NetDyn: Network
Measurements Tool
NetDyn is a low-overhead probing tool to measure network characteristics.
Download (.tar.gz)
It has four main processes:
- Source: It is the origin of probe packets. The source stamps
the probe packets with a Source Sequence Number (SSN) and a
Source TimeStamp (STS).
- Echo: It receives the packets from the Source and forwards
it to the Sink. It adds an Echo Sequence Number (ESN) and an
Echo TimeStamp (ETS).
- Sink: It receives the packet from the Echo process. It
adds a Sink TimeStamp (SiTS) and sends to the Logger process.
- Logger: It records the information of the different
timestamps and sequence numbers and discards the packets.
Using these five fields, it is possible to infer various characteristics
of the network path.
In the usual setting, the source, sink and logger are run in the same
machine, distinct from the machine in which the echo process executes
as shown in the figure.
The train of probe packets can be easily configured using this
tool including:
- Number of packets to send
- Burst size at each send instant
- Number of packets in the burst
- Inter and intra-burst packet gaps
- Protocol to use for packet delivery (TCP or UDP)
The tool compiles and executes for a lot of different platforms:
BSDs, SunOS/Solaris, Linux. It also has different scripts for
post-processing of the logged data, to infer various network
characteristics.
Please refer to the README file available in the distribution for
compilation and runtime instructions.
The code was originally written by Dheeraj Sanghi. I modified
and appended some parts of the code (including the TCP based
interaction).
| Last updated on July 2000 |
-- Suman
|