ptp min-delayreq-interval

Function

The ptp min-delayreq-interval command sets the minimum interval at which a PTP interface sends Delay_Req packets.

The undo ptp min-delayreq-interval command restores the default minimum interval at which a PTP interface sends Delay_Req packets.

In G.8275.1 and CU-106 modes, the default value is 6. In other PTP modes, the default value is 7.

Format

ptp min-delayreq-interval min-delayreq-interval

undo ptp min-delayreq-interval

Parameters

Parameter	Description	Value
min-delayreq-interval	Specifies the minimum interval at which a PTP interface sends Delay_Req packets.	The value is an integer. The value range depends on the board type. The mappings between min-delayreq-interval and the actual sending interval are as follows: 0 1/1024s 1 2/1024s 2 4/1024s 3 8/1024s 4 16/1024s 5 32/1024s 6 64/1024s 7 128/1024s 8 256/1024s 9 512/1024s 10 1s 11 2s 12 4s 13 8s 14 16s 15 32s 16 64s 17 128s 18 256s 19 512s 20 1024s

Parameter

Description

Value

min-delayreq-interval

Specifies the minimum interval at which a PTP interface sends Delay_Req packets.

The value is an integer. The value range depends on the board type. The mappings between min-delayreq-interval and the actual sending interval are as follows:

0 1/1024s
1 2/1024s
2 4/1024s
3 8/1024s
4 16/1024s
5 32/1024s
6 64/1024s
7 128/1024s
8 256/1024s
9 512/1024s
10 1s
11 2s
12 4s
13 8s
14 16s
15 32s
16 64s
17 128s
18 256s
19 512s
20 1024s

Views

100GE interface view, 10G LAN interface view, 25GE interface view, 400GE interface view, 40GE interface view, 50GE interface view, FlexE-100G interface view, FlexE-400G interface view, FlexE-50G interface view, GE optical interface view, GE electrical interface view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
clksync	write

Usage Guidelines

Usage Scenario

Two devices exchange Announce packets to determine the master/slave relationship. The master device sends Sync packets to notify the slave device of time signal parameters and uses a delay measurement mechanism to achieve time signals accuracy.

Different delays on links deteriorate the accuracy of PTP time synchronization. PTP uses the delay measurement mechanism to correct time signals. A delay measurement process is implemented by sending delay measurement request packets and delay response packets. Either of the following parameters can be configured in the ptp delay-mechanism command to enable a specific delay measurement mechanism:

delay: enables the delay request-response mechanism, in which information about the clock and time is calculated based on the delay of an entire link between the master and slave clocks. Only the slave clock sends Delay_Req packets to the master clock, and the master clock replies with Delay_Resp packets. Upon receipt, the slave clock uses information carried in Delay_Resp packets to correct time signals.
pdelay: enables the peer delay mechanism, in which information about the clock and time is calculated based on the delay time of each link along the path between the master and slave clocks. In this mode, the master and slave clocks can send Pdelay_Rep packets to each other and then correct time signals based on the Pdelay_Resp packets. Upon receipt of the responses, the slave or master clock uses information carried in Delay_Resp packets to correct time signals.
If devices exchange PTP packets frequently and consume a lot of bandwidth resources, increase the min-delayreq-interval value. If time synchronization accuracy is low, reduce the min-delayreq-interval value.

Prerequisites

The delay request-response mechanism has been configured using the ptp delay-mechanism delay command on an OC interface, a BC interface, or a TCandBC interface.

Precautions

This command is supported only by the admin VS.

Example

# Set the interval at which GE 0/1/0 sends Delay_Req packets to 256/1024s.

<HUAWEI> system-view
[~HUAWEI] interface GigabitEthernet 0/1/0
[~HUAWEI-GigabitEthernet0/1/0] ptp min-delayreq-interval 8