PTP setup

PTP is required for sub-frame synchronization across cameras. Two setups are supported:

• Host-only, using linuxptp to sync NIC ports on a single host (cameras attached directly to a NIC).
• Switched, using a PTP-capable switch (Arista and Mellanox/Onyx examples below).

Host-only PTP

1. Install linuxptp

sudo apt install linuxptp

2. Set boundary clock

If you don't have a ptp4l.conf file, create /etc/ptp4l.conf:

[global]
verbose 1
boundary_clock_jbod 1

3. Synchronize NICs

If you only have one NIC card:

sudo ptp4l -i enp66s0f0np0 -i enp66s0f1np1 -f /etc/ptp4l.conf

This syncs the ports of the NIC. enp66s0f0np0 and enp66s0f1np1 are example port names — change them to your port names.

For multiple NICs, sync all ports across all NICs:

sudo ptp4l -i enp66s0f0np0 -i enp66s0f1np1 -i enp97s0f0np0 -i enp97s0f1np1 -f /etc/ptp4l.conf

In another terminal, run:

sudo phc2sys -a -rr -m

This syncs the computer time and treats it as a time source.

Switched PTP

If you're using a network switch, enable PTP on all the ports connected to either cameras or host NICs. Examples below for Arista and Mellanox (Onyx) switches.

Arista

Once logged in:

en
conf t
show ptp

If PTP is disabled:

ptp mode boundary

Configure each port:

show interface

Example: enable PTP on port 5

interface Ethernet 5
ptp enable

Multiple ports:

interface Ethernet49/1-Ethernet60/1
ptp enable

interface Ethernet1-Ethernet48
ptp enable

show int sta

If a port is in errdisabled, restart it:

interface Ethernet ##
shutdown
no shutdown

To disable spanning tree:

spanning-tree bpduguard disable

Mellanox (Onyx)

Reference: MLNX-OS Ethernet Command Reference Guide.

Useful commands:

show interface ethernet 1/11

enable
configure terminal
interface ethernet 1/11
shutdown
mtu 9216
speed 25000
fec rs-fec
no shutdown

To configure multiple ports:

interface ethernet 1/1-1/16 shutdown
interface ethernet 1/1-1/16 mtu 9216
interface ethernet 1/1-1/16 fec rs-fec
interface ethernet 1/1-1/16 speed 25G
interface ethernet 1/1-1/16 no shutdown