NetChannel – Key Features

NetChannel supports following features:

  • NetChannel is extremely easy to use, flexible and very powerful.
  • Several network tunnels may be created on one net channel box.
  • Network tunnel end points can be created based on IP address, port, protocol, or literally any bit of the IP datagram.
  • Can emulate network characteristics as defined in next section.

Bandwidth Constraints

Bandwidth represents the capacity of the connection. Bandwidth is represented as data rate supported by a network connection or interface. NetChannel allows to configure the bandwidth constraints in following units:

  • Kilobits per sec (kbps)
  • Megabits per second (mbps)
 1.1If you do not want to put bandwidth constraints, you can use ‘No constraints’ option.

Network Latency

Network latency is a measure of how fast a network is running. The term refers to the time elapsed between the sending of a message from one machine to another. (even if the process only takes a few milliseconds, slowdowns can be very apparent over transaction requiring many network packets to be transacted between client and server).

NetChannel allows you to configure following parameters for Latency:

Delay Type

There are following delay types:

Fixed delay (fixed-time)

All network data packets from source to destination takes constant amount of time. For example, if use ‘Fixed Delay’ of 100ms, then all packets will be delayed by 100ms. This can be verified using a simple ping test to host on the local network and it will show the delay of 100ms. If delay is configured in both directions, source to destination and destination to source, ping time will be the sum of both delays.

Random Mean delay

NetChannel allows you to configure the Delay type as Random. For random mean delay, you need to specify delay time and variation time. Actual delay will be a random delay with mean delay +/- variation. Also you can select any one of two type of delay:

  • Purely random delay: All delay times are purely random. Each delay sample is independent.
  • Co-related random delay: Each delay sample is co-related to previous delays. In real world, noise is known to happen in burst that can be best explained by co-related randomness.

Example: Random Delay with mean 100ms ± 10ms variation with 25% co-relation will cause all packets to delayed by a random time between 90-110ms with the current delay to be 25% dependent on the previous delay.

You can also specify one of following randomness distribution.

  • Uniform Random Distribution
  • Normal Distribution (bell curve)
  • Pareto Distribution
  • Pareto Normal Distribution

Packet Loss

NetChannel allows you to configure the Packet loss in the network. Packet loss is used to simulate an error condition in which data packets appear to be transmitted correctly at one end of a connection, but never arrive at the other. The smallest possible non-zero value is 0.00001%

  • Fixed packet loss: The number of packet loss is always Fixed percentage of packets is lost in every transaction. NetChannel allows you to configure the packet loss in percentage.
  • Co-related random packet loss: In this case, the number of packet loss is not fixed. NetChannel also allows you to configure the packet loss with co-relation value in percentage. Higher the co-relation, more will be the burstiness of packet loss.

Packet Duplication

The duplication of a data packet is handled by introducing unique identifiers. The sender tags each data packet with a unique identifier. The recipient records the identifiers of the data packets and discards packets whose identifiers have already been recorded.

Note that when the duplicate of a data packet occurs due to the loss of an acknowledgement packet, the acknowledgement packet has to be sent even when the data packet is discarded; otherwise the sender would keep resending the data packet.

NetChannel allows you to configure the Packet Duplication in Network with or without correlation.

Packet Re-Ordering

Packet reordering occurs when the order of packets at the destination is different than the order of the same packets at the source. In other words, in a non-reordered packet stream, the packet sequence number of any arriving packet will be lower than the sequence number of the consecutive arriving packet.

The following example shows a situation with reordered packets; the reordered sequences are underlined.

Using NetChannel, you can configure of re-ordering of packets in Network in percentage. If you use delay of 10ms and re-ordering of 20%, then every 5th (10th, 15th…) packet will be sent immediately and every other packet will be delayed by 10ms.

Using NetChannel

  • Define Tunnels by specifying Tunnel end-point.
  • Define network characteristics for Tunnels.
  • Tunnel impairments may be enabled or disabled.
  • Can be configured using command line or web based GUI.

NetChannel can be used in two modes:

Bridge mode

  • Need multiple network ports on NetChannel.
  • All communicating system communicates through NetChannel (tunnel end points) connected to a port NetChannel.
  • No need to change routing entries on tunnel end- point systems.

Router mode

Only one network port of NetChannel connected to the network.

Requires setting for routing entry

  • Need only one-network ports on NetChannel.
  • No change to all tunnel end-point systems network connections.
  • Need to add a routing entry on tunnel end point systems.