SDN and beyond

Software-defined networking (SDN) and network function virtualization (NFV) are new approaches to designing and operating mobile networks, granting operators better management possibilities and better use of the network capabilities.

NFV represents the virtualization of network nodes roles, which culminates in separate software implementations performing the functions typically executed by hardware components. At the other end, SDN uses the virtualisation technology to split the control plane (where you need flexibility) from the data plane (where you need speed/performance). However, the price for this is complexity which translates into high operation costs.

Operators benefit from such frameworks because they increase the network capacity and performance, and allow for better manageability.

The YateUCN approach recognizes the usefulness of separating the user plane and the data plane, but it implements both of them in software. The control plane is implemented in the user space for flexibility while the user plane in the kernel space for speed.

As a result, operators who deploy YateUCN networks will gain from considerably scaling down equipment, and will have better control over the network scalability and performance requirements. The image below shows the YateUCN implementation and a common SDN deployment using an OpenFlow switch.

Unified Core Network vs. Common SDN deployment

Common NFV/SDN implementations rely on virtualizing the EPC, so that the functions of the MME (Mobility Management Entity), the SGW (Serving Gateway), and the PGW (Packet Data Network Gateway) are each implemented in software and run on the same hardware. Drawbacks of this approach include:

  • the separation between the control and user plane is achieved by means of a switch, usually hardware-based and external to the network. This is a limitation of software-defined network functions;
  • the switch is designed to replace the PGW and obtain the IP connection which it sends to the eNodeB over the user plane. This means that it must support both GTP protocol for the user plane and IP which determines the high costs for such equipment.
  • the complexity of NFV requires additional effort from the network to accommodate it, which increases the overall cost of the solution.

The implementation of YateUCN differs significantly from the above.

First, it uses commodity hardware, so no special-purpose equipment needs is needed. Simply put, YateUCN is a COTS server, which completely diminishes investment, staff, space, and power requirements.

Secondly, YateUCN differs from virtualized EPC because it implements a unique software, based on Yate, that performs all functions of the MME, SGW, and PGW. All-software implementation also means that multiple protocols (Diameter, SS7) are equally implemented in YateUCN, and no additional implementations are required for the core to connect to the Home Subscriber Server or IMS. This helps operators cut down on highly specialized staff needs and facilitates inter-working with legacy networks.

Thirdly, instead of using a hardware switch, YateUCN implements it in the Yate kernel. Because the Unified Core Network is based on Yate, an expandable Linux-based telephony engine, it was possible to integrate a software switch in the core software, allowing for much faster data processing and eliminating the need to work with multiple vendors.

YateUCN core network solution removes the barriers of entering the market due to simplicity, scalability and low cost. YateUCN specifications features and specifications list can be accessed here.

2 thoughts on “SDN and beyond

  1. Pingback: YateUCN, the cloud EPC | Yate - Software Defined Mobile Networks

  2. Pingback: YateUCN, the EPC cloud | Yate - Software Defined Mobile Networks

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