White Rabbit

Configuration

After configuring if White Rabbit is a Slave (Timing Source) or a Master port, the only configuration that might be realized is which Transport Protocol should be used.

By default, WR uses the data layer (RAW Ethernet packets - IEEE 802.3) to communicate to other WR devices but it can be configured to also use the UDP/IPv4 packets.

To configure Transport Protocol, log in to the Web GUI and navigate to Configuration > White Rabbit.

Configuration of WR instance.

Info/Overview

Active servo

When the device is running as a WR Boundary Clock, this means that one of the fiber network interfaces is an active slave. The data related to how the servo disciplines the internal oscillator can thus be visualized under the active servo panel.

OID Name Value Type Description
1.1220.x act/servo Information about the active servo instance
1.1220.1 Interface Name <String> Name of the network interface on which the servo is running.
1.1220.6 State 0. Disabled
1. Adjusting Time
2. Adjusting Time
3. Adjusting Phase
4. Locked
5. Wait Stable Phase
6. Invalid
7. Undefined
8. Not Updated
9. Wait Time Adjust
10. Wait Phase Adjust
11. Initializing 		Servo State: where ‘Locked’ corresponds to the legacy TRACK_PHASE state and means that the corresponding interface is actively disciplining the device. Disabled is used when the port is setup as Master or does not receive any valid PTP/WR exchange.
Note: The 1st state corresponds to adjustments in seconds order, and the 2nd one to adjustments in nanoseconds order.
1.1220.5 Up Count <Integer> (u32) Number of updates for the servo. It is typically increased by 1 each second.
1.1220.10 Mean Delay <Decimal> (f64)
Unit: s 		Cable round trip time excluding fixed+semistatic (cRTT).
1.1220.11 Delay MS <Decimal> (f64)
Unit: s 		Calculated Delay between Master and Slave considering asymmetry and fixed delays.
1.1220.21 Egress Latency <Decimal> (f64)
Unit: ns 		Fixed latency between the moment when a PTP packet is timestamped to its exit on the physical layer (i.e., optical fiber). Legacy: ’WR Slave ∆Tx’.
1.1220.20 Ingress Latency <Decimal> (f64)
Unit: ns 		Fixed latency between the moment when a PTP/WR packet ingresses from the physical layer to its timestamp. Legacy: ’WR Slave ∆Rx’.

Port Instance

A WR port instance is then associated to each network interface. The table displayed in the following image provides a quick overview of the state of each interface.

WR Interfaces overview (Only first interface captured (wr0)).

The parameters shown are explained in the following table:

OID Name Value Type Description
1.xx10.x net/wrX/1/ Information about WR for the wrX network interface. (Where OIDs follow the given pattern: wr0 → 20xx, wr1 → 21xx, ..., wr15 → 35xx)
1.xx10.5 Link Down
Up		 Specify if the link is up or down.
1.xx10.10 Port State 0. None
1. Initializing
2. Faulty
3. Disabled
4. Listening
5. Pre-Master
6. Master
7. Passive
8. Uncalibrated
9. Slave		 Current state of the port that changes according to the PTP protocol events.
• If this port is configured as a timing source, it can be Slave (active) or Passive (only handle announce messages)  Color: Blue.
• The port state is Disabled when the link is down or when the port has been configured with PTP instead of WR.
• The port state will be Master if it distributes WR timing (Color: Purple).
• Finally, the other states are transition states (mainly used by BMCA) or error states.
1.xx10.11 Clock State 0. Idle
1. Locking
2. Locked to REF 3. Holdover
4. Error
5. Free-Running 		State of the clock (internal oscillator) shared by all PTP instances. “Locked to Ref” is the desired stated.
1.xx10.20 Peer MAC <Data Array> (6 x u8) MAC address of the latest peer.
1.xx10.23 Peer VID <Integer> (u16) VLAN ID of the connected peer.
1.xx10.25 Peer N Tx PTP <Integer> (u32) Number of transmitted PTP packet on this port.
1.xx10.26 Peer N Rx PTP <Integer> (u32) Number of received PTP packet on this port.

If the interface is currently running WR (“Port State” not “Disabled”), the user can expand (+) a specific interface to display an Advanced Overview (See the figure below):

Advanced WR interface Overview (WR0 configured as slave)

Note: The clock information (clock quality & time properties) displayed in the expanded view above corresponds to the announced messages received on this specific interface and not the transmitted ones. This information is irrelevant (disabled) if the link is down or when the connected peer is not sending any announce messages (e.g., slave role).

The information shown in the advanced overview menu is explained in the following table:

OID Name Value Type Description
1.xx10.x net/<wrX>/1/ Information of the corresponding WR port instance (wrX). (Where OIDs follow the given pattern: wr0 → 20xx, wr1 → 21xx, ..., wr15 → 35xx)
1.xx10.6 PDet State 0. None
1. Waiting 1st Msg
2. Checking
3. Detected
4. Failure 		State of the Protocol Detection.
1.xx10.5 Ext State 0. Disabled
1. Active
2. PTP Only 		State of the extension. If PTP Only this means that the WR extension has not been detected.
1.xx10.5 Rx Sync ID <Integer> (u16) Receive Sync Sequence ID.
1.xx10.5 Peer VID <Integer> (u16) VLAN ID of the connected peer.
1.xx31.xx net/<wrX>/1/clk/Q/ Clock Quality of the corresponding WR port instance (wrX).
3.13x1.1 Clock Identity <Data Array> (8 x u8) Unique identity of PTP instance in the network.
1.xx31.2 Priority1 <Integer> Force BMCA decision using 1st priority (Lower values take precedence).
1.xx31.3 Priority2 <Integer> Used by BMCA to force selection between two clocks when their clock qualities are the same (Lower values take precedence).
1.xx31.10 Clock Class <Integer> The Clock Class is one of the attributes that characterizes the port instance.
1.xx31.11 Clock Accuracy <Enum> It indicates the expected accuracy of the timing source. It shall be conservatively estimated based on the time source.
1.xx31.12 Variance <Integer> (u16) Estimation of the variations of the Local PTP Clock as measured by comparison to a suitable reference clock.
1.xx31.20 N Hops <Integer> (u32) Number of PTP communication paths traversed between this PTP instance to the GrandMaster PTP Instance (aka stepsRemoved).
1.xx32.xx net/<wrX>/1/clk/tprop/ Time Properties of the corresponding WR port instance (wrX).
1.xx32.1 Time Source <Enum> This information-only attribute indicates the immediate source of time used by the Grandmaster.
1.xx32.12 UTC Offset Valid <Bool> True, if the current UTC offset is known to be valid (It will handle the next leap second jump).

Note: To obtain more details about time properties & clock quality of a given WR port instance, the user should use gpa_ctrl tool with the -a (expert) flag or with the –A (expert & disabled) flag.