5 Requirements Your Network Emulator Tool Must Satisfy

As communication networks become ubiquitous, there is continuous innovation both in the technologies they employ and the services they are expected to provide, creating new challenges for equipment manufacturers, service providers, network planners, and operators. Network emulation can assist in addressing many of these challenges, including:

• Examining network behavior thoroughly in various operational scenarios, including different types and quantities of traffic (e.g., voice, video, file transfer). This analysis aids in pinpointing potential issues, understanding their underlying causes, and assessing potential solutions before implementation.

• Providing a zero-risk, low-cost means to assess the cyber resilience of the network.

• Assisting developers of new applications and services by providing a low-cost testbed to evaluate their performance under different conditions (e.g., mobility in dense urban terrain) and to assess their interoperability with competing applications (e.g., potential interference between a multiplayer video game and voice-call handoff).

In order for a Network Emulator Tool to add value and provide a high return on investment for users — network operators, planners, designers, testers, or analysts — it must satisfy the following requirements:

Accuracy

Network emulations must be able to accurately reproduce the behavior of the corresponding network as it operates in the field. To achieve this, the simulator must model the network devices, end-to-end protocols, traffic, and the operational environment accurately and at the appropriate fidelity. Emulators that use abstractions to reduce model execution time (e.g., by ignoring terrain effects buffer size or bursty traffic patterns) will fail to capture the network dynamics which significantly affect network performance and lead to potential issues like congestion, voice quality degradations, or failures.

Speed and Scalability

Multiple emulation runs are typically needed to obtain statistically valid and meaningful results, so fast execution speed — without sacrificing accuracy — is essential. As network size increases, the emulation time often increases non-linearly with size and traffic volume. As network dynamics of large networks are very different from smaller networks, extrapolation of results obtained by simulating small networks to larger networks is difficult. Therefore, for the simulation tool to be useful, it must be able to run ‘at-scale' models faster than in real time without sacrificing accuracy.

Ease of Creating Emulation Models

Developing high-fidelity models of network devices and protocols from scratch is time-consuming and also requires detailed networking knowledge together with programming expertise. Thus, to provide a high return on investment, network simulators must facilitate rapid model creation.

• The emulation tool should provide a library of pre-built, accurate models of a diverse set of network components that are easy to customize, such that the resulting model is an accurate representation of the target network. The model library should include models for Devices such as routers, servers, access points, base stations, hosts, mobile devices, radios, etc.

• Common applications, such as web browsing, email, messaging, database transactions, file transfer, video conferencing, VoIP, etc.

• Wired networks and wireless communication technologies such as Wi-Fi, WiMax, cellular (GSM, UMTS, LTE, 5G), satellites, etc.

• Cyberattacks and defenses, and host vulnerabilities which can be exploited by cyber threats

• Protocols at all layers of the protocol stack, including routing protocols used in different domains, protocols for QoS provisioning, MAC protocols, etc.

• Environmental factors that affect wireless communications, such as terrain and weather effects, and mobility patterns of mobile devices

• The network simulator must provide an intuitive GUI to rapidly create complete scenarios from the library of network components.

• It must be easy to modify the operational parameters of a ‘baseline' scenario and create different ‘what-if' scenarios.

• To analyze existing or ‘as-is' networks, it should be easy to develop emulation models from representations of the networks in popular, standard formats, such as Visio files. This will ensure that the model accurately represents the network being analyzed.

• To enable accurate modeling of network traffic, the emulation tool should support the import of representations or traces of traffic from operational networks and faithfully reproduce it in the emulation model, for example, by importing PCAP files generated by Wireshark or other similar tools.

Ease of Network Visualization and Performance Analysis

The results from a network emulation are used for network analysis and to provide insight into network operations. To facilitate this, the emulation tool should have the following features:

• A database of comprehensive and detailed statistics that can be used after the emulation to generate actionable reports. These are essential for identifying issues, understanding the root cause, and comparing alternative mitigations.

• An operational visualization capability to provide an overview of network operations by displaying end-to-end packet transfers and key statistics which are updated dynamically as the emulation is running. Such visualization can help understand the interactions between different applications.

• A technical visualization interface that provides details of network operations by graphically displaying network performance metrics like coverage heat maps, the paths traversed by packets, states of queues, etc. Such visualization can be very useful to identify and resolve performance issues, such as network congestion.

• Interface to third-party analysis, data visualization, and report generation tools, such as Tableau

Ability to Interface with Live Applications

The network emulation must be able to interface with live network components and real applications. This in turn requires that the emulation run in hard real-time. In other words, the application will interact with the simulated network exactly as it interacts with the corresponding live network. This enables an analyst to directly assess the application's performance under different operating conditions, such as different terrains or mobility paths, simply by modifying the appropriate parameters of the network model. Similarly, such emulations can be used to investigate potential interference among applications under different operating conditions like varying levels of traffic intensity. This provides a low-cost and high return on investment alternative to performing such assessments using physical testbeds.

KEYSIGHT EXata network digital twin solution can run accurate, at-scale network emulations faster than real-time, support an extensive library of network models and provide a suite of tools for scenario creation and network visualization and analysis.