A mechanism in the Linux kernel for accessing information about a TCP socket. It has been supported since Linux 2.4.
The interface uses the
getsockopt() system call with the
TCP_INFO option on a TCP socket. The system will then fill in a caller-provided
struct tcp_info . The structure is defined in
ss program can be used with the
--info option to look at this information for active sockets.
This example shows a single active TCP socket, which represents the sending end of an ongoing Iperf TCP test:
(Note: In my tests, the send rate displayed by
ss was always about 50% lower than what
The socket on the receiving side looks like this:
Recent versions of iperf can use
TCP_INFO to extract detailed statistics from an ongoing TCP measurement.
- Measuring TCP Congestion Windows, René Pfeiffer, Linux Gazette, March 2007
– Main.SimonLeinen - 2014-12-26