nuttcp

network performance measurement tool

TLDR

Start server

$ nuttcp -S

Test throughput to server

$ nuttcp [server_ip]

Test UDP throughput

$ nuttcp -u [server_ip]

Specify bandwidth limit

$ nuttcp -R [100M] [server_ip]

Test for specific duration

$ nuttcp -T [30] [server_ip]

Receiver mode (reverse direction test)

$ nuttcp -r [server_ip]

Use multiple parallel streams

$ nuttcp -N [4] [server_ip]

Test with interval reporting every second

$ nuttcp -i [1] [server_ip]

nuttcp is a network performance measurement tool. It measures TCP and UDP throughput between systems, providing detailed statistics about network performance.nuttcp is similar to iperf but includes features such as server mode, rate limiting, multiple parallel streams, and timer-based usage. It also supports IPv6, IPv4 multicast, and setting TOS/DSCP bits.

PARAMETERS

-S

Server mode.

-u

UDP mode (default TCP).

-R rate

Rate limit (K, M, G).

-T time

Test duration.

-t

Transmitter mode.

-r

Receiver mode.

-p port

Data port.

-P port

Control port.

-w size

Window size (socket buffer size).

-N nstream

Number of parallel data streams (default 1, max 128).

-i interval

Interval reporting in seconds.

-l buflen

Length of network read/write buffer in bytes.

-s

Use stdin/stdout for data (enables disk-to-network transfers).

-F

Flip direction of data connection open (useful with firewalls/NAT).

-b

Brief one-line output (default format).

EXAMPLE OUTPUT

$ 84.8594 MB / 10.00 sec = 71.1477 Mbps 0 retrans

CAVEATS

Requires server on remote end. Firewall must allow ports. UDP tests may show packet loss. Results affected by other traffic.

HISTORY

nuttcp was developed by Bill Fink at NLANR/DAST as a network testing tool, building on the earlier ttcp.