4 Network Function Virtualization (NFV) service density tests focus on
5 measuring total per server throughput at varied NFV service “packing”
6 densities with vswitch providing host dataplane. The goal is to compare
7 and contrast performance of a shared vswitch for different network
8 topologies and virtualization technologies, and their impact on vswitch
9 performance and efficiency in a range of NFV service configurations.
11 Each NFV service instance consists of a set of Network Functions (NFs),
12 running in VMs (VNFs) or in Containers (CNFs), that are connected into a
13 virtual network topology using VPP vswitch running in Linux user-mode.
14 Multiple service instances share the vswitch that in turn provides per
15 service chain forwarding context(s). In order to provide a most complete
16 picture, each network topology and service configuration is tested in
17 different service density setups by varying two parameters:
19 - Number of service instances (e.g. 1, 2, 4, 6, 8, 10).
20 - Number of NFs per service instance (e.g. 1, 2, 4, 6, 8, 10).
22 Implementation of NFV service density tests in |csit-release| is using two NF
25 - VNF: VPP of the same version as vswitch running in KVM VM, configured with /8
27 - CNF: VPP of the same version as vswitch running in Docker Container,
28 configured with /8 IPv4 prefix routing.
30 Tests are designed such that in all tested cases VPP vswitch is the most
31 stressed application, as for each flow vswitch is processing each packet
32 multiple times, whereas VNFs and CNFs process each packets only once. To
33 that end, all VNFs and CNFs are allocated enough resources to not become
36 Service Configurations
37 ~~~~~~~~~~~~~~~~~~~~~~
39 Following NFV network topologies and configurations are tested:
41 - VNF Service Chains (VSC) with L2 vswitch
43 - *Network Topology*: Sets of VNFs dual-homed to VPP vswitch over
44 virtio-vhost links. Each set belongs to separate service instance.
45 - *Network Configuration*: VPP L2 bridge-domain contexts form logical
46 service chains of VNF sets and connect each chain to physical
49 - CNF Service Chains (CSC) with L2 vswitch
51 - *Network Topology*: Sets of CNFs dual-homed to VPP vswitch over
52 memif links. Each set belongs to separate service instance.
53 - *Network Configuration*: VPP L2 bridge-domain contexts form logical
54 service chains of CNF sets and connect each chain to physical
57 - CNF Service Pipelines (CSP) with L2 vswitch
59 - *Network Topology*: Sets of CNFs connected into pipelines over a
60 series of memif links, with edge CNFs single-homed to VPP vswitch
61 over memif links. Each set belongs to separate service instance.
62 - *Network Configuration*: VPP L2 bridge-domain contexts connect each
63 CNF pipeline to physical interfaces.
65 Thread-to-Core Mapping
66 ~~~~~~~~~~~~~~~~~~~~~~
68 CSIT defines specific ratios for mapping software threads of vswitch and
69 VNFs/CNFs to physical cores, with separate ratios defined for main
70 control threads and data-plane threads.
72 In |csit-release| NFV service density tests run on Intel Xeon testbeds
73 with Intel Hyper-Threading enabled, so each physical core is associated
74 with a pair of sibling logical cores corresponding to the hyper-threads.
76 |csit-release| executes tests with the following software thread to
77 physical core mapping ratios:
81 - Data-plane on single core
83 - (main:core) = (1:1) => 1mt1c - 1 main thread on 1 core.
84 - (data:core) = (1:1) => 2dt1c - 2 Data-plane Threads on 1 Core.
86 - Data-plane on two cores
88 - (main:core) = (1:1) => 1mt1c - 1 Main Thread on 1 Core.
89 - (data:core) = (1:2) => 4dt2c - 4 Data-plane Threads on 2 Cores.
93 - Data-plane on single core
95 - (main:core) = (2:1) => 2mt1c - 2 Main Threads on 1 Core, 1 Thread
96 per NF, core shared between two NFs.
97 - (data:core) = (1:1) => 2dt1c - 2 Data-plane Threads on 1 Core per
100 - Data-plane on single logical core (Two NFs per physical core)
102 - (main:core) = (2:1) => 2mt1c - 2 Main Threads on 1 Core, 1 Thread
103 per NF, core shared between two NFs.
104 - (data:core) = (2:1) => 2dt1c - 2 Data-plane Threads on 1 Core, 1
105 Thread per NF, core shared between two NFs.
107 Maximum tested service densities are limited by a number of physical
108 cores per NUMA. |csit-release| allocates cores within NUMA0. Support for
109 multi NUMA tests is to be added in future release.