For our client, a global organization, desk conferencing was becoming one of the main means of effective communication. However, the costs of providing remote connectivity using standard PSTN was spiraling and in some cases, connectivity was proving to be a major issue. To address these issues our client tasked us with providing a solution that not only addressed these issues but also provided a highly available, secure, and easy to use communication medium that could be adopted into standard practice.
Requirements – Business Drivers
- Reduction of operational costs including PSTN Toll charges
- Simplistic access to conference system
- High level of reliability
- Scalable solution
Challenges:
- High interlock of solution with core networking technologies
- Globally diverse network, non-availability of Dial in and Dial back numbers in 77 countries in which customer is having presence
- Complex RACI
What our Consultant did:
- Conducted requirement gathering with client and reviewed the requirements.
- Investigated the client’s global data and voice networks for reliability and capacity
- Verified current license capacity and future scaling requirements, current user dialing habits
Solution
Implementation of WebEx Cloud Connected Audio (CCA)
- CCA provides very attractive audio pricing against PSTN
- Built on existing IP Telephony infrastructure to create intuitive WebEx conference experience
- Introduction of Globally available Call-In and Call-back numbers
Solution Implementation
CCA will be implemented along with Routing, Switching, Security, Unified Communications, and WebEx to provide a rich media conferencing and collaboration platform. Solution generally will be deployed in two data centers to provide access and redundancy in the environment. Each location will have a carrier Ethernet circuit providing connectivity between the location and a Service Provider backbone network. The overall solution will have Edge routers, Cisco Unified Border Elements, DSP farms and Switches all combined to provide a highly flexible, scalable, and resilient network.
Solution Diagram

Solution Details:
- Service Provider Network: SP send calls in G711, if customer uses G.729 for internal calls, then transcoding is needed. BGP peering to Cisco network and customer network
- Cisco Unified Border Element: 3x ISR 4451 per site. Same skeleton configuration in all 6 Cubes. CUBE also hosts PVDM DSP modules for transcoding. BGP protocol run between CUBE and SP network
- Cisco Unified Communications Manager (CUCM) and IP phones: SIP trunks are built between CUCM and CUBE, media flows directly between IP phones and CUBE
- ASA Firewall: 1 Firewall per datacenter, required ports are open to allow SIP and media traffic
WebEx User Dialing Patterns

While users join WebEx calls, they dial from IP-phone to join conference. For Call-back scenario users can dial their extension in WebEx interface. Both these calls will be routed via above SP network and customer build CCA solution.
End Result
Successful implementation of CCA solution that met all the requirements of the client that resulted in greater adoption of conference type communication in the workplace enhancing working practices.
Benefits
- Massive cost savings
- 30 % (1.7m $) reduction in PSTN charges in 1st year
- 50 % (2.8m $) in 2nd
- Simplistic and intuitive conference system that was adopted as main form of business communication
- Enhance working practices resulting in numerous operational improvements