23
PTP options:
Option name
Value type/possible values
Description
PTP
Disabled/Grandmaster/Slave
Enabled PTP as Master/Slave.
PTP Options
Domain
number
Number [0...255]
A domain does define the scope of PTP message
communication, state, operations, data sets, and timescale.
Devices synchronize only to PTP devices within same
domain. Multiple domains mayy be used in signle
network.
Profile
IEEE1588/802.1AS
Defines whether synchronization is performed using
standard PTP (
IEEE1588
) or gPTP (
802.1AS
).
Transport layer L2/L4
L2 (Ethernet)
: PTP packets are encapsulated directly in
Ethernet frames (IEEE 802.3 network transport)
L4 (UDP)
: PTP packets are exchanged over UDP/IPv4
IP mode
multicast/unicast/hybrid
Delay
mechanism
E2E/P2P
E2E:
Delay is measured end-to-end. Delay is calculated
for the whole path
P2P:
Delay is measured peer-to-peer. If transparent clocks
are present in a network, they need to support peer-delay
mechanism (and have it enabled)
gPTP Slave
type
Slave-only/Master-capable
Defines whether gPTP Slave device may become a Master
in the network in case there is no other available. Cannot
become Grandmaster.
PTP Master configuration
Priority1
Number [0...255]
The attribute priority1 is used in the execution of the best
master clock algorithm. Lower values take precedence.
This is primarily checked field in best master clock
algorithm.
Priority2
Number [0...255]
The attribute priority2 is used in the execution of the best
master clock algorithm. Lower values take precedence.
This field is after clock class, accuracy and variance.
Sync interval
Number (log2) [-7...7]
(recommended [-3...3])
Interval for PTP Sync messages to be sent.
Unit used is log2 (logarithm 2), e.g.
-4: 62.5ms (1/16 s)
-3: 125ms (1/8 s)
-2: 250ms (1/4 s)
-1: 0.5s (1/2 s)
0: 1 second (typical interval)
1: 2 seconds (default)
2: 4 seconds
3: 8 seconds
4: 16 seconds
NOTE:
Editing this and following attributes must be done
with caution.
Announce
interval
Number (log2)
Interval for PTP Announce messages to be sent.
Min Delay
Request
Interval
Number (log2)
Interval for PTP Delay_Request messages to be sent to
host.
Min pDelay
Request
Interval
Number (log2)
Interval for PTP Peer_Delay_Request messages to be sent
to host.
