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IPLinkSim™ - IP WAN Link Emulator

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Generally today’s applications are intended to work on different networks such as enterprise networks, storage, cloud services, web services, ftp, audio/video streaming, etc.  Typically, such applications have a client and server components, communicating over a Wide Area Network (WAN) link, whether it be mobile browsing (http, ftp etc.), VoIP, IPTV over the public internet, or database access via the corporate intranet. Application developers can easily test their applications on a local LAN, but require testing with the realistic network conditions prior to live deployment. Conducting tests on real WAN links is expensive or simply not feasible in most cases. IP WAN Link Emulators help to test the performance of such WAN network-dependent applications by emulating the WAN conditions in a local setup easily and cost effectively.

GL’s IPLinkSim™ is a simple-to-use IP WAN (Wide Area Network) link simulator that comes in 2 platform variants –

  • IPLinkSim™ 1 Gbps (IPN110) – This is a quad port USB based portable unit, of which 2 are 10/100/1000Mbps Electrical or Optical (Port 2, Port 3) and the other 2 are Electrical only. IPLinkSim™ supports WAN link simulation on these 10/100/1000Mbps Electrical or Optical ports only. This can emulate a bidirectional IP WAN link with varying capacities from 10 Mbps to 1 Gbps for the electrical interfaces, and 1000 Mbps for the optical interface
  • IPLinkSim™ 10 Gbps & 1 Gbps (IPN510) - This is a quad port USB based portable unit, of which 2 are 10 Gbps optical ports, and other 2 are 10/100/1000Mbps Electrical / Optical ports. IPLinkSim™ supports WAN link simulation on both these ports. IPLinkSim™ can be configured to simulate a single bi-directional link between two active ports on both 1 Gbps Electrical/Optical ports and 10 Gbps Optical only ports.

Simply connect IPLinkSim™ unit in series with existing optical or electrical links, and introduce any impairment type to test the various applications in the lab prior to live deployment.

 IPLinkSim™ provides several such as user defined Bandwidth throttling, Congestion emulation, Latency, Packet Loss, Packet effects, Packet Corruption etc.  Bandwidth Throttling simulates slower WAN links like RS232/DSL/Modem/T1/E1/T3/E3 etc. This feature allows testing applications running in PCs which normally have higher capacity interface but access to the outside internet or intranet over WAN is very slow. Congestion in the network can be emulated with generating an additional background traffic in addition to the traffic of interest. Latency can be used to recreate the constant or varying delay caused by various factors in the network.

Typically, WAN links suffer from Packet effects such as Packet Loss, Packet Corruption, Packet Duplication and Packet reordering with additional burden on end to end applications to compensate for these impairments. Such frames are dropped at end points causing retransmissions. IPLinkSim™ provides features to emulate these Packet effects.

Other variants of Ethernet/IP tester includes HD PacketExpert™ (PXE112 or PXE124) that offers higher densities of 12/24 GigE ports form factor solution for testing GigE switches, routers and network conditions. This multi-device hardware unit incorporates all the features of a single quad port IPLinkSim™ unit along with the necessary PC hardware with Windows® OS and remote accessibility via Ethernet Remote Desktop. The High-density PacketExpert™ supports up to 6 WAN links offering you multiple independent WAN links directly, with which you can compare and demonstrate application performance on different types of networks.

PacketExpert™ also supports Command line Interface (CLI) to access all the IPLinkSim™ functionalities remotely such using TCL clients and MAPS™ CLI client/server architecture.

Main Features

  • Easy- to-use portable hardware based WAN Link Emulator.
  • Emulates 1 bidirectional WAN Link per IPLinkSim™ unit.
  • Emulate WAN link conditions separately and independently for each direction. Acts as a transparent bidirectional link or a simple Ethernet Bridge for easy integration with any test setup.
  • Easily monitor the bandwidth performance using live throughput graphs, and per-port or per-link statistics.
  • Check the stability or performance of the network with various real world impairments including
    • Bi-directional Delay in milliseconds increments (0 milliseconds to 8 seconds – constant delay, uniform, random distributions and Delay variation (Jitter)) to emulate various wired, wireless, and network elements.
    • Congestion Emulation with Background traffic (% of total bandwidth)
    • Packet Loss (loss rate % of total packets 0–100%)
    • Packet Reordering (reordering rate (0-100%) with Min & Max Delay range)
    • Packet Duplication (percentage of total packets duplicated 0 - 100%)
    • Logic Error and FCS Error insertion (10-1 to 10-9 error rate) within Ethernet packet to emulate faulty network devices or interference 
  • Bandwidth control to emulate various WAN link speeds
  • Supports transmission of Ethernet Pause frame with user-defined quanta used to throttle Ethernet link overload.
  • Command Line Interface for automated testing and remote accessibility.


  • Evaluate performance of enterprise-level, and bandwidth-sensitive applications prior to deployment
  • Test Audio, and Video quality on IP networks
  • Estimate bandwidth and QoS requirements

Other Related Products

IPNetSim(IPN501) appliance is a 1U rack-mount hardware unit that simulates a single WAN link on the two 1 Gbps ports with unique multi-stream capability. It includes features such as bandwidth throttling, congestion, latency, packet loss, packet duplication, dropped packets, packet corruption etc. Up to 16 bi-directional independent streams are supported. 

IPNetSim™ (IPN505) available as a portable Touchscreen handheld unit sports the same features as IPN501. 

GL’s IPNetSim™ Handheld (IPN701) is a hand-held battery operated instrument that can simulate the real-time IP and Carrier Ethernet network dynamics by means of hardware controlled packet delay, loss, jitter, errors, bandwidth limitations, congestion, and duplication. IPNetSim™ Handheld offers to manage network behaviours of up to 1 Gbps rates with accuracy always better than 1ms. Up to 16 bi-directional independent streams are supported. 

Hardware Interface - PacketExpert™ 10G

PacketExpert™ Hardware Unit

Front Panel

Back Panel

  Standalone Tablet Inspired


  • 2 x 1G Base-X Optical OR 10/100/1000 Base-T Electrical
  • 2 x 10G Base-SR, -LR -ER Optical only
  • Single Mode or Multi Mode Fiber SFP support with LC connector


  • RFC 2544 compliance

Bus Interface:

  • USB 2.0
  • None or USB 2.0

External Power Supply:

  • +12 volts, 2.2 Amps
  • +18 Volts, 3.0 Amps

Physical Specification:

  • Length: 6.39 in. (162.33 mm)
  • Width: 9.96 in. (252.93 mm)
  • Height: 2.10 in (53.34 mm)
  • Weight: 3.75 lbs. (1.7 kg)
  • Length: 6.39 in. (162.22 mm)
  • Width: 9.96 in. (252.93 mm)
  • Height: 2.59 in (65.96 mm)
  • Weight: 4.75 lbs. (2.15 kg)


Hardware Interface - PacketExpert™ 1G

Back Panel

Front Panel


  • 2 x 10/100/1000 Base-T Electrical only
  • 2 x 1000 Base-X Optical OR 10/100/1000 Base-T Electrical
  • Single Mode or Multi Mode Fiber SFP support with LC connector


  • RFC 2544 compliance

Bus Interface

  • USB 2.0


  • +9 volts, 2.2 Amps


  • Operating Temperature: +5 to +40C
  • Non-Operating Temperature: -30 to +60C


  • Operating Humidity: 0% to 80% RH
  • Non-Operating Humidity: 0% to 95% RH


  • Operating Altitude: Up to 10,000 feet
  • Non-Operating Altitude:  Up to 50,000 feet

Physical Specification

  • Length: 8.45 in. (214.63 mm)
  • Width: 5.55 in. (140.97 mm)
  • Height: 1.60 in (40.64 mm)
  • Weight: 1.66 lbs. (0.75 kg)

WAN Link Impairments

GL's IPLinkSim™ WAN link emulator is capable of emulating a WAN link, and introducing typical WAN impairments like Bandwidth Throttling, Latency, Jitter, Packet Loss, Packet Reordering, Packet Duplication, Packet Corruption, Congestion Emulation etc.

IPLinkSim™ supports single stream only, and applies the impairments to the traffic. In addition to the above impairments, IPLinkSim™ also supports congestion emulation by allowing background traffic emulation. 

The link emulator has the capability to better model real-world impairments with Periodic and Random options, which are briefly discussed below:

Bidirectional WAN link Emulation

Packet Loss Impairment

Screen shot of Packet Loss model configurations

Packet Loss can be introduced either as a rate as well as Manually. For both rate and manual, user can choose to drop a single packet or a burst of packets, at a time.

  • Rate: User can configure the Loss rate, and packets will be dropped at that rate. User can choose a periodic loss, where the packet drops will be regular and predictable, or random packet loss, where packets will be dropped randomly. For both periodic as well as random packet loss, the overall packet loss rate is maintained, but only the way the packets selected for dropping is changed

  • Manual Drop: This allows user to manually drop either a single packet or burst of packets at run time. This drop will be in addition to the rate loss, if active.

  • Single vs Burst Drop: In Single drop, only one packet will be dropped at a time. However, Real world Packet Loss is many times bursty in nature i.e. a bunch of consecutive packets are lost. This allows user to drop a burst of packets at a time instead of a single packet i.e. a bunch of consecutive packets are lost. To emulate such conditions, Burst Packet Loss can be configured

Packet Reordering

Screen shot of Packet Reorder model configurations

Packet reordering model includes Periodic and Random Packet Reordering options.  In Periodic option, the packets are reordered at constant specified rate. While in Random option, packets are randomized for reordering, but still maintain the specified Reorder rate.

Once a packet has been selected for reordering, it will be held for a certain amount of time before being reinserted into the stream. The delay can be configured in terms of time (milliseconds), or Packet offset (number of frames). During Packet offset delay, the reordered frame will be held until the configured offset frames are received, before being reinserted into the stream. The offset selected at run time will be a random value between the maximum and minimum defined value range.

The Packet Reordering model also includes Manual Packet Reorder option to reorder a packet instantaneously at run time. When selected, it will immediately reorder a single packet.

Packet Duplication

Screen shot of Packet Duplication model configurations

Packet Duplication model also includes Periodic and Random Packet Duplication options. In Periodic Duplication option, the packets are duplicated at specified rate periodically. In Random Duplication option, the selected packet is duplicated (based on the rate) randomly, but maintaining the duplication rate.

A single packet can be duplicated instantaneously at run time with Manual Packet Duplication option.

Packet Error Insertion

Screen shot of Packet Error Insertion model configurations

Packet Error Insertion model also includes Periodic and Random Packet Error Insertion options. In Periodic Error Insertion option, the start of frame and end of frame byte offsets specifies where exactly in the frame to inject errors. In the Random Error Insertion option, the packet will be randomly selected for error insertion (based on the rate), but the error insertion rate is maintained.

But in Manual Error Insertion option, error is introduced into a single packet at run time manually.

Working Principle - PacketExpert™ 10G

IPLinkSim™ on 10G/1G unit can be configured to act as a transparent bidirectional Ethernet link or a simple Ethernet bridge between 2 Ethernet end points. The links are emulated between Port 1 (P1) and Port 2 (P2). Currently IPLinkSim™ 10G is limited to emulate only constant bandwidth of 1 Gbps on 1 GigE ports and 10 Gbps on 10 GigE ports. Ability to emulate varied bandwidth is coming soon..P1 -> P2 is one link and in the reverse direction, i.e., P2 -> P1 forms the other link. By default, P1 and P2 work in pass-through mode, and pass all frames across to the other port. Frames arriving at P1 are carried over to P2 and frames arriving at P2 are carried over to P1.

Transparent Bidirectional Link (P1-P2)/(P2-P1)

On the emulated WAN links, you can choose to simulate the different link conditions (such as Bandwidth Control, Background Traffic, Latency, Error Insertion) emulating real-world scenarios.

PacketExpert 10G™ (WAN Emulator) connecting 2 network end points

Impairments over P1->P2 and P2->P1 Link

Working Principle - PacketExpert™ 1G

IPLinkSim™ on exclusive 1G PacketExpert™ unit simulates bidirectional P2 <-> P3 single link between Port 2 (P2) and Port 3 (P3). By default, P2 and P3 work in pass-through mode, and pass all frames across to the other port. Frames arriving at P2 are carried over to P3 and frames arriving at P3 are carried over to P2.

Transparent Bidirectional Link (P2-P3)/(P3-P2)

Similar to IPLinkSim™ 10G, on the emulated WAN links, you can choose to simulate the different link conditions (such as Bandwidth Control, Background Traffic, Latency, Error Insertion) emulating real-world scenarios.  However, you have complete control over the bandwidth (from 300 bps up to 1000 Mbps) to emulate various WAN link speeds (Modem, DSL, T1/E1/T3/E3/OC3/OC12 etc).

PacketExpert™ (WAN Emulator) connecting 2 network end points

1G Link Emulation

Link Statistics

This option provides real-time transmission statistics of the traffic over the emulated link (P2-P3)/(P3-P2) in each direction. The statistics parameters include Dropped Packets (Bandwidth Control), No. of Packets with Errors, Dropped Packets (Packet Loss), Duplicated Packets, Reordered Packets, and Background Traffic Bandwidth, for varying durations.

1G Link Statistics

10G Link Statistics

Link Throughput Graph

The graph displays the real-time Throughput of the link, plotted as rate against time, in the form of a line graph.  The Graph can be viewed for a single link or both the links together.

1G Link Graph

10G Link Graph

Buyer's Guide

Please Note: The XX in the Item No. refers to the hardware platform, listed at the bottom of the Buyer's Guide, which the software will be running on. Therefore, XX can either be ETA or EEA (Octal/Quad Boards), PTA or PEA (tProbe Units), UTA or UEA (USB Units), HUT or HUE (Universal Cards), and HDT or HDE (HD cards) depending upon the hardware.

Item No. Item Description


IPLinkSim™ WAN Link Emulator
(1 Gbps, 2 active ports)


IPLinkSim™ WAN Link Emulator
(10/1 Gbps, 2 active ports)


Related Hardware


IPNetSim™ 1G (Multi-stream)


IPNetSim™ 1G Tablet  (Multi-stream)


IPNetSim™ Handheld Network Impairment Generator 
IPNetSim™ Handheld Remote Option


Related Software


PacketBroker™ - 1G
PacketBroker™ - 10G


Multi-Stream Traffic Generator and Analyzer - 1G (on PXE100) (up to 12 users)
Multi-Stream Traffic Generator and Analyzer - 10G (on PXG100, PXG101) (up to 16 users)


PacketExpert 10G™


PacketExpert 10G™ with Tablet


PacketExpert™ - SA (4 ports) 
PacketExpert™ - SA (12 Ports)
PacketExpert™ - SA (24 Ports)


Wire speed Record /Playback - 1G
Wire speed Record /Playback - 10G


ExpertSAM™ - 1G
ExpertSAM™ - 10G


Related Software




PacketGen™ (includes PacketScan™)


PacketScan™ (Online and Offline)


RTP ToolBox™


MAPS™ SIP Emulator 
MAPS™ SIP Conformance Test Suite (Test Scripts)
MAPS™ MEGACO Conformance Test Suite (Test Scripts)
MAPS – MGCP Protocol Emulation with Conformance Test Suite

* Specifications are subject to change without notice

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