Network emulation
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Network emulation is a technique where the properties of an existing, planned and/or non-ideal network are simulated in order to assess performance, predict the impact of change, or otherwise optimize technology decision-making.
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[edit] Methods of emulation
Network emulation can be accomplished by introducing a device on the LAN that alters packet flow in a way that imitates the behavior of application traffic in the environment being emulated. This device may be either a general-purpose computer running software to perform the network emulation or a dedicated emulation device. The device incorporate a variety of network attributes into its emulation model – including the round-trip time across the network (latency), the amount of available bandwidth, a given degree of packet loss, duplication of packets, reordering packets, and/or the severity of network jitter. Desktop PCs can be connected to the emulated environment, so that users can experience the performance and behavior of applications in that environment first-hand. Similarly, phones can be connected to the emulated environment so that users can directly assess VoIP call quality for themselves.
[edit] Emulation, simulation and traffic generation
Emulation differs from simulation in that a network emulator appears to be a network; end-systems such as computers can be attached to the emulator and will behave as if they are attached to a network. Network simulators are typically programs which run on a single computer, take an abstract description of the network traffic (such as a flow arrival process) and yield performance statistics (such as buffer occupancy as a function of time).
A network emulator emulates the network which connects end-systems, not the end-systems themselves. Systems which emulate the end-systems are called traffic generators.
[edit] Free software
- Dummynet is a flexible tool originally designed for testing networking protocols. It is part of the current FreeBSD system.
- NS-2 is a popular network simulator that can also be used as a limited-functionality emulator. It is currently maintained.
- Modelnet is a scalable network emulator that can emulate thousands of links. Versions are available for FreeBSD and Linux.
- Netem is an optional part of recent Linux kernels. It is currently maintained.
- NISTnet is an emulator for Linux platforms. It is barely maintained by its original NIST author. A Red Hat distribution of NISTnet is available from Cisco Systems.
- WANem [1] is a simple, easy to use network emulator that can emulate a large number of network characteristics. It is a available as a bootable CD and as a virtual appliance. Greearb (talk) 18:43, 3 June 2008 (UTC)
[edit] Commercial software
- Apposite Technologies provides WAN emulation for terrestrial, wireless, and satellite links
- Itrinegy Emulator provides Gigabit (10/100/1000 Mbit/s) network environment (WAN, Wireless, Satellite, GPRS/3G, MPLS) emulation.
- LANforge-ICE WAN Emulator runs on Linux and Microsoft Windows and supports bandwidth-constraints from 10 bit/s to 1 Gbit/s, latency, jitter, packet loss/duplication/reordering and more.
- PacketStorm Communications provides numerous impairments and emulation at up to 10 Gigabit speeds.
- Shunra Software: WAN emulation solutions for application performance testing throughout the entire development lifecycle. Allows you to predict application performance in any production environment—before deployment. A WAN model is built using a Visio interface and then tested using an appliance or software application. The software, VE Desktop Professional, can emulate up to 45Mbps and measures latency, jitter and packet loss. This software provides high level, as well as root cause, analysis reporting. See also: Application Performance Management
- Simena Network Emulator provides complete list of network impairments at gigabit wire speed and with high precision, along with traffic injection, traffic capture and replay, and RFC 2544 based network measurements. Greearb (talk) 18:49, 3 June 2008 (UTC) Greearb (talk) 18:59, 3 June 2008 (UTC)
[edit] Commercial Hardware
- Anue Network Emulator, precision hardware-based network emulators for Gigabit and 10 Gigabit Ethernet, SONET/SDH, Fibre Channel, CPRI and G.709.
- Apposite Technologies provides WAN emulation for terrestrial, wireless, and satellite links
- Itrinegy Emulator provides Gigabit (10/100/1000 Mbit/s) network environment (WAN, Wireless, Satellite, GPRS/3G, MPLS) emulation
- LANforge-ICE WAN Emulator supports bandwidth-constraints from 4 kbit/s to 1 Gbit/s, latency, jitter, packet loss/duplication/reordering
- Network Nightmare provides low end (< 20 Mbit/s) emulation
- PacketStorm Communications provides numerous impairments and emulation at up to 10 Gigabit speeds.
- Shunra Software: WAN emulation solutions for application performance testing throughout the entire development lifecycle. Allows you to predict application performance in any production environment—before deployment. A WAN model is built using a Visio interface and then tested using an appliance or software application. Appliances testing ranges from several 10/100 Ethernet interfaces up to the latest STA appliance supporting 10Gbps service interfaces and a switching capacity up to 24Gbps. The Appliance based solution measures latency, jitter and packet loss, bandwidth, bandwidth utilization and congestion and supports a near limitless number of network topologies including point-to-point, hub and spoke, N-Tier and fully meshed networks. This hardware solution provides high level, as well as root cause, analysis reporting. See also: Application Performance Management
- Simena Network Emulator provides complete list of network impairments at gigabit wire speed and with high precision, along with traffic injection, traffic capture and replay, and RFC 2544 based network measurements. Greearb (talk) 18:57, 3 June 2008 (UTC)
