The concept of NFV is simple. it tends to convert the functions that exist in your “physical network” to a virtual. functions like DPI, BNG and route reflectors will be converted to Virtual machines.
The left hand side of the picture is called “MANO = Management and Orchestration” where the right hand side of the standard is the real hardware and bunch of hypervisors (KVM, ESXI)
This allow to create many use cases such as service chaining on which subscriber traffic could be easily passed by any type of VNFs (Virtual Network Functions) regardless of it’s physical location. For example the below subscriber traffic is passed by virtual firewall, DDoS and virtual DPI before sending it out to the internet. Other subscriber traffic could be passed by a different “chains”
Cisco has a wide portfolio that cover most of the ETSI components, Let’s explore them in brief
NFV-O : Orchestrator
Cisco has the NSO product (Network Service Orchestrator, before it’s called Tail-F NCS). Tail-F has a huge contribution in defining the YANG language used in service modeling in the NFV. Cisco acquire the Tail-F company two years ago and it’s one of the most successful acquisition in cisco. You can read more about the Tail-F in thislink. The orchestrator job is to orchestrate the service creation over the VNFs and push the correct configuration on them based on many triggers
NSO use a concept of NEDs (Network Element Drivers) that capable of communicate with many many vendors like Sandvine, Palo-alto, Juniper and of course Cisco. it also capable of communicate using the NetConf protocol that allow it to not only orchestrate the VNF but also the PNF (Physical Network Functions – The real hardware and ASICs).
VNF-M: VNF Manager
because your network functions will be a bunch of VMs (Firewall, DPI,..etc). You will need to have a “manager” that manage the CRUD(Creation, Redeploy, Update and Deletion) operation of those VMs. Cisco has a product that called ESC (Elastic Service Controller) that integrate very well with NSO and any type of orchestrator in northbound. In southbound it ‘s capable to communicate with Openstack and VMware through standard RESful services.
The virtual infrastructure manager (openstack or vcenter) are responsible of creating the actual HDD, RAM and CPU for the VNF. Cisco recommend to integrate with RedHat Openstack (RDO)
EMS (or VNF)
This is the network function that become virtual! . I used in this lab the Cisco Cloud Service Router (CSRv) that capable on running most of the ASR functions without a problem (side note: I used it to build a complete SP-WiFi lab for one of the operator here in Egypt and it work very well in EAP-SIM and Portal based scenarios). below is the available VNFs from cisco
My NFV Lab
First I tried to integrate the Cisco Elastic Service controller with Vmware vCenter but not having much luck on this integration. I stucked in starting the orchestrator service in vCenter process on which I’m thinking it’s one of the component that used by cisco ESC for communicating with VMware infrastructure. also vCenter seems complex solution to me on which limiting my options
Although the ESC is connected to vCenter, and able to read all “tenants” or VMs from it, but it was unable to administrate them
Hmmm, Ok. let’s seal to the other destination, The Openstack
Second I imported the ESC to the openstack and installed it using the bootvm.py python script.
Great. next step is to integrate the ESC with Openstack that took only two minutes! (Thank you VMware for wasting my time!!)
Third, Once Integration is done, You can see that ESC can successfully retrieve all the tenants from the openstack
Also it’s capable of communicating with Openstack services like nova, cinder
And finally it’s capable of reading all compute hosts and hosted instances
Fourth, Push the configuration from orchestrator to ESC and watch Openstack create the images, flavors and attach all networks to CSRv (through the ESC)
if you check the ESC portal, you will see immediately the CSR VNF Active, up and running in the ESC
And you can access the CSRv console directly from the ESC through the built-in VNC utility
But really, what’s the job of the ESC?
ESC play a vital role as a VNF manager in monitoring the VNF operations. for example if one of the VNF that created through the ESC is deleted by mistake. the ESC will detect this event and immediately re-deploy the impacted machine without any intervention from your side. You can program it with many events to be monitored like overloading the VM, underloading, License experience..etc
The ESC communicate with openstack through REST messages over HTTP and order it to create VM (VNF) with specific flavor, Image ID and attached networks) as shown in blow snoop between ESC and Openstack
NFV is one of the hottest topics in service provider area and it soonest they will convert to this model to save much power and space in datacenter and more important is to introduce agility and harmony in today’s complex network. I really recommend you to choose open standard solutions and not limit your options to propriety software. Learn openstack and YANG modeling and be open minded to automation mythology
Finally I’ve the complete NFV lab integrated components (Orchestrator, VNF-Manager, Openstack and VNF) up and running in my company lab. I think it’s the first lab of it’s type here in Egypt to the best of my knowledge
for any questions, please post a comment and we can discuss it together