Network emulation
From Wikipedia, the free encyclopedia
Network emulation is a technique where the properties of an existing, planned and/or non-ideal network are simulated in order assess performance, predict the impact of change, or otherwise optimize technology decision-making.
This 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] Free software
- Dummynet is a flexible tool originally designed for testing networking protocols. It is part of the current FreeBSD system.
- 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 RedHat distribution of NISTnet is available from Cisco Systems.
- NS-2 is a popular network simulator that can also be used as a limited-functionality emulator. It is currently maintained.
- NetEmulator is an emulator developed at MITRE that was donated to open source. It is comparable to NISTNet and is maintained.
[edit] Commercial software
- Itheon Network Emulator The affordable high performance emulator enabling you to test all critical network conditions prior to rolling out applications. Can emulate Gigabit, Satellite, Fiber, Wireless, VoIP and many other network types and applications.
- Shunra VE Desktop runs on Microsoft Windows and simulates a network link, including latency, bandwidth, jitter and packet loss conditions.
- LANforge-ICE WAN Emulator runs on Linux and Microsoft Windows and supports bandwidth-constraints from 4 kbit/s to 1 Gbit/s, latency, jitter, packet loss/duplication/reordering and more.
- NetSim runs on Linux and Microsoft Windows and simulates networks and applications. Covers Ethernet, Wireless LANs, TCP, OSPF, RIP, ATM .....
[edit] Commercial devices
- Anue Network Emulator, precision hardware based network emulators for Gigabit and 10 Gigabit Ethernet, SONET/SDH, Fibre Channel, CPRI and G.709.
- Shunra Virtual Enterprise, a comprehensive network simulation suite that simulates the network, remote locations, and the number and distribution of local and remote end-users for application and network testing.
- Apposite Technologies provides WAN emulation for terrestrial, wireless, and satellite links
- Packet Storm provides emulation at up to gigabit speeds
- Network Nightmare provides low end (< 20 Mbit/s) emulation
- Itheon Network Emulator provides Gigabit (10/100/1000) network environment emulation
- LANforge-ICE WAN Emulator supports bandwidth-constraints from 4 kbit/s to 1 Gbit/s, latency, jitter, packet loss/duplication/reordering
- Simena Network Emulator and Traffic Generator provides complete list of high speed network impairments, along with traffic injection, traffic capture&replay, and RFC 2544 based network measurements.
- Maxwell, from InterWorking Labs, creates protocol impairments, not just packet impairments, on multiple, concurrent flows of network traffic
