The Netropy N91 Network Emulator offers advanced capabilities to benchmark, troubleshoot, and optimize the performance of critical applications. Netropy’s unique, high-performance Emulation Engine enables high-precision emulation of up to 15 separate WAN links in each of four 1 Gbps Emulation Engines to model complex network topologies or run multiple concurrent tests.

The Netropy N91 is configured and managed through an intuitive, browser-based interface for easy operation, or through a comprehensive command line interface for integration with test automation tools.

The Netropy N91 includes 4 separate 1 Gbps Emulation Engines, ideal for concurrent testing or multiple users.


  • •  Bandwidth
  • •  Latency & jitter
  • •  Packet loss
  • •  Congestion
  • •  Other impairments

Netropy N91 Capacity

  • •  Four 1 Gbps Emulation Engines
  • •  15 separate links per Emulation Engine (60 links total)
  • •  Packets assigned to individual link by any combination of IP address, VLAN, MPLS label, port number, or any other packet field.
  • •  Aggregate 8 Gbps capacity at full line rate
  • •  Eight Gigabit Ethernet ports: Copper or SFP
  • •  Compact, 1U-sized appliance

Easy to Use

The Netropy N91 Network Emulator is quick to install, intuitive to configure, and easy to operate. The Netropy GUI provides the responsiveness of an application with the convenience of a standard web browser.

Multiple Links

The Netropy N91 simulates up to 15 separate WAN links through each of 4 separate 1 Gbps Emulation Engines. Packets are assigned to individual links by IP source and destination address range (IPv4 or IPv6), VLAN, MPLS label, application port number, or any other packet field.

Multiple Emulation Engines

Take advantage of 4 separate 1 Gbps Emulation Engines for concurrent testing or multi-user environments.

Bandwidths up to 1 Gbps

Accurately simulate links from 100 bits per second up to 1 Gbps. Versions also available with maximum emulation speeds of 10 Mbps, 45 Mbps, 100 Mbps for users who do not need the full gigabit capacity.

Latency up to 10 sec.

Emulate delay and jitter up to 10 seconds, in increments of 0.01 ms, with a constant, normal, exponential, or uniform distribution.

Packet Loss and Corruption

Set random, burst, or periodic packet loss, or a bit error rate. Test the effect of data corruption on voice and video applications.

Capture and Replay Live Network Conditions

Capture live network conditions with the Netropy Recorder and replay them through the Netropy Network Emulator to reproduce the dynamic delay and loss characteristics of the production network in a repeatable test environment.

Replay PCAP Files as Background Traffic

Test how applications run over a congested network without costly traffic generators or a rack full of client machines using Netropy's unique background utilization feature that replays PCAP files as background traffic. Each PCAP stream can replicated to simulate large numbers of users or scaled to adjust the timing and bandwidth usage.

Data Visualization

Graph or download up to 24 hours of throughput and other link statistics to visualize and troubleshoot application performance.


Install each emulation engine as either a bridge or router for easy integration with any test configuration.

Copper or SFP interfaces

The Netropy N91 is available with 8 copper RJ45 Gigabit Ethernet ports, 8 SFP Gigabit Ethernet ports, or 4 of each, for convenient installation on copper or fiber-based networks.

Automated Testing

Automate testing using the comprehensive command line interface.

User Controls and Security

Use SSL or SSH for secure access to the Netropy interface. Individual users can lock their engine to prevent configuration changes by any other user. Set user passwords on the device or take advantage of an LDAP server.

Unsurpassed Precision

Test with confidence - the high-precision Netropy Emulation Engine ensures accurate and reproducible results.

Self Monitoring

The Netropy Emulation Engine monitors internal processing and buffering resources to guarantee testing validity.

Priced Right

Get the functionality and performance you need at a price you can afford. Available with a maximum emulation speed of 10 Mbps, 45 Mbps, or 100 Mbps as well as 1 Gbps for users who don't need the full gigabit-speed capacity of the N91.

Everything You Need

Apposite makes buying easy by including everything in one low price. No additional hardware, software, or training required.

With the ability to simulate up to 15 separate WAN links on each of the four Emulation Engines, the Netropy N91 has a myriad of uses:

Emulate multi-site networks

Model a full enterprise network of regional, branch, and local offices, telecommuters, and partners, all connected to headquarters or centralized datacenter.

  1. View applications as they will be seen by different end users
  2. Verify the operation of application servers with concurrent users

Side-by-side benchmarking

Run separate tests side-by-side to:

  1. View the effects of different conditions on application responsiveness
  2. Compare products from different vendors
  3. Tune application settings
  4. Analyze the benefits of acceleration and optimization products

Isolate individual applications

Segregate traffic from individual devices and apply impairments to specific applications

Concurrent testing

Complete a matrix of conditions by running multiple tests in parallel

Multiple Users

With four independent Emulation Engines, each with their own Gigabit Ethernet interfaces, it’s easy to share a single unit across multiple users or separate organizations.

User Interface

Netropy advanced network emulators are quick to install and easy to operate. Configuration requires only a few simple steps through the intuitive, browser-based GUI.

Netropy N91 Monitor

Netropy main configuration and monitoring window.

Path Configuration

Set the bandwidth, delay, loss, and other network conditions for each link in the Path Configuration window.

Path Configuration

Direct packets onto individual links by IP address, VLAN, or other packet fields in the Classifier Configuration window.

Network design

Build "what-if" scenarios to choose between private lines, internet VPNs, and wireless and satellite networks to connect offices across the globe, and determine how much bandwidth to purchase to ensure critical applications perform as needed.

Application validation

See how applications will perform prior to roll-out and avoid unpleasant surprises and panic fixes later.

Vendor selection

Compare products from different vendors to select the one that works best on your network.


Adjust application settings to optimize performance for different end users.


Analyze the benefits of WAN acceleration products to optimize the existing infrastructure.


Pinpoint the cause of reported problems and complaints, then validate potential solutions without disrupting the production network.

Emulation Capabilities
Packet Classification IP source and destination address range
IPv6 source and destination address range
VLAN ID and PCP prioritization value
IP ToS: Precedence or DSCP value
TCP or UDP port number
MAC address
MPLS address
Any arbitrary field specified by layer, offset, length, and mask
Bandwidth 100 bps to max. license speed in 1 bps increments
Latency & jitter 0 ms – 10,000 ms. in 0.01 ms increments;
constant, uniform, exponential, normal distributions with or without reordering;
accumulate & burst delay;
replay recorded latency from Netropy Recorder or file
Loss and Corruption random, burst, periodic, BER, Gilbert-Elliott, or recorded packet loss;
packet data corruption
Queuing and Prioritization RED, tail drop, and round robin queue management;
Priority or Round Robin queuing based on IP ToS or VLAN PCP value
Additional packet reordering, packet duplication, MTU and fragmentation,
frame overhead, separate inbound and outbound rate control
Max. Link Emulation Speed Available in 10 Mbps, 45 Mbps, 100 Mbps, and 1 Gbps versions.
Emulate any speed up to licensed maximum.
Emulation Engines 4
Max. Aggregate Throughput 8 Gbps
Maximum Packet Rate 1.488 million packets per second per port (full line rate)
11.9 million packets per second aggregate
Maximum Frame Size 9 KB
Emulation 8 Gigabit Ethernet (8 copper, 8 SFP, or 4 of each)
Management 1x Gigabit Ethernet
1x RS-232 serial console
Environmental and Physical Specifications
AC Input Voltage Auto ranging 100 VAC to 240 VAC
AC Input Frequency 50 to 60 Hz
AC Input Current 1.0 A
Power Draw 120 Watts
22" D x 17.0" W x 1.75" H (1 RU)
56 cm D x 43 cm W x 4.4 cm H (1 RU)

29" D x 23" W x 8" H
73 cm D x 58 cm W x 20 cm H

18 lbs. (8 kg)
29 lbs. (14 kg)

32° to 104°F (0° to 40°C)
-4° to 158°F (-20° to 70°C)
Humidity 5% to 95% (non-condensing)
Certifications FCC Class A, CE, RoHS
Warranty & Support
Hardware Warranty 1 year
Support and Maintenance 1 year, including all firmware upgrades
Ordering Information
Part Numbers 10 Mbps version: N91-10M
45 Mbps version: N91-45M
100 Mbps version: N91-100M
1 Gbps version: N91-1G
SFP ports option unit comes standard with 8 RJ45 ports for emulation
N91-SFP: 8 SFP ports
N91-C4S4: 4 SFP ports and 4 RJ45 ports