Network Simulator tool allows you to perform network bandwidth and delay simulation (simulate slow/congested links between nodes) on any connection from your computer to any remote node (on the local LAN or remote over Internet). The most useful feature of this utility is that you can install it on your workstation on which you are performing development or testing and create delay simulation profile such that delay would only apply to connections according to your filter criteria (source and destination IP addresses, source and destination ports and protocols).

How it works

The Network Simulator utility has driver component and user interface component. The driver component is installed to see all the network traffic passing between Network Interface Card (NIC) and TCP/IP stack.

When driver sees a packet it tries to match it against one of the configured flows. If packet doesn't match configured flow it is passed without delay to the NIC when sending or from the NIC to the TCP/IP when receiving. If packet matches one of the configured flows it will be added to corresponding simulation queue where all of the packets match the same flow criteria.

Periodically, according to simulated conditions (simulated delay, simulated bandwidth, simulated packet loss), packets are removed from the queue and passed to NIC when sending or to TCP/IP when receiving. When packet loss rate is configured (it is not implemented in current beta) packets are dropped as according to simulated packet loss rate.

The user interface component is used to perform creation of the flow and real time monitoring of stats for the created flow(s). Flows are only applied in the driver component when user interface component is running, when user interface component is closed all the flows are removed from the traffic.

Network Simulator has number of very useful features:

• Ability to simulate low network bandwidth, network delays and packet loss as if your traffic would be going over slow/congested network connections and all this is while you are connected to fast network connection. You can use it for application development and application testing, so you know how your application behaves when it is used over slow/congested network.
• Ability to create up to 32 simulation flows. Flow definition includes such things as: simulated bandwidth, simulated delay, simulated packet loss rate (not available in this beta version). Connections are matched to flows by checking match filter conditions, which include source and destination IP addresses, source and destination ports and protocol.
• Up to 32 network interface cards can be supported (assuming you have so many in installed in your system :-) )with each card having up to 32 simulation flow profiles at the same time.
• Ability to monitor in real time actual delay that is experienced by the traffic matching filter criteria, which is shows using real time graphs.
• Ability to monitor in real time statistics that includes such counters as queue depth, number of packets and bytes sent and received by all connections matching flow filter, packets lost. All counters have their current value, average value and standard deviation values.
• All other traffic, for example your usual traffic (e-mail, web browsing, file sharing etc.) that doesn't match simulation profile filters doesn't experience any delays and as result this utility can be used on your development or test PC workstation.
• Ability to save created simulation profile and share it with your coworker.

Download the latest vesrion of Network Simulator