Ribbon EdgeMarc SBC Configuration with Zoom BYOC

Document Overview

This document outlines the configuration best practices for the Ribbon EdgeMarc SBC when deployed with Zoom BYOC (Bring Your Own Carrier).

A ​Session Border Controller​ (​SBC​) is a network element deployed to protect​ ​SIP​ based Voice over Internet Protocol​ (VoIP) networks. ​Early deployments of SBCs were focused on the borders between two service provider networks in a peering environment. This role has now expanded to include significant deployments between a service provider's access network and a backbone network to provide service to residential and/or enterprise customers. ​The interoperability compliance testing focuses on verifying inbound and outbound calls flows between Ribbbon EdgeMarc and Zoom cloud. The Ribbon EdgeMarc SBC is deployed on the customer site to resolve any potential numbering format issues between Zoom and the customer's existing carrier dial plan numbering. 

This guide contains the following sections: 

• Section A: EdgeMarc Configuration
  
  • Captures general EdgeMarc configurations for deploying with Zoom BYOC.
    

• Section B: Zoom Web BYOC configuration

  • Captures the Zoom BYOC configuration.

  • All basic calls, along with the supplementary features like call hold, call transfer, and conference can be tested with configurations from Section A and Section B.
    

  • Advanced supplementary features can be configured on Zoom as mentioned in Supplementary Services Configuration on Zoom. These cover:

    • Auto Receptionist

    • Call Flip

    • Shared Line Appearance (SLA) or Call Delegation

    • Shared Line Group (SLG)
      

• Section C: TLS/SRTP Configuration Between Ribbon EdgeMarc and Zoom
  • Captures the TLS/SRTP configuration between EdgeMarc and Zoom cloud.
  • If transport is TLS and media is SRTP, follow the steps in this section, followed by B2BUA for routing, E.164 numbering, and header manipulations in Section A.
    

Non-Goals

It is not the goal of this guide to provide detailed configurations that will meet the requirements of every customer. Use this guide as a starting point and build the SBC configurations in consultation with network design and deployment engineers. 

Audience

This is a technical document intended for telecommunications engineers with the purpose of configuring both the Ribbon SBCs and the third-party product. Steps will require navigating the third-party product as well as the Ribbon SBC Command Line Interface (CLI). Understanding the basic concepts of TCP/UDP, IP/Routing, and SIP/RTP is needed to complete the configuration and any necessary troubleshooting.

Product and Device Details

The sample configuration in this document uses the following equipment and software:

Network Topology Diagram

The following topology diagram shows connectivity between Zoom and Ribbon EdgeMarc 2900A.

Zoom EdgeMarc network topology diagram

Section A: EdgeMarc Configuration

The following EdgeMarc configurations are included in this section:

1. Connectivity
2. Network
3. Static Routes
4. VoIP
5. B2BUA

Connectivity

EdgeMarc Back Panel

EdgeMarc 2900a interface/port details are listed in the table:

EgeMarc 2900a Interfaces

IP-PBX (PSTN side) is connected towards the LAN interface of EdgeMarc 2900a.

Zoom cloud is connected towards the WAN interface of EdgeMarc 2900a.

EdgeMarc Network Deployment

Network

Login to the EdgeMarc as root user and click Network to configure the LAN and WAN interfaces.

EdgeMarc Network WAN Interface and DNS configuration

Static Routes

Static routes are used to create communication to remote networks. In a production environment, static routes are mainly configured for routing from a specific network to a network that can only be accessed through one point or one interface (single path access or default route).

Static routes need to be added towards LAN interface 172.16.X.X(IP-PBX) and WAN interface 162.12.X.0(Zoom), as Zoom uses multiple IP's in this subnet.

172.16.X.X is the IP of the phone behind the IP-PBX. Add the static route for the media to also work.

• Navigate to Network > Static Routes to configure the routes.

VoIP

Navigate to VoIP and check whether the LAN and WAN interfaces configured earlier are reflected accordingly.

VoIP

B2BUA Options

SIP Settings

1. Navigate to VoIP > SIP to configure the SIP settings.
2. Configure the SIP server address as the Zoom SIP server IP (for example, 162.12.X.X in our case).
3. Keep the B2BUA, UDP, and TCP settings at the default configuration.

SIP

 

B2BUA Options

UDP TCP default settings

SDP - default settings

B2BUA

1. Navigate to VoIP > SIP  > B2BUA 
2. Configure the IP address of the IP-PBX (for example, 172.16X.X in our case).

B2BUA

E.164 Country code Mapping

Example: A customer has an existing carrier that only accepts U.S.A. domestic 10 digit dial plan numbering format. For example: (XXX) YYY-ZZZZ, where XXX=area code, YYY-ZZZZ=7-digit phone number. At the same time, Zoom is using the E.164 numbering format: +(country code)(phone number). This has created a phone number format incompatibility issue between Zoom and the customer carrier. Zoom expects to receive calls in E.164 numbering format, while the customer carrier expects the USA 10-digit domestic numbering format. EdgeMarc SBC is introduced to solve the numbering interop issue between the two entities. The EdgeMarc SBC inserts a “+1” for all U.S. phone numbers destined for Zoom, and removes “+1” for all U.S. phone numbers destined for customer carrier(s). 

The following rule is required to "Add +1" to outgoing call towards Zoom.

1. Name the Rule as "AddPlusOne".
2. Check all headers and set the Country Code to "Canada/USA".

AddPlusOne

The following rule is required to "Remove +1" to call towards IP-PBX.

1. Name the Rule as "MinusPlusOne".
2. Check all headers and set the Country Code to "Canada/USA".

MinusPlusOne

Actions - ToZoomCloud

Actions - ToOrigPBX

Match - Outbound

Match - Inbound

Section B: Zoom Web BYOC Configuration

Prerequisites:

• Zoom Go BYOC account: A special type of Zoom account that has outbound/inbound SIP trunk that peers between the Zoom Phone Cloud and the customer’s PSTN carrier connection.
• Customer's existing carrier/carrier equipment: any carrier offering PSTN services. Carrier equipment can be router/gateway or another SBC that supports SIP trunk connectivity. IP-PBX was used to simulate customer carrier router/gw. Carrier has provided several DID’s to use as external BYOC numbers.
• Trunk Registration:  BYOC is a “static” trunk between 2 static IP endpoints, therefore no trunk registration is done here.

Once the Zoom Go account is available, login to Zoom Web BYOC portal at https://go.zoom.us/.

The following Zoom BYOC configurations are included in this section:

1. Add External Number.
2. Create Zoom Users.
3. Supplementary services configuration on Zoom.

Add External Number

Navigate to Phone Systems Management > Phone Numbers > External

Select Add to ​add external phone numbers provided by your carrier into Zoom portal. These numbers are the DID numbers provided by your carrier.

Add External Number

External

Add External Number

External Number created successfully

Create Zoom Users

Zoom Users are created in order to login to Zoom clients on a desktop or mobile. Create a user as follows:

1. Navigate to User Management > Users. Click Add to create new Zoom users.
2. Navigate to Phone System Management > Users & Rooms. Check for the User status "Active".
3. Navigate to Assign Calling Plan > Assign BYOC Calling Plan. Click on "Confirm and Assign Numbers".

Create Zoom User

Assign BYOC calling plan

     4. Assign the External Numbers created previously in the Add External Number section.

Choose from Unassigned Numbers

    5. Click Confirm to finish. Once the User is assigned with a Calling Plan and Number, it should look like the following example.

Configured User

Supplementary Services Configuration on Zoom

Zoom supports multiple supplementary services. To configure different supplementary services in Zoom, refer to the following links:

      1. Auto Receptionist: https://support.zoom.us/hc/en-us/articles/360001297663-Getting-started-with-Zoom-Phone-admin-#h_a625f531-94c6-4291-909e-3d68ad685b68

      2. Call Flip: https://support.zoom.us/hc/en-us/articles/360034613311-Using-Call-Flip

      3. Shared Line Appearance (SLA) or Call Delegation: https://support.zoom.us/hc/en-us/articles/360032881731

      4. Shared Line Group/SLG: https://support.zoom.us/hc/en-us/articles/360038850792/

Section C: TLS/SRTP Configuration between Ribbon EdgeMarc and Zoom

Prerequisites:

• As the TLS needs to performed on the WAN side, a trusted CA (Certificate Authority) is needed. In this scenario, GoDaddy is used as a Trusted CA.
• Zoom BYOC trunk should be enabled with TLS/SRTP.

Generate a CSR from EdgeMarc SBC

1. Navigate to Security > Certificates.
   

   Create CSR on EdgeMarc

   

2. Fill in the details as specified below:

   1. Common name: should be the valid fqdn, here "trials.com" is given as a sample configuration.

   2. Email: Provide the valid Email ID.
      

      Certificates

      
      
      

3. Download the CSR certificate from SBC and get it signed from a Trusted CA.
   

   Download CSR

   

4. Obtain the Root certificate and EdgeMarc SBC signed certificate from the Trusted CA and upload as follows:
   Key file and Password is not required.
   

   Upload Root certificate

   

5. Upload the Signed certificate from CA as follows:

   1. Certificate Name: SBCpem (in our case).

   2. Certificate Type: SSL.

   3. Select certificate file: Signed SBC certificate from Trusted CA.

   4. Select Key file: Private key of SBC.
      

      Upload the Signed certificate from CA

      
      
      

6. Navigate to VoIP > SIP.

   1. Apply the following settings as mentioned below.
      

      SIP Settings

      

7. Choose the SBCpem certificate that was uploaded in a previous step.
   

   TLS cipher and WAN certificate

   

8. SRTP calls need the following configuration:

   1. Navigate to VoIP > Media Security.
      

      SRTP config