Cisco Webex Calling, a cloud-based telephone system.

Cisco Webex Calling, a cloud-based telephone system.

Cisco Webex Calling

Webex Calling, a cloud-based telephone system.

For companies that have been waiting for a trusted brand to offer a multi-user cloud-based alternative available globally to their local PBX, the wait is over.

Cisco Webex® Calling offers all the features of a traditional PBX through a subscription service.

Main features Cisco Webex Calling:

  • An advanced set of business-level PBX features.
  • An enriched user experience that includes the Cisco® Webex Calling application for mobile and desktop users, integrated with the Cisco Webex Teams ™ collaboration application.
  • Support for an integrated user experience with Cisco Webex Meetings and Webex devices, including 6800, 7800 and 8800 series desk phones from Cisco IP phones and analog ATAs.
  • Delivery from a set of geo-redundant data centers distributed regionally throughout the world.
  • Service available in a growing list of countries in each region.
  • Protection of existing investment in any local Cisco Unified Communications Manager (UCM) license, through the flexible Cisco collaboration plan.
  • A smooth migration to the cloud at your own pace, through cloud and mixed cloud support and local implementations.


PSTN connectivity

How is PSTN connectivity provided with Webex Calling ?

Webex Calling allows you to locally connect your existing PSTN service to the Webex cloud through the use of Cisco-approved gateways.

What hardware, gateway, is compatible to connect Cisco Webex calls to the PSTN ?

Webex Calling allows your client to connect your existing PSTN service to the Webex cloud through Cisco gateways. The following Cisco Unified Border Element (CUBE) devices are compatible with Webex Calling to connect your client’s PSTN service:

Cisco 4321, 4331, 4351, 4431, and 4451 Cisco Integrated Services Routers (ISR) that use version 16.9 of the Cisco IOS® XE software (3)

Cisco Cloud Services Router 1000 Series (CSR 1000V) with virtual CUBE and Cisco IOS XE Software version 16.9 (3)

Cisco 1100 ISR with Cisco IOS XE software version 16.11

Note: CUBE call licenses are included in the Cisco Webex Calling Flex Plan license. CUBE selection requirements are governed by the needs of encryption and decryption. (The signaling and means to Cisco Webex Calling are always safe)


An example gateway and software that should be used:

For Webex calls with less than 200 users, you can use the Cisco 4321 Integrated Services Router (ISR) with the required Cisco IOS® XE software.

The 4321 ISR will support up to 40 sessions, therefore 200 users in a 1: 5 ratio. If you need more sessions, a more powerful router will be required. Here is an example bill of materials (BOM) for an ISR 4321:

4321 ISR hardware ISR4321/K9


Unified communication license for Cisco 4320 ISR SL-4320-UC-K9


Security license for cisco 4320 ISR SL-4320-SEC-K9


For environments with more than 200 users, we recommend an ISR 4331 and the required CUBE software. The 4331 ISR will manage up to 200 sessions. With a 5: 1 ratio, it can provide support for up to 1000 users. This will vary according to the client.

Are calls encrypted?

Yes, call traffic is encrypted end to end.

Can you use a gateway that supports the Webex Calling on-premise and cloud solution to support users?

Yes. One of the advantages of using a gateway to provide PSTN connectivity to cloud users is that it is an important first step in helping the client transition to the cloud at the pace that best suits their business strategy.

What are the benefits for the end customer of Webex Calling?

Customers can:
  • Transform your business by migrating to collaboration and communication solutions in the cloud.
  • Reduce the cost and complexity of technology and provide a more agile and intuitive way of working.
  • Integrate innovative and reliable brand in cloud collaboration, security and solution delivery.
  • Integrate with Cisco Webex Meetings and Teams to provide an exceptional cognitive collaboration experience.
  • Migrate at your own pace and protect existing investments with the hybrid cloud options of the Flex Plan.
  • Improve global and multi-site customer service, as well as remote and mobile worker connectivity.

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