Design of an Emulator to Control the Packet Loss and Delays for Remote Applications

Project Title

Design of an Emulator to Control the Packet Loss and Delays for Remote Applications

Project Area of Specialization RoboticsProject Summary  

Today, a large amount of data is transferred over long distances due to an increased number of real-time   applications such as live streaming, online gaming, etc. and advanced applications such as Haptics and Smart Grid, making it highly important for the developers to eliminate any characteristics in the applications that indicate poor performance and may prevent them from gaining popularity and achieving success. The performance of an application is altered by various factors when it is run on a real-world network and this may become troublesome and chaotic for the end-users so there is need for an emulation tool that can mimic the behaviour of a real network allowing developers and manufacturers to gauge their applications’ response prior to its production, development and implementation. Hence, in our project, a hardware-based network emulator that runs on Linux operating system will be designed, by considering network impairments such as packet loss, variable time delay and jitter. Furthermore, an efficient approach of controlling and stabilizing data transmission will be proposed. This emulator will enable significant improvement in production and testing of products and services thus making it a valuable tool to control data transmission for remote applications such as Haptics and Smart Grid.

Project Objectives

By using a network emulator to test an application in a given network, we can achieve the following objectives.

1. Manipulate bandwidth constraints required to run the application in the WAN.
2. Control data transmission by applying impairments such as packet loss, jitters, congestion and delay.
3. Specify latency to emulate the transfer of data over large distances.
4. Stabilize variable time delays.
5. Corrupt certain fields in the IP header or payload to check if application can overcome it without getting stuck or crashing.

Project Implementation Method

Our first step in designing the network emulator was to decide the network parameters that it will manipulate. We selected Bandwidth, Packet Loss, Time Delay and Jitter. The network emulator will be designed on Linux operating system (version 2.6.19). Its basic architecture has been decided by taking inspiration from WANEm. It comprises of a Linux Kernel, a Shell and a User Interface or GUI. in linux kernel we will use 

• HTB (Hierarchical Token Bucket): it is used for varying bandwidth
• Netem: it is a network emulator present inside some Linux versions as an open source.
• Conntrack: it enables to track connections of TCP/IP.
• Netfilter: it helps in filtering packets.

shell:  It is an interpreter and interface in which user enters commands that are then executed by the kernel.  We will use the following commands in our network emulator:

• tc: it is a shell command used to invoke HTB.
• Ip tables: it uses the netfilter function

user interface: will be designed by using open source version of GUI of Netem.

Benefits of the Project

A network emulator serves as a cross-road between live-testing and simulation. The most significant features of a network emulator include:

1. With the help of a network emulator, the need of a live network can be eliminated which is considered to be a challenging task.
2. It can be used for fast and repetitive testing.
3. It gives a better analysis and understanding of the response and performance of an application across different networking environments.
4. In case of a testing failure, it can be re-run with a simple keystroke.
5. Validation tests can be executed continuously during the development life of the application thereby increasing defect detection and resolution time.
6. It can be used in Smart Grids where verifying, examining and assessing new ideas and technologies require modelling and emulating of both communication network and power network, as well as the interactions between them.
7. Network emulator also find its uses in military where it is extremely important to analyze and validate new services and applications before deploying them in actual network to determine possible unexpected system behaviors.

Technical Details of Final Deliverable

The emulator is expected to have the following features.

1. Filtering - It can separate the traffic coming on one side of the port into different groups to represent different networks. In this way, multiple scenarios can be emulated between two emulator ports.
2. Impairments – Standard impairments include jitter, delay, packet loss, fragment and bandwidth restriction. These impairments can be added in the network and application performance can be checked.
3. Modifiers – Modifiers enable the network emulator to corrupt field values and change the packet delivery information to see if the application can overcome it without crashing or getting stuck.
4. Routing – It forwards packets out of the emulator using different techniques.

Final Deliverable of the Project HW/SW integrated systemCore Industry ITOther IndustriesCore Technology Augmented & Virtual RealityOther TechnologiesSustainable Development Goals Industry, Innovation and InfrastructureRequired Resources

Item Name	Type	No. of Units	Per Unit Cost (in Rs)	Total (in Rs)
			Total in (Rs)	5300
Project Report	Miscellaneous	2	1000	2000
Router	Equipment	2	1500	3000
LAN cables	Equipment	2	150	300