docs: vpp stateless traffic generator

Add a use-case writeup.

Type: docs

Signed-off-by: Dave Barach <dave@barachs.net>
Change-Id: Ib6e79e80455edbdeedcc96943dd98f16c57c559e
(cherry picked from commit b8f6122b4f4c828dee103d1f3116d27e6e3e6f3a)
This commit is contained in:
Dave Barach
2021-01-20 12:20:13 -05:00
committed by Dave Wallace
parent ddb39ff0fd
commit 9479838d08
2 changed files with 106 additions and 0 deletions

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@ -20,3 +20,4 @@ extensive list, but should give a sampling of the many features contained in FD.
networksim
webapp
container_test
trafficgen

105
docs/usecases/trafficgen.md Normal file
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Vpp Stateless Traffic Generation
================================
It's simple to configure vpp as a high-performance stateless traffic
generator. A couple of vpp worker threads running on an older system
can easily generate 20 MPPS' worth of traffic.
In the configurations shown below, we connect a vpp traffic generator
and a vpp UUT using two 40 gigabit ethernet ports on each system:
```
+-------------------+ +-------------------+
| traffic generator | | UUT |
| port 0 | <=======> | port 0 |
| 192.168.40.2/24 | | 192.168.40.1/24 |
+-------------------+ +-------------------+
+-------------------+ +-------------------+
| traffic generator | | UUT |
| port 1 | <=======> | port 1 |
| 192.168.41.2/24 | | 192.168.41.1/24 |
+-------------------+ +-------------------+
```
Traffic Generator Setup Script
------------------------------
```
set int ip address FortyGigabitEthernet2/0/0 192.168.40.2/24
set int ip address FortyGigabitEthernet2/0/1 192.168.41.2/24
set int state FortyGigabitEthernet2/0/0 up
set int state FortyGigabitEthernet2/0/1 up
comment { send traffic to the VPP UUT }
packet-generator new {
name worker0
worker 0
limit 0
rate 1.2e7
size 128-128
tx-interface FortyGigabitEthernet2/0/0
node FortyGigabitEthernet2/0/0-output
data { IP4: 1.2.40 -> 3cfd.fed0.b6c8
UDP: 192.168.40.10 -> 192.168.50.10
UDP: 1234 -> 2345
incrementing 114
}
}
packet-generator new {
name worker1
worker 1
limit 0
rate 1.2e7
size 128-128
tx-interface FortyGigabitEthernet2/0/1
node FortyGigabitEthernet2/0/1-output
data { IP4: 1.2.4 -> 3cfd.fed0.b6c9
UDP: 192.168.41.10 -> 192.168.51.10
UDP: 1234 -> 2345
incrementing 114
}
}
comment { delete return traffic on sight }
ip route add 192.168.50.0/24 via drop
ip route add 192.168.51.0/24 via drop
```
Note 1: the destination MAC addresses shown in the configuration (e.g.
3cfd.fed0.b6c8 and 3cfd.fed0.b6c9) **must** match the vpp UUT port MAC
addresses.
Note 2: this script assumes that /etc/vpp/startup.conf and/or the
command-line in use specifies (at least) two worker threads. Uncomment
"workers 2" in the cpu configuration section of /etc/vpp/startup.conf:
```
## Specify a number of workers to be created
## Workers are pinned to N consecutive CPU cores while skipping "skip-cores" CPU core(s)
## and main thread's CPU core
workers 2
```
Any plausible packet generator script - including one which replays
pcap captures - can be used.
UUT Setup Script
----------------
The vpp UUT uses a couple of static routes to forward traffic back to
the traffic generator:
```
set int ip address FortyGigabitEthernet2/0/0 192.168.40.1/24
set int ip address FortyGigabitEthernet2/0/1 192.168.41.1/24
set int state FortyGigabitEthernet2/0/0 up
set int state FortyGigabitEthernet2/0/1 up
ip route add 192.168.50.10/32 via 192.168.41.2
ip route add 192.168.51.10/32 via 192.168.40.2
```