This is a copy of a previous Linkedin Post Dated June 7 2016 which was not present on this Blog.
In telecom networks the option to place an LTE vEPC stands out as an exemplary demonstration of NFV’s application. The figure below gives the generic NFV Architecture. It be divided into 3 main sections:
- The Management and Orchestration
- Consists of NFV Orchestrator, VNF Manager and Virtualization Infrastructure Manager.
- The NFVI – NFV Infrastructure
- Consists of Hardware, Virtualization Layer and Compute, Storage, Network Virtualization Software
- The VNFs – i.e. the virtual network functions.
The type of function the VNF provides shows what this NFV network delivers. That is if the NFV network delivers as a Network Service an LTE Core end to end communication then there will be EPC functionality implemented and provided by the VNF part of the NFV network.
See the figure below from an ETSI Proof of Concept work.
It shows the vendor CYAN providing NFV Orchestrator (NFVO) and VNF Manager (VNFM). Redhat and Openstack provide the Virtualized Infrastructure Manager (VIM). The figure also shows the relevant Infrastructure hardware and hypervisor software solutions. Finally it shows the VNFs as being Connectem’s vEPC. If the VNF was implementing a different functionality say it was a vIMS then the rest of the components in the figure could be the same and the end to end Network Service being provided by the NFV network would be different. Therefore the function implemented inside the VNF defines what service the NFV network provides. Therefore the work done by the VNF decides whether your NFV network is Telco or Enterprise; LTE or WiMAX; LTE or 3G etc.
For a list of possible Telco VNF’s see the figure below.
Every chuck of functional blocks could be implemented together as a VNF. So what Connectem is doing is implementing the LTE MME, SGW, PGW, HSS, PCRF functionality and packaging it as a VNF which can be run atop virtualized infrastructure. In the ETSI Proof of Concept, Connectems solution therefore does this according the NFV specifications so that the VNF can be managed by a VNFM and its infrastructure is composed so as it can be managed by a VIM and all this can be controlled and coordinated by an NFVO i.e. NFV Orchestrator. Therefore you get an LTE EPC functionality inside the virtualized NFV environment.
The ETSI definition of a VNF is that a VNF is “a Network Function capable of running on NFV Infrastructure (NFVI) and being orchestrated by a NFV Orchestrator (NFVO) and VNF Manager”.
Coming back to our vEPC example the VNF has components. These VNF Components (VNFCs) can logically be pictured as below:
ETSI mandates that a vendor can choose to implement components as they wish inside the VNF environment as long as they speak to the other NFV architecture components as per their defined VNF interfaces. This means that the different components can utilize efficient compute storage and networking procedures instead of the standards body defined communication methodology. An example is that inside the vEPC software the MME will communicate with the SGW but will utilize efficient computational methodology instead of the 3GPP defined interfaces. If for some reason (say a lab environment) a vendor chooses to implement the 3GPP interfaces inside their vEPC it won’t be as fast and as efficient but it can be used to showcase 3GPP communications inside NFV.
Good VNFCs software design is what will distinguish different providers of vEPC software solutions.