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..10).
20 - Number of NFs per service instance (e.g. 1,2,4..10).
22 The initial implementation of NFV service density tests in
23 |csit-release| is using two NF applications:
25 - VNF: DPDK L3fwd running in KVM VM, configured with /8 IPv4 prefix
26 routing. L3fwd got chosen as a lightweight fast IPv4 VNF application,
27 and follows CSIT approach of using DPDK sample applications in VMs for
29 - CNF: VPP running in Docker Container, configured with /24 IPv4 prefix
30 routing. VPP got chosen as a fast IPv4 NF application that supports
31 required memif interface (L3fwd does not). This is similar to all
32 other Container tests in CSIT that use VPP.
34 Tests are designed such that in all tested cases VPP vswitch is the most
35 stressed application, as for each flow vswitch is processing each packet
36 multiple times, whereas VNFs and CNFs process each packets only once. To
37 that end, all VNFs and CNFs are allocated enough resources to not become
40 Service Configurations
41 ~~~~~~~~~~~~~~~~~~~~~~
43 Following NFV network topologies and configurations are tested:
45 - VNF Service Chains (VSC) with L2 vswitch
47 - *Network Topology*: Sets of VNFs dual-homed to VPP vswitch over
48 virtio-vhost links. Each set belongs to separate service instance.
49 - *Network Configuration*: VPP L2 bridge-domain contexts form logical
50 service chains of VNF sets and connect each chain to physical
53 - CNF Service Chains (CSC) with L2 vswitch
55 - *Network Topology*: Sets of CNFs dual-homed to VPP vswitch over
56 memif links. Each set belongs to separate service instance.
57 - *Network Configuration*: VPP L2 bridge-domain contexts form logical
58 service chains of CNF sets and connect each chain to physical
61 - CNF Service Pipelines (CSP) with L2 vswitch
63 - *Network Topology*: Sets of CNFs connected into pipelines over a
64 series of memif links, with edge CNFs single-homed to VPP vswitch
65 over memif links. Each set belongs to separate service instance.
66 - *Network Configuration*: VPP L2 bridge-domain contexts connect each
67 CNF pipeline to physical interfaces.
69 Thread-to-Core Mapping
70 ~~~~~~~~~~~~~~~~~~~~~~
72 CSIT defines specific ratios for mapping software threads of vswitch and
73 VNFs/CNFs to physical cores, with separate ratios defined for main
74 control threads and data-plane threads.
76 In |csit-release| NFV service density tests run on Intel Xeon testbeds
77 with Intel Hyper-Threading enabled, so each physical core is associated
78 with a pair of sibling logical cores corresponding to the hyper-threads.
80 |csit-release| executes tests with the following software thread to
81 physical core mapping ratios:
85 - Data-plane on single core
87 - (data:core) = (1:1) => 2dt1c - 2 Data-plane Threads on 1 Core.
88 - (main:core) = (1:1) => 1mt1c - 1 Main Thread on 1 Core.
90 - Data-plane on two cores
92 - (data:core) = (1:2) => 4dt2c - 4 Data-plane Threads on 2 Cores.
93 - (main:core) = (1:1) => 1mt1c - 1 Main Thread on 1 Core.
97 - Data-plane on single core
99 - (data:core) = (1:1) => 2dt1c - 2 Data-plane Threads on 1 Core per
101 - (main:core) = (2:1) => 2mt1c - 2 Main Threads on 1 Core, 1 Thread
102 per NF, core shared between two NFs.
104 Maximum tested service densities are limited by a number of physical
105 cores per NUMA. |csit-release| allocates cores within NUMA0. Support for
106 multi NUMA tests is to be added in future release.