Tool

Description

• UDPmon

UDPmon is a network testing tool that uses UDP packets to make the following measurements between end hosts:

• Latency as a function of packet size - using Request-Response UDP packets.
• Histograms of the UDP Request-Response Latency.
• Estimation of the "on-the-wire" Bandwidth, packet loss, and out of order packets as a function of packet size and packet spacing using UDP packets.
• Histograms (and analysis) of the packet jitter between the two nodes.
• Measurement of arrival times of received packets
• Estimation of the relative 1-way delay between the two nodes on a packet by packet basis.
• Measurement of the user mode and kernel mode load on all CPUs for both sending and receiving hosts.
• Measurement of the number of interrupts given by the NICs
• Mesasurment of the number of packets seen by the interfaces and UDP/IP stack

The code, the write up and example command and Excel files for analysis and plotting are available.

• TCPmon

tcpmon uses Request-Response TCP messages and can make the following measurements of the round trip times between end hosts:

• The Round trip latency as a function of response size .
• Histograms of the TCP Request-Response latency
• A time series of the round trip latency for each Request-Response.

• dccpmon

dccpmon is a network testing tool that uses DCCP frames to make the following measurements between end hosts:

• ethmon

ethmon uses raw Ethernet frames to test the network performace between two end systems - similar functionality to UDPmon.

• TCPdelay

tcpdelay measures the arrival times of a series of message blocks sent as a continuous TCP/IP stream between two end hosts. By comparing the calculated time of arrival with the measured arrival time, the 1-way delay of each message block is estimated. The aim is to examine what happens to the arrival times when there is packet loss. (Experimental)

• disk_test

The disk_test programs read_file and write_file read or write blocks of data between memory and the RAID or disk sub-system, they measure:

• Data transfer rate between memory and the disk sub-system.
• Histograms of the individual read() or write() Latency.
• Measurement of the user mode and kernel mode load on all CPUs.
• Measurement of the number of interrupts

• mk5_test

read_sstor and write_sstor read or write blocks of data between memory and the VLBI Mark5 disk sub-system, they measure:

• Data transfer rate between memory and the disk sub-system.
• Histograms of the individual read() or write() Latency.
• Measurement of the user mode and kernel mode load on all CPUs.
• Measurement of the number of interrupts

• vlbi_udp

vlbi_send and vlbi_recv programs use UDP packets to send VLBI data between pairs of end systems. These programs are controlled by the vlbi_control program and can make time-series measurements:

• Measurement of the Bandwidth used by the VLBI data.
• Estimation of the "on-the-wire" Bandwidth.
• Measurement of the packet loss, and out of order packets.
• Estimation of the relative 1-way delay between the two nodes.

• mem_bw

Memory Bandwidth test program - quite dependant on compiler sophistication! Uses the CPU to read or write areas of memory. The size and number of reads or writes can be set.