Introduction

Inject latency into all matching egress traffic.

Prerequisites

If you are not using our container images for the extension, you need install the tc (from the iproute2 package) tool to use the attack.

Details

The network delay operates at the ip level and affects single packets (network layer, level 3). Thus, it works for UDP and TCP traffic, and you may encounter HTTP requests that are delayed by a multiple of the specified delay.

In this example the traffic is delayed by 500ms. If you tap the wire (using tcpdump) and feed it into Wireshark it looks like shown in the image above.

1. The first incoming packet initiates the tcp connection and is accepted by the second packet, which is delayed exactly be the 500ms.

2. With the fourth packet we receive an HTTP request in the payload. Which is acknowledged and answered with an HTTP response in packet four to seven, which are also delayed by 500ms and thus the total latency for the HTTP request sums up to 1 second.

Parameters

Parameter	Description	Default
Duration	How long should the traffic be delayed?	30s
Hostname	Restrict to which hosts the traffic is delayed
IP Address	Restrict to which IP address the traffic is delayed
Network Delay	How much should the traffic be delayed?	500ms
Network Interface	Target Network Interface which should be attacked. All if none specified.
Port Number	Restrict to which port number the traffic is delayed
Jitter	Random +-30% jitter to network delay	true
TCP Data Packets Only	beta Delay only TCP data packets (PSH flag heuristic). UDP is not delayed. When you observe the actual delay being a multiple of the configured delay, you might choose this option to avoid delaying the TCP handshake.	false