As more organizations adopt Cisco Webex Calling, one of the most important design decisions IT leaders face is how to connect the platform to the Public Switched Telephone Network (PSTN).
PSTN connectivity is what enables Webex users to make and receive external calls. Without it, Webex Calling would be an internal-only system.
Cisco provides three main options for PSTN connectivity: Cisco Calling Plans, Cloud Connected PSTN (CCP), and Local Gateway (LGW).
Each approach has different implications for cost, flexibility, features, and scalability.
This article explains these options in detail, compares them side by side, and shows why many enterprises and MSPs choose the Local Gateway approach.
What Is Webex Calling PSTN Connectivity?
Even in a cloud-first world, PSTN connectivity remains essential. It’s what links cloud phone systems like Webex Calling to the wider telephone network, allowing users to dial external numbers, receive inbound calls, and maintain compatibility with legacy systems.
Without PSTN connectivity, Webex Calling would only support internal calls between Webex users.
For IT leaders, deciding on the right PSTN model isn’t just a technical choice, it directly impacts cost, resilience, and the ability to scale globally. For Cisco’s own documentation on Webex Calling connectivity, see: https://help.webex.com/en-us/article/n1qbbp7/Features-Available-by-License-Type-for-Webex-Calling
Cisco Webex Calling Plans (PSTN via Cisco Calling Plans)
Cisco Calling Plans are Cisco’s simplest PSTN option. In this model, Cisco acts as the carrier, providing phone numbers, call minutes, and routing services. Licenses are purchased on a per-user, per-month basis, with PSTN breakout bundled directly into the subscription.
This makes Calling Plans fast to deploy and straightforward to manage, but they come with important limitations.
Pros
- One vendor for both Webex platform and PSTN connectivity
- Predictable per-user pricing
- Fully hosted and managed by Cisco
Cons
- Regional availability is limited
- No ability to bring your own carrier (BYOC)
- Minimal control over number management or routing
- Not designed for hybrid or legacy PBX integration
Best Fit: SMBs or single-region organizations that need a quick, predictable solution with minimal IT overhead.
If you’d like a deeper look at how Cisco Webex Calling Plans are structured, what they cost, and how they compare to other phone system models, see our dedicated guide: Cisco Webex Calling Plans & Pricing Explained.
Cisco Webex Calling Cloud Connected PSTN (CCP)
Cloud Connected PSTN (CCP) gives organizations the ability to select from Cisco-certified PSTN providers. These providers connect directly to Webex Calling through Cisco’s cloud infrastructure, offering global reach and enterprise-grade reliability.
However, customers are still restricted to Cisco’s approved carrier list, and custom routing or hybrid use cases may be limited.
Pros
- 100% cloud-based – no on-premises hardware needed
- Access to Cisco-certified global carrier partners
- High reliability backed by Cisco certification
Cons
- Choice limited to Cisco’s certified carrier list
- Less control over routing policies
- Integration with legacy PBXs or generic SIP endpoints is not native
Best Fit: Mid-market and enterprise organizations that want a cloud-first PSTN model but can work within Cisco’s certified partner ecosystem.
Local Gateway for Webex Calling PSTN
The Local Gateway (LGW) model provides the highest level of flexibility and control. A Local Gateway acts as a bridge between Webex Calling and the PSTN, and can be deployed on-premises or virtually in the cloud.
With LGW, organizations can bring their own carrier (BYOC), retain existing SIP trunks, integrate existing legacy telephony such as PBXs. This makes it the preferred option for enterprises that require the most flexibility to build and operate hybrid deployments.
Advantages
- Full control over PSTN connectivity – BYOC (connect any carrier) or PSTN
- Seamless hybrid integration with PBXs, SIP phones, Microsoft Teams, and legacy systems by leveraging services like Callroute who use LGW as the basis of Webex PSTN connectivity
- Advanced routing policies and number management
- Removes the need to port numbers or exit existing carrier contracts
Best Fit: Enterprises that require the ultimate carrier choice and may have complex telephony environments.
For Cisco’s Local Gateway documentation, see: https://help.webex.com/en-us/article/8jgdo3/Local-Gateway-Overview
Comparing Webex Calling PSTN Options
The table below compares Cisco Calling Plans, Cloud Connected PSTN, and Local Gateway across cost, features, flexibility, and enterprise fit.
| Criteria | Cisco Calling Plans | Cloud Connected PSTN (CCP) | Local Gateway (LGW) |
| Cost | Predictable per-user | Moderate, provider-based | Variable (BYOC/Callroute) |
| Features & Integration | Core PBX features (voicemail, transfer, call forwarding, hunt groups, Webex app integration) | Strong cloud integration, but limited to Cisco-approved providers | Full feature set, hybrid integration with PBX, Teams, SIP devices |
| Flexibility | Low – fixed bundles | Medium – some provider choice | High – BYOC, full routing control |
| Carrier Choice | Cisco only | Cisco-certified carriers | Any carrier (BYOC) |
| Resilience | Limited, dependent on Cisco cloud | High cloud reliability, but no local survivability | Full survivability with local breakout + failover |
| Best Fit | SMBs, single-region orgs | Mid-market, cloud-first orgs | Enterprises, hybrid, MSPs needing control |
This comparison shows how Calling Plans provide simplicity and predictability, while CCP expands reach through Cisco partners, and Local Gateway offers the greatest flexibility, resilience, and control, particularly valuable for enterprises with complex telephony environments.
Why Callroute Is the Best Webex Calling PSTN Provider
At Callroute, we’ve built our Webex Calling integration around the Local Gateway model because it offers customers the perfect balance between cloud simplicity and flexibility to integrate with other voice environments (e.g. PBXs, Microsoft Teams etc).
With Callroute, you can:
- Connect any carrier, or use Callroute PSTN powered by BT and Gamma
- Provision numbers in minutes through our intuitive web platform
- Integrate seamlessly with Microsoft Teams or existing PBXs
Key Takeaways for IT Leaders
Choosing the right PSTN model is about more than connectivity. It impacts cost, flexibility, and long-term scalability.
- Cisco Calling Plans are the simplest entry point but limited in scalability and carrier flexibility
- Cloud Connected PSTN offers global reach but locks you into Cisco-approved carriers
- Local Gateway provides the most control, hybrid integration, and long-term value
For IT leaders, the right PSTN model depends on scale, geography, and integration requirements.
But for enterprises, MSPs, and organizations planning for long-term growth, Local Gateway with Callroute delivers the flexibility, resilience, and transparency that modern communications demand.
To see how Callroute Webex Calling works and to discuss if it is the right option for your business, book a demo with our team.
