Ribbon SBCs Enable Webex Calling & Cisco CUCM Migrations

Webex Local Gateway makes it easy for organizations to choose their own telecom provider for Webex Calling. Ribbon Session Border Controllers (SBCs) are deployed locally or in the cloud to provide a voice firewall between an organization’s network, their preferred telecom provider and Webex Calling. Ribbon SBCs provide robust security services and simplify interoperability, leveraging two decades of real-world experience deploying tens of thousands of SBC devices/instances across the globe.

Ribbon SBCs act as a local gateway in the Cisco Webex architecture. Ribbon SBCs provide telecom access for Webex Calling and can also connect Webex Calling to existing on-premises phone systems/PBXs such as a Cisco CUCM. This allows customers to keep existing on-premises call control while they transition to Webex Calling. If needed, the on-premises call control can remain in permanent use, co-existing with Webex Calling. It’s ideal for Cisco customers that are adopting Cisco’s Flex licensing.

Ribbon SBCs can be deployed as traditional hardware, as virtualized software, or in the public cloud, including AWS, Azure or GCP.

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SBCs that Squarely Outperform the Competition

Ribbon SBCs are a Better Choice

Many Cisco customers are familiar with their existing choices for SBC solutions. Ribbon SBCs offer more capabilities and better value for Local Gateway deployments.

Ribbon advantages

1.  Ribbon SBCs offer greater scale

  • Branch offices  (under 100 concurrent calls)
  • Regional offices (1000 and under concurrent calls)
  • HQ (up to 150,000 concurrent calls)

2.  Flexible deployment models:

  • Hardware appliances (with multiple legacy interface options)
  • Multiple virtual environments (multiple hypervisors)
  • Private & public cloud (Azure, AWS, and GCP)

3. Broad interoperability for deployment in heterogeneous environments

  • Assures investment protection for future communication choice

4. Proven carrier-grade security and performance

5. The same solution also protects premises or cloud contact centers

Download the Config Guides

Get Connected to Webex Calling

Ribbon SBCs Make it Easy to Move 1 or 10,000 Users

  1. Acquire a Webex Calling license or Cisco Collaboration Flex Plan license.

  2. Pick a telecom provider (use existing or new). The telecom provider’s SIP trunks will be delivered to a Ribbon SBC deployed in the organization’s office, data center, or in the cloud. A special Webex-certified provider is not required – the Ribbon SBC assures interoperability.

  3. Ribbon’s Session Border Controller will terminate the SIP trunks and pass the calls to the Webex Cloud or a local PBX (such as a Cisco CUCM) or both.

  4. The SBC acts as a secure voice firewall, mitigates SIP interoperability issues, and manages media connectivity. Most of Ribbon’s SBCs are Webex Local Gateway certified (see chart below).

What is the SBC’s Role in Webex Local Gateway?

Webex requires a Webex-certified SBC to act as a bridge between the Webex Cloud, a premises phone system (such as a Cisco CUCM), and an organization’s telecom provider. The session border controller provides multiple functions:

  • Security – it acts as a voice-aware firewall, protecting the voice traffic itself and it prevents bad actors from entering the data network via the voice network.

  • Interoperability – Ribbon’s SBCs can adjust key deployment parameters to best match the telecom provider’s requirements, the Webex Cloud’s requirements, and a premises phone system's requirements.  All the pieces connect and work!

  • Legacy Connectivity – many organizations still have analog, BRI, or PRI-based trunk ports, analog phones, elevator phones, door phones, and fax machines. Ribbon’s hardware-based SBCs have analog & digital ports (FXS and FXO) to keep these assets connected and available.

  • CUCM Migration – organizations may have technical or business requirements that require the Cisco CUCM (or other PBXs) to stay connected for an extended period. Ribbon SBCs can provide SIP forking and simultaneous ringing so that both Cisco Webex and the legacy PBX share connectivity.

  • Resiliency or Failover – Ribbon SBCs have multiple options to manage disruptions in service depending on the deployment model. These tools can keep your organization connected even if the unexpected happens.



Webex Local Gateway Deployment Model with a Ribbon SBC  


SBC Options for Every Size Environment

Superior Security and Performance


RIbbon SBC SBC 1000 SBC 2000 SBC SWe Edge SBC 5400 SBC 7000 SBC SWe

Session Count (concurrent calls)






Server    Dependent

Webex Certified

March 2023

March 2023

March 2023

T1/E1/ or BRI Ports (connects legacy PBXs)

Up to 2 T1/E1
or 12 BRI ports

Up to 16 T1/E1 – 2 x 8 T1/E1 spans

Analog/TDM gateway required

Analog/TDM gateway required

Analog/TDM gateway required

Analog/TDM gateway required

FXS Ports (analog phones, fax, etc.)

Up to 24 FXS ports

Up to 48 FXS ports
– 2 x 24 ports

Analog/TDM gateway required

Analog/TDM gateway required

Analog/TDM gateway required

Analog/TDM gateway required

FXO Ports (analog lines for emergency calling, etc.)

Up to 12 FXS ports

Analog/TDM gateway required

Analog/TDM gateway required

Analog/TDM gateway required

Analog/TDM gateway required

Analog/TDM gateway required


More on SBC 1000

More on SBC 2000

More on SBC SWe Edge

More on SBC 5400

More on SBC 7000

More on SBC SWe

Protect Your Network from Communication Threats

Certificate-based Authentication Offers Better Performance

Ribbon SBCs deployed as Webex Local Gateways rely on modern Certificate-based Authentication (CBA) rather than more traditional SIP registrations. CBA uses a digital certificate, acquired via cryptography, to identify the user (or device), granting access to a network or communications application. This security model:

  • Eliminates fixed devices with generic passwords
  • Digital certificates are installed centrally, enables end-to-end encryption
  • Eliminates end user engagement (or lack thereof)
  • Covers all endpoints types 
  • Mutual authentication

Using Certificate-based Authentication also eliminates potential SIP registration storms, making Ribbon solutions a better choice for larger, multi-site deployments.

Proven Professional Services Organization

Ribbon has decades of experience building session border controllers for the world’s largest carriers. That’s why Ribbon understands the importance of reliability and efficiency. Our software and hardware are designed to be operational 24/7, even during upgrades. Ribbon SBCs have undergone rigorous 3rd party testing to prove they can withstand withering attacks while continuing to protect the network.

It’s no surprise that the largest financial institutions, governments, utilities, healthcare organizations, universities and more, trust Ribbon. We’ve helped organizations of all sizes, in more than 140 countries, move to the cloud. We can help you too.