Ubuntu Manpage: isochron-rcv - Start an isochron test in the role of a receiver

NAME

       isochron-rcv - Start an isochron test in the role of a receiver

SYNOPSIS

       isochron rcv [OPTIONS]

DESCRIPTION

       This  command  starts a long-running process that listens for connections from an isochron
       sender, logs timestamps for the received test packets, and sends the logged data back.

OPTIONS

-h, --help
prints the short help message and exits

-i, --interface <IFNAME>
specify the network interface on which packets will be received

-d, --dmac <MACADDRESS>
specify the destination MAC address used by the application for recognizing test
packets. Can be either unicast or multicast. Necessary only for the L2 transport
(plain Ethernet). Optional, the interface’s unicast MAC address is used by
default.

-e, --etype <NUMBER>
specify the EtherType used by the application for recognizing test packets sent
using the L2 transport. Optional, defaults to 0xdead.

-P, --stats-port <NUMBER>
specify the TCP port on which the receiver program is listening for incoming
connections. This socket is used for management and statistics. Optional,
defaults to port 5000.

-s, --frame-size <NUMBER>
specify the size of test frames. The size is counted from the first octet of the
destination MAC address until the last octet of data before the FCS.

-S, --stats-address <NUMBER>
specify the IP address on which the receiver program is listening for incoming
connections. This socket is used for management and statistics. Supports binding
to a given network device using the address%device syntax (example: --stats-address
::%vrf0). Optional, defaults to ::, with a fallback to 0.0.0.0 if IPv6 is not
available.

-q, --quiet
this option suppresses error messages regarding invalid test packets. Optional,
defaults to false.

-f, --sched-fifo
when set, the program requests the kernel to change its scheduling policy to
SCHED_FIFO for the duration of the test.

-r, --sched-rr
when set, the program requests the kernel to change its scheduling policy to
SCHED_RR for the duration of the test.

-H, --sched-priority <NUMBER>
when either --sched-fifo or --sched-rr is used, the program requests the kernel to
change its scheduling priority for the duration of the test.

-O, --utc-tai-offset <NUMBER>
the program uses the CLOCK_TAI time base for its timers and for all reported
timestamps, and this option specifies the correction in seconds to apply to
software timestamps, which are taken by the kernel in the CLOCK_REALTIME (UTC) time
base. If this option is present, isochron will also change the kernel’s CLOCK_TAI
offset to the specified value, to ensure that its timers fire correctly. If the
option is absent, isochron queries the kernel’s CLOCK_TAI offset and attempts to
use that. If isochron can also query the UTC offset from ptp4l’s
TIME_PROPERTIES_DATA_SET using management messages, it does that and compares that
offset to the kernel’s UTC offset. The UTC offset reported by ptp4l has the
highest priority, and if the application detects that this is different from the
kernel’s CLOCK_TAI offset, it changes the kernel offset to the value queried from
ptp4l.

-2, --l2
this option specifies that the plain Ethernet transport should be used for the test
packets. Optional, defaults to true unless the sender overrides this via the
management socket.

-4, --l4
this option specifies that the UDP transport should be used for test packets.
Optional, defaults to false unless the sender overrides this via the management
socket.

-U, --unix-domain-socket <PATH>
isochron queries ptp4l’s state by creating and sending PTP management messages over
a local UNIX domain socket. This option specifies the path of this socket in the
filesystem. Optional, defaults to /var/run/ptp4l.

-N, --domain-number <NUMBER>
this option provides the domainNumber value to be used when constructing PTP
management messages sent to the ptp4l process. It must coincide with the
domainNumber used by ptp4l, otherwise it will not respond to management messages.
Optional, defaults to 0.

-t, --transport-specific <NUMBER>
this option provides the transportSpecific value to be used when constructing PTP
management messages sent to the ptp4l process. It must coincide with the
transportSpecific used by ptp4l, otherwise it will not respond to management
messages. Optional, defaults to 0. Note that PTP variants such as IEEE
802.1AS/gPTP require this value to be set to a different value such as 1.

-R, --num-readings <NUMBER>
isochron monitors the synchronization quality between the NIC’s PTP Hardware Clock
(PHC) and the system time by successively reading the system time, the PHC time and
the system time again, several times in a row, and picking the group of 3 time
readouts that took the least amount of time overall. This option specifies how
many readouts should be performed before picking the fastest one. Optional,
defaults to 5.

EXAMPLES

       To start an isochron receiver with PTP synchronization:

              ip link set eth0 up && ip addr add 192.168.100.2/24 dev eth0
              ptp4l -i eth0 -2 -P --step_threshold 0.00002 &
              phc2sys -a -rr --step_threshold 0.00002 &
              isochron rcv \
                  --interface eth0 \
                  --quiet \
                  --sched-rr \
                  --sched-priority 98

AUTHOR

       isochron was written by Vladimir Oltean <vladimir.oltean@nxp.com>

COMMENTS

       This man page was written using pandoc (http://pandoc.org/) by the same author.

                                                                                  isochron-rcv(8)