Introduction to modeling and simulation of networks#
A network simulator1 enables users to virtually create a network comprising of devices, links, applications etc., and study the behavior and performance of the Network.
Some example applications of network simulators are:
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Protocol performance analysis
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Application modeling and analysis
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Network design and planning
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Research and development of new networking technologies
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Test and Verification
The typical steps followed when simulating any network are:
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Building the model: Create a network with devices, links, > applications etc.
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Running the simulation: Run the discrete event simulation (DES) > and log different performance metrics.
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Visualizing the simulation: Use the packet animator to view the > flow of packets.
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Analyzing the results: Examine output performance metrics such > as throughput, delay, loss etc. at multiple levels - network, > link, queue, application etc.
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Developing your own protocol / algorithm: Extend existing > algorithms by modifying the simulator's source C code.
Versions of NetSim -- Academic, Standard & Pro#
NetSim is used by people from different areas such as industry, defense, and academics to design, simulate, analyze and verify the performance of different networks.
NetSim comes in three versions: Academic, Standard and Pro. The academic version is used for lab experimentation and teaching. The standard version is used for R&D at educational institutions while, NetSim Pro version addresses the needs of defense and industry. The standard and pro versions are available as components in NetSim v13.2 from which users can choose and assemble. A comparison of the features in the three versions are tabulated below Table 1‑1.
| Features | Academic | Standard | Pro |
|---|---|---|---|
| Technology Coverage | |||
| Internetworks | Y | Y | Y |
| Legacy & Cellular Networks | Y | Y | Y |
| Mobile Adhoc networks | Y | Y | Y |
| Software Defined Networks | Y | Y | Y |
| Wireless Sensor Networks | Y | Y | Y |
| Internet of Things | Y | Y | Y |
| Cognitive Radio Networks | Y | Y | Y |
| LTE Networks | Y | Y | Y |
| 5G NR | N | Y | Y |
| VANET | N | Y | Y |
| Satellite Communication Networks | N | Y | Y |
| Underwater Acoustic Networks | N | Y | Y |
| Performance Reporting | |||
| Performance metrics available for Network and Sub-networks | Y | Y | Y |
| Packet Animator | |||
| Used to animate the packet flow in network | Y | Y | Y |
| Packet Trace | |||
| Available in tab ordered .csv format for easy post processing | Y | Y | Y |
| Event Trace | |||
| Available in tab ordered .csv format for easy post processing | N | Y | Y |
| Protocol Library Source Codes with Documentation | |||
| Protocol C source codes and appropriate header files with extensive documentation | N | Y | Y |
| External Interfacing | |||
| Interfacing with SUMO | N | Y | Y |
| MATLAB | N | ||
| Wireshark | Y | ||
| Integrated debugging | |||
| Users can write their own code, link their code to NetSim and debug using Visual Studio | N | Y | Y |
| Plots | |||
| Allows users to plot the value of a parameter over simulation time | Y | Y | Y |
| Simulation Scale | 100 Nodes | 500 Nodes | ~ 10,0000 Nodes |
| Custom Coding and Modeling Support | N | Y | Y |
| Emulator (Add on) | |||
| Connect to real hardware running live application | N | Y | Y |
| TDMA Radio Networks (Add On) | |||
| TDMA and DTDMA | N | N | Y |
| Target Users and Segment | Educational (Lab Experimentation) | Educational (Research) | Commercial(Industrial and Defense) |
Table 1‑1: A comparison of the features of NetSim Academic, Standard and Pro versions
Components (Technology Libraries) in Pro and Standard versions#
| Component No | Networks / Protocols Supported | Reference International Standards |
|---|---|---|
| Component 1(Base. Required for all components) | Internetworks Ethernet - Fast & Gigabit, ARP, Routing - RIP, OSPF, WLAN - 802.11 a / b / g /p / n / ac & e, Propagation models - HATA Urban / Suburban, COST 231 HATA urban / Suburban, Indoor Home / Office / Factory, Friis Free Space, Log Distance. Shadowing - Constant, Lognormal. Fading - Rayleigh, Nakagami IPv4, Firewalls, Queuing - Round Robin, FIFO, Priority, WFQ, TCP, - Old Tahoe, Tahoe, Reno, New Reno, BIC, CUBIC, Window Scaling, SACK UDP Common Modules Traffic Generator: Voice, Video, FTP, Database, HTTP, Email, P2P, Custom, CBR. Virtual Network Stack, Simulation Kernel, Command Line Interface Command Line Interpreter Metrics Engine with packet and event trace Plot Generator Packet Animator, Packet Encryption External Interfaces: MATLAB, Wireshark | IEEE 802.3 IEEE 802.11 a/b/g/n/ac/p/e RFCs 2453, 2328, 826, 793, 2001 and 768 |
| Component 2 | Legacy & Cellular NetworksAloha – (Pure & Slotted) GSM CDMA | 3GPP, ETSI, IMT-MC, IS-95 A/B, IxRTT, 1x-EV-Do, 3xRTT |
| Component 3 | Advanced Routing Multicast Routing - IGMP, PIM, Access Control Lists, Detailed Layer 3 switch mode, Virtual LAN (VLAN), Public IP, Network Address Translation (NAT) | IETF RFC’s 1771 & 3121 |
| Component 4 | Mobile Adhoc Networks MANET - DSR, AODV, OLSR, ZRP | IETF RFC 4728, 3561, 3626 |
| Component 5 | Software Defined Network (SDN) | Based on Open Flow v1.3 |
| Component 6 (Component 4 required) | Internet of things (IOT) with RPL protocol Wireless Sensor Networks (WSN) | IEEE 802.15.4 MAC, MANET in L3 RFC 6550 |
| Component 7 | Cognitive Radio Networks WRAN | IEEE 802.22 |
| Component 8 | Long-Term Evolution Networks: LTE | 3GPP |
| Component 9 (Component 4 required) | VANETs: IEEE 1609 WAVE, Basic Safety Message (BSM) protocol per J2735 DSRC, Interface with SUMO for road traffic simulation | IEEE 1609 |
| Component 10 (Components 8 required) | 5G NR :3GPP 38 Series. Full Stack covering SDAP, PDCP, RLC – UM, TM, MAC, PHY – FR1 and FR2, mmWave propagation. | 3GPP 38.xxx |
| Component 11 (Component 3 required) | Satellite Communication Networks: Geo Stationary Satellite. Forward link TDMA in Ku Band and Return link MF-TDMA in Ka band per DVB S2. Markov Loo Fading model. Device models for Satellite, Satellite Gateway, and Satellite User Terminals | DVB S2 |
| Component 12 (Component 2 & 3 required) | Underwater Acoustic Network | IEEE 802.11 |
| TDMA Radio Networks Add on (Pro version only) | TDMA Radio Networks TDMA Link 16, Dynamic TDMA, Frequencies – HF, VHF, UHF Bands,Frequency Hopping | ---- |
| Network Emulator Add On | Network Emulator Connect real hardware running live applications to NetSim Simulator. IP based, data plane, flow through emulator. | ---- |
Table 1‑2: Different Components (Technology Libraries) in Pro and Standard versions of NetSim
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To be technically precise, NetSim is an end-to-end, full-stack, packet level, continuous time, discrete event network simulator. ↩