Clearwater Core IMS

A cloud native IMS core for cost-effective, scalable and resilient VoLTE and beyond

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    The only 100% cloud native IMS core implementation

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    Delivers highly scalable I/S-CSCF, BGCF and CCF

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    Telco-grade reliability in IT-grade cloud infrastructures

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    Supports both hypervisor and container environments

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    Works with independent VNF managers and MANO

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    Automated instantiation and lifecycle management


Clearwater Core is Metaswitch’s implementation of IMS built exclusively using web development methods to provide voice, video and messaging services to millions of users or IoT endpoints. Architected from the ground up for massively scalable deployments within virtualized public, private or hybrid elastic compute clouds, Clearwater Core combines the economics of over-the-top (OTT) style service platforms with the standards compliance and reliability expected of telco-grade network solutions.

The web services-oriented design, along with the component-centric micro services philosophies adopted when architecting Clearwater Core, makes it ideal for instantiation within either hardware VM-based hypervisor infrastructures (VMware or KVM) or emerging OS container-based (Docker) environments with (Swarm or Kubernetes) Cluster management.

  • Cloud native VNFs
  • Includes I-CSCF, S-CSCF and BGCF
  • Charging Collection Function (CCF) converts Rf-based billing streams into file-based CDRs
  • HSS Mirror eliminates unnecessary queries of the global user database
  • Works with VNF managers and management and orchestration (MANO) options
  • Uses RESTful web services APIs
  • Compatible with Metaswitch’s Perimeta SBC and AGCF/MGCF
  • Compatible with Metaswitch’s Service Assurance Server for monitoring, statistics and analytics

Download our white paper "The application of cloud native design principles to network functions virtualization".

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Why use Metaswitch’s Clearwater Core IMS?

The IP Multimedia Subsystem (IMS) is finally ready to deliver on the promise of ubiquitous VoLTE and converged rich communications services; but to fully realize the potential, network operators must think beyond simple virtualized network functions to fully cloud native IMS components.

When designing Clearwater Core, Metaswitch adapted web design principles to fit the requirements of SIP and IMS so that Clearwater Core could deliver dynamic, granular, elastic scalability and unmatched resilience even in IT-grade cloud infrastructures.

  • Our cloud native software is robust, scalable and flexible
  • Avoids the high overheads and costly redundancy of virtual machines running in a hypervisor environment
  • Automated instantiation and lifecycle management can save time and resources
  • Components scale individually using our unique stateless load-balancing techniques
  • Traffic loads are spread evenly as nodes are added and removed from each layer
Metaswitch's innovative, web-scale software solutions have allowed us to dramatically reduce our capital expenditures and operating costs by moving subscribers away from proprietary equipment to Metaswitch's high-performance software running on industry standard hardware, in our 'telco cloud'.


Kevin Paige
CTO, Manx Telecom

Contact us to request a consultation about Clearwater IMS Core

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