to the PSTN:

• Make outbound calls from your network to the PSTN, known as Termination.
• Receive inbound calls on Twilio phone numbers on your network, known as Origination.

The complexity of your deployment might vary and involve Interactive Voice Responses (IVRs), call centers, or multiple sites. The method remains the same: connect your SIP communications infrastructure to Twilio, and Twilio routes your outbound and inbound PSTN traffic.

The Zoom Phone Business Plus plan offers an enterprise cloud phone system including support for bring your own carrier (BYOC) options. Zoom calls these options Zoom Phone Premise Peering PSTN and Zoom Phone Carrier Peering PSTN. This lets Zoom customers choose from a range of PSTN connectivity services.

To implement BYOC, add the Zoom Phone Business Plus license to your Zoom service. This enables a SIP trunking interface in the Zoom Cloud. The interface connects directly to your designated SIP trunking service provider.

To protect the interface from external threats, both providers use virtualized session border controllers. All sessions encrypt signals with the Transport Layer Security (TLS) and media with Secure Real-time Transport Protocol (SRTP).

To connect Twilio Elastic SIP trunking with Zoom Phone, complete the following three activities.

1. Set up one or more Twilio Elastic SIP Trunks.
2. Set up an equal number of Zoom trunks.
3. Set up your Zoom Phone System.

To route calls to and from Zoom Phone, create an Elastic SIP Trunk. As Zoom Phone has presence in five geographical regions, create one trunk in each geographic location that your account permits.

1. If you logged out of Twilio Console, log back in before continuing.
2. Click Explore products in the left navigation rail.
3. Scroll to Super Network.
4. Click Elastic SIP Trunking.
5. Go to Manage > Trunks in the left navigation rail.
   The Elastic SIP Trunks page displays.

In this section, you limit access to the Twilio trunks to only the groups of IP addresses representing Zoom Phone. These groups of Zoom Phone IP addresses, known as Classless Inter-Domain Routing (CIDR) blocks, identify which network connections Twilio SIP Trunk should accept. To limit connections to allowed network addresses, you need to create an access control list (ACL). This ACL needs a name and one Zoom Phone IP address in the form of a CIDR block. After you create the ACL, add the remaining Zoom Phone IP addresses to that ACL.

1. If you logged out of Twilio Console, follow the steps in Open the Elastic SIP trunking dashboard section before continuing.

2. In the left navigation under Elastic SIP Trunking, click Manage, then IP access control lists.

3. Click + Create new Access Control List.
   The New Access Control List modal displays.
   From this modal, you create an IP-based access control list with one named IP address range. After you create this ACL, you can add more IP ranges.

4. Enter the following values into the fields for your ACL and first IP address range.

   Field	Value	Purpose
   ACL Friendly Name	Zoom ACL	Sets a human-readable label given to a list of IP ranges.
   IP Address Range Friendly Name	Singapore Zoom	Sets a human-readable label given to one range of IP addresses.
   CIDR Network Access	170.114.157.217	Sets the IP address that the SIP trunk can access.
   Range	32	Sets the range to the single IP address.

5. Click Create ACL.

   • This closes the New Access Control List modal and creates the Zoom ACL.
   • The {Friendly Name} page displays with the following values:
     • CIDR Network Access set to 170.114.157.217/32
     • IP Address Range Friendly Name set to Singapore

6. Add the remaining IP ranges one at a time:

   1. Click + Create new IP Address Range.

   2. Populate the fields with the values in the following table and set the Range to 32.

      IP Address Range Friendly Name	CIDR Network Address
      Tokyo Zoom IP address	170.114.186.224
      Melbourne Zoom IP address	159.124.65.189
      Sydney Zoom IP address	159.124.97.189
      Amsterdam Zoom IP address	159.124.9.100
      Frankfurt Zoom IP address	159.124.41.100
      San Jose Zoom IP address	144.195.113.234
      Ashburn Zoom IP address	206.247.113.234
      Mexico Zoom IP address	159.124.129.189
      Brazil Zoom IP address	64.211.144.247

   3. Click Add IP Address Range.

   4. Repeat for each location.

To learn more about Zoom's Twilio migration, consult their migration guide.

For each geographical region you want to connect with Zoom, create a new Twilio Elastic SIP Trunk.

Create a new Elastic SIP trunk and turn on secure trunking:

1. If you logged out of Twilio Console, follow the steps in Open the Elastic SIP trunking dashboard section before continuing.
2. Click Create new SIP Trunk.
   The Create A New SIP Trunk modal displays.
3. Enter a human-readable name for your trunk in the Friendly Name field.
   For the purposes of this guide, enter Asia Pacific Zoom Trunk in the Friendly Name field.
   Subsequent repetitions of this step would use Australian Zoom Trunk, European Zoom Trunk, North American Zoom Trunk, South American Zoom Trunk.
4. Click Create.
   The General Settings page displays for your new trunk. Ignore any settings on this page for the purposes of this guide.
5. Toggle Secure Trunking to enabled. Leave the other settings as given.
6. Click Save in the bottom navigation bar.
   A banner displays You have successfully updated your Trunk. at the top of this page.
7. To return to the Trunks page, click the left arrow on the left side of your new Trunk's name in the left navigation rail.
8. Repeat steps 2 to 7 for each Zoom region.

Configure how your trunk sends outgoing traffic through the PSTN to the call recipient. This process, also known as PSTN Termination, provides URIs through which Zoom Phone can route calls.

1. If you logged out of Twilio Console, follow the steps in Open the Elastic SIP trunking dashboard section before continuing.

2. Click the link with your trunk name.
   The General Settings page displays.

3. Click Termination in the left navigation rail.
   The Termination page displays.

4. Click Show Localized URIs.
   A list of URIs for Twilio's various Edge Regions around the world appears.

5. Type a unique hostname for your SIP trunk in the Termination SIP URI field.
   The list of localized URIs updated with your SIP trunk hostname prepended to their domain.

   (information)

   Example of a regional SIP URI

   If you type mypbx into the Termination SIP URI field, the North America Virginia localized SIP URI displays mypbx.pstn.ashburn.twilio.com.

   If you use the default SIP URI, traffic to your PBX routes to {SIP_HOSTNAME}.pstn.ashburn.twilio.com.

6. Select the table of localized URIs and copy it.

7. Paste this table into a temporary text file that you create in your preferred text editor. You need to share this data with Zoom operations.

8. Scroll to the Authentication section of the Termination page.

9. From the IP Access Controls Lists dropdown menu, select the ACL you created in the Create network-based access control list rules section.

10. Click Save in the bottom navigation bar.

Configure how your trunk routes incoming traffic from a caller to the PSTN. This process, also known as PSTN Origination, sets URIs through which Zoom Phone routes calls through the Twilio SIP trunks.

Create a set of URIs that receive calls from Zoom Phone:

1. If you logged out of Twilio Console, follow the steps in Open the Elastic SIP trunking dashboard section before continuing.
2. Click one of the regional trunks that you created in the Create the Twilio SIP trunk task.
3. Click Origination in the left navigation rail. The Origination page displays.
4. Add four Origination URIs. Each URI represents a combination of the Zoom Phone origin and the Twilio trunk.
   For each of the four Origination URIs, perform the following steps.

   1. Click + under Origination URIs. The Add Origination URL modal displays.

   2. Click on the following recommended Origination URIs table that relates to your trunk's region.

   3. Copy the first URI in the Origination URI column.

   4. Paste it into the Origination SIP URI field.

   5. Set the Priority field value to 1. Increase this value by 1 with each repetition of this step.
      This field accepts positive integers from 0 to 65535 and defaults to 10. A lower value represents higher importance. A URI with a Priority value of 1 should receive traffic with greater frequency that one with a Priority value of 10.

   6. Leave the Weight field value at 10.
      This field accepts positive integers from 1 to 65535 and defaults to 10. A higher value represents a higher share of traffic. A URI with a Weight value of 50 receives a greater amount of traffic than one with a Weight value of 10.

   7. Leave the Enabled toggle set to Enabled.

   8. Click Add. This closes the Add Origination URL modal.

   9. If successful, a green banner displays that states Origination url added.

   10. Repeat these steps three more times, using the second, third, and fourth entries in the tables.

5. Toggle CNAM Lookup to On.
6. Click Save in the bottom navigation bar. This preserves the Origination settings.
7. If successful, a green banner displays that states Trunk updated.

If you had set up Twilio Elastic SIP Trunks to work with Zoom Phone before, these Zoom IP addresses have changed. To reflect these new Zoom IP addresses, edit any existing Origination URIs.

Add the Phone Numbers from a given country that you want to associate with each relevant Trunk.

The Zoom operations team configures the connection to Twilio Trunks. This team requires the following two lists of data:

1. The list of regional trunks with their associated localized termination URIs.
   You created these regional trunks earlier in this guide.

   Location	Localized Termination URI
   North American Trunk	{customerdefined}.namer.pstn.ashburn.twilio.com {customerdefined}.namer.pstn.umatilla.twilio.com
   European Trunk	{customerdefined}.emea.pstn.dublin.twilio.com {customerdefined}.emea.pstn.frankfurt.twilio.com
   South American Trunk	{customerdefined}.latam.pstn.sao-paulo.twilio.com
   Asia Pacific Trunk	{customerdefined}.apac.pstn.singapore.twilio.com {customerdefined}.apac.pstn.tokyo.twilio.com
   Australian Trunk	{customerdefined}.aus.pstn.sydney.twilio.com

2. The list of Twilio CIDR blocks that the Elastic SIP Trunking services use.

Zoom Phone Premises Peering, or BYOC-P, enables you to use Twilio's Elastic SIP Trunking for PSTN access. To have the Zoom trunks configured with Twilio, work with your Zoom account team. Be sure to provide them with the information you collected in the previous section.

This section provides guidelines for key areas to look at when configuring your Zoom Phone system. To receive detailed instructions, contact your Zoom account team.

Zoom allows peering in the following regions.

At this time, you can only view your Premise Peering SIP trunks. To review your SIP trunks, perform the following steps.

1. Log in to your Zoom web portal as an administrator.
2. Using the left navigation rail, scroll to the Admin section.
   If the Admin section doesn't display, you lack the necessary privileges for Zoom administration.
3. Go to Phone System Management > Company Info > Account Settings > SIP Trunk.
   The SIP Trunk page displays. This page includes following read-only data for each trunk:
   • trunk name
   • trunk carrier type
   • region
   • Zoom Session Border Controller (SBC) trunk label To use Twilio SIP trunking, one trunk requires a carrier type of BYOC.

If you need additional connections, contact your Zoom account team through Zoom support.

To configure your call routing information, follow these steps.

1. Log in to your Zoom web portal as an administrator.

2. Using the left navigation rail, scroll to the Admin section.
   If the Admin section doesn't display, you lack the necessary privileges for Zoom administration.

3. Go to Phone System Management > Company Info > Account Settings > Routing.
   The Routing page displays.

4. Review and edit your SIP Groups as needed. For each group, you can configure the following settings:

   • Set the Name of the SIP Group
   • Assign one or more pre-defined Trunk Groups to the SIP Group
   • Add a human-readable explanation of this SIP Group's purpose as a Description
   • Apply policies for location-based routing
   • Import external contacts

   Zoom Phone routes any outgoing calls from the SIP Groups to the assigned Trunk Groups.

5. Review and edit your Route Groups as needed. For each group, you can configure the following settings:

   • Set the Name of the Route Group
   • Assign one or more pre-defined Trunk Groups for BYOC to the Route Group
   • Importing external contacts for a Global Directory
   • Applying the policy of location-based routing

1. Log in to your Zoom web portal as an administrator.
2. Using the left navigation rail, scroll to the Admin section.
   If the Admin section doesn't display, you lack the necessary privileges for Zoom administration.
3. Go to Number Management > Phone Numbers.
   The Phone Numbers page displays.
4. Watch Zoom's guide on how to add phone numbers. This video shows a different page flow to the Phone Numbers page, but otherwise follows the same workflow.

How Zoom Phone handles outbound calls depends on the user's Calling Package. A user can place a call to the PSTN using Native Zoom Phone, Premise Peering PSTN (BYOC) or both.

Calling packages require configured phone numbers. These numbers can include native numbers created in the Zoom web portal or numbers created in another carrier like Twilio .

If you need multiple SIP trunks to establish the desired outbound routing, Zoom operations coordinates this option with you.

Successful configuration of your Zoom Phone system results in the following outcomes:

• Calls your users make go to your Twilio Elastic SIP Trunk and routed to the PSTN
• Calls received on your Twilio phone numbers route first to Zoom Phone then to the right extension or user.

To learn more, consult the Elastic SIP Trunking user documentation.