g very light per-packet processing An order of magnitude less than what the hardware could do (more than 10 Gbps per core, 40+ Gbps per x86 server) Bottlenecks TCP stack and Linux kernel in NFV virtual machines Hypervisor virtual switch NIC TCP offload works only with VLANs Solutions Optimized virtual switches (ex: INTEL DPDK) Dedicated virtual NICs (hypervisor bypass) Figure 5. Performance Indicators of NFV LINUX LINUX os and Networking Stack Network Application Bottlenecks Driver level Server Platform Bottleneck Virtual Machine Bottleneck Application Application Application Software Software Software Communication Bottleneck Hypervisor Virtual Switch vSwitch Bottleneck Server Platform Driver level Bottleneck Downloaded: 4/15/2022 9:44:49 AM lova Southeastern University IP Address: 137.52.76.29 Virtualizing Network Functions in Software-Defined Networks Dedicated packet processing CPU cores User-mode packet processing (viz. PF_RING) VIRTUALIZATION OF NETWORK SERVICES Various Ways to Achieve Virtualization of Network Services The virtualization of network services can be achieved through a number of ways; however, they all use the same form of architecture what is defined in Network Attached Storage (NAS) or shared form of other storage/memory architecture. One of the most popular methods of virtualization of network services includes the use of Linux virtual containers. Moreover, other methods include: A- Separate portioned hypervisor B- Use of multiple/compartmentalized operating systems C- Use of bare metal machines D- Embedded hypervisor E- Composite, distributed or clustered services/functions F- Shared storage Figure 6. Methods of Network Services Virtualization Shared State Linux Linux Linux Linux Linux Linux os + Hypervisor OS1+HV os 1 + Hypervisor Downloaded 4/15/2022 9:44:49 AM Nova Southeastern University IP Address: 137.52.76.29 Virtualizing Network Functions in Software-Defined Networks Virtualizing Network Functions in Blade Server and Virtualization Environments Some of the major features of using 