PTP - Precision Time Protocol

What is PTP?

The PTP (Precision Time Protocol) is a protocol used to synchronize clocks across a computer network with sub-microsecond accuracy.

What standard defines PTP?

PTP is defined by the IEEE 1588 standard. The first version, IEEE 1588-2002, is known as PTP v1.

What is the main use of PTP?

PTP is used in precise time coordination systems, such as industrial automation, telecommunications, power systems, and financial trading.

How does PTP achieve high accuracy?

PTP uses hardware timestamping and a master-slave hierarchy to minimize jitter and delay, achieving sub-microsecond synchronization.

What is the difference between PTP and NTP?

• PTP offers much higher precision (sub-microsecond) compared to NTP (millisecond-level), making it suitable for time-critical applications.

What is a PTP master-slave?

• The master clock provides the reference time, while slave clocks synchronize to it. This hierarchy ensures consistent time distribution.

Does PTP require special hardware?

For high accuracy, PTP benefits from hardware timestamping support in network interface cards (NICs) and switches.

What transport protocols does PTP use?

PTP typically uses UDP over IP networks, often on port 319 (event messages) and 320 (general messages).

Can PTP work over wireless communication?

While possible, wireless introduces variable latency and jitter, which can reduce synchronization accuracy.

What are the limitations of PTP v1?

PTP v1 lacks some features of later versions like profile support, improved fault tolerance, and better scalability.

Topics in this section,

• Learnings in this section

• Terminology

• Version Info

• PTP Version&RFC Details

• PTP Basic Setup on Ubuntu using IPv4

• PTP Basic Setup on Ubuntu using IPv6

• PTP Protocol Packet Details

• PTP Usecases

• PTP Basic Features

• PTP Feature : High Precision Time Sync

• PTP Feature : Master-Slave Architecture

• PTP Feature : Hardware Timestamping

• PTP Feature : Event and General Messages

• PTP Feature : Loopback Testing Support

• PTP Feature : Delay Measurement and Mechanism

• PTP Feature : Best Master Clock Algorithm

• PTP Feature : Multicast and Unicast Support

• PTP Feature : Profile-Based Configuration

• PTP Feature : Scalability

• Reference links

Learnings in this section

• In this section, you are going to learn

Terminology

• Terminology

Version Info

• Version Info

PTP Version&RFC Details

S.No	PTP Version	RFC / Standard	Core Idea / Contribution	Year
1	PTP v1	IEEE 1588-2002	Original version of PTP; introduced high-precision time sync using master-slave architecture.	2002
2	PTP v2	IEEE 1588-2008	Added support for profiles, improved accuracy, and new message types (Announce, Signaling).	2008
3	PTP v2.1	IEEE 1588-2019	Enhanced security, management, and terminology; backward-compatible with PTP v2.	2019
4	PTP MIB Support	RFC 8173	Defines SNMP MIBs for managing PTP devices.	2017
5	PTP over MPLS	RFC 8878	Describes transport of PTP messages over MPLS pseudowires.	2021
6	PTP YANG Models	RFC 8575	Specifies YANG data models for managing PTP clocks and devices.	2019
7	PTP Profile Use	RFC 7384	Guidelines for selecting and using PTP profiles in telecom networks.	2015
8	PTP in RTP	RFC 7273	Defines RTP Clock Source Signaling for PTP-based synchronization in media streams.	2014
9	Enterprise PTP	RFC 9760	Enterprise profile for PTP using IEEE 1588-2019; supports mixed multicast/unicast.	2025

PTP Basic Setup on Ubuntu using IPv4

• Setup

PTP Basic Setup on Ubuntu using IPv6

• Setup

PTP Protocol Packet Details

Syn Message Packet

S.No	Protocol Packet	Description	Size(Bytes)
1	Sync Message	Sent by the master clock to initiate synchronization with slave clocks.	4464
	Transport Header	UDP/IP header	28 (IPv4 + UDP)
	PTP Header	Common PTP message header	34
	Origin Timestamp	Time when Sync message was sent	10

Follow_up Message Packet

S.No	Protocol Packet	Description	Size(Bytes)
2	Follow_Up Message	Sent by the master clock to provide precise timestamp of the Sync message.	4464
	Transport Header	UDP/IP header	28
	PTP Header	Common PTP message header	34
	Precise Origin Timestamp	Accurate timestamp of the Sync message	10

Delay_Req Message Packet

S.No	Protocol Packet	Description	Size(Bytes)
3	Delay_Req Message	Sent by the slave clock to measure delay to the master.	4464
	Transport Header	UDP/IP header	28
	PTP Header	Common PTP message header	34
	Origin Timestamp	Time when Delay_Req was sent	10

Delay_Resp Packet

S.No	Protocol Packet	Description	Size(Bytes)
4	Delay_Resp Message	Sent by the master clock in response to Delay_Req, includes timestamp.	4464
	Transport Header	UDP/IP header	28
	PTP Header	Common PTP message header	34
	Receive Timestamp	Time when Delay_Req was received	10
	Requesting Port ID	Identifies the slave that sent Delay_Req	10

Management Message Packet

S.No	Protocol Packet	Description	Size(Bytes)
5	Management Message	Used for configuration, monitoring, and diagnostics of PTP devices.	48128+
	Transport Header	UDP/IP header	28
	PTP Header	Common PTP message header	34
	Management TLV	Type-Length-Value structure for management data	Variable (up to 64+)

Announce Message Packet

S.No	Protocol Packet	Description	Size(Bytes)
6	Announce Message	Introduced in PTP v2 (IEEE 1588-2008); used for Best Master Clock algorithm.	~81100
	Transport Header	UDP/IP header	28
	PTP Header	Common header for all PTP messages	34
	Current UTC Offset	Offset from TAI to UTC	2
	Grandmaster Priority 1	Priority value used in BMCA	1
	Clock Quality	Includes clock class, accuracy, and variance	4
	Grandmaster Priority 2	Secondary priority value	1
	Grandmaster Identity	Unique identifier of the grandmaster clock	8
	Steps Removed	Number of steps from grandmaster	2
	Time Source	Indicates source of time (e.g., GPS, atomic)	1

Signaling Message Packet

S.No	Protocol Packet	Description	Size(Bytes)
7	Signaling Message	Also introduced in PTP v2; used for optional features like unicast negotiation.	~72128+
	Transport Header	UDP/IP header	28
	PTP Header	Common header for all PTP messages	34
	Target Port Identity	Identifies the recipient of the signaling message	10
	TLV (Type-Length-Value)	Optional data block for negotiation or configuration	Variable (up to 64+)

PTP Usecases

S.No	Use Case	Description
1	Telecommunications	PTP is used to synchronize base stations in mobile networks (e.g., 4G/5G) to ensure seamless handovers and accurate time stamping for call/data sessions.
2	Power and Energy Systems	In smart grids and substations, PTP ensures precise time alignment for phasor measurement units (PMUs), fault detection, and event logging.
3	Financial Trading Systems	PTP provides sub-microsecond timestamping for trades, ensuring compliance with regulations like MiFID II and enabling accurate audit trails.
4	Industrial Automation	Used in factory automation and robotics to synchronize sensors, actuators, and controllers for real-time operations.
5	Broadcast and Media	PTP synchronizes audio/video equipment and cameras to maintain lip-sync and frame alignment in live production environments.
6	Aerospace and Defense	Ensures synchronized operations in radar systems, navigation, and mission-critical communication systems.
7	Data Centers and Cloud	PTP is used to synchronize distributed systems and logs across servers for consistency, debugging, and security auditing.
8	Railway and Transportation	Enables synchronized signaling, control systems, and event logging for safety and efficiency.
9	Scientific Research	Used in particle accelerators, telescopes, and observatories where precise timing is critical for data correlation.
10	Healthcare and Medical Devices	Synchronizes imaging systems and patient monitoring equipment for accurate diagnostics and data logging.

PTP Basic Features

S.No	Feature	Description
1	High Precision Time Sync	Provides sub-microsecond synchronization accuracy across networked devices.
2	Master-Slave Architecture	Uses a hierarchical model where slave clocks sync to a master clock.
3	Hardware Timestamping	Enables precise time capture at the physical layer, reducing jitter and delay.
4	Event and General Messages	Separates time-critical (event) and control (general) messages for efficiency.
5	Loopback Testing Support	Allows internal testing of timestamp accuracy and delay within a single device.
6	Delay Measurement Mechanism	Uses Delay_Req and Delay_Resp messages to calculate network delay.
7	Best Master Clock Algorithm	Automatically selects the most accurate clock in the network.
8	Multicast and Unicast Support	Supports both multicast (default) and unicast (optimized) communication modes.
9	Profile-Based Configuration	Allows customization for specific industries (e.g., telecom, power, AVB).
10	Scalability	Can be deployed in small LANs or large-scale industrial and telecom networks.

PTP Feature : High Presion Time Sync

High Precision Time Sync- Testcases

S.No	Test Case	Description	Expected Result
1	Basic Sync	Sync slave with master	Offset < 1s
2	Sync Interval	Test sync every 1s	Consistent updates
3	Delay Request Interval	Set delay request to 2s	Delay measured correctly
4	One-Step Clock	Use one-step clock mode	Accurate timestamps
5	Two-Step Clock	Use two-step clock mode	Accurate timestamps
6	Sync with GPS Master	Use GPS as master clock	High accuracy
7	Sync with Boundary Clock	Use boundary clock	Stable sync
8	Sync with Transparent Clock	Use transparent clock	Delay corrected
9	Clock Drift Compensation	Simulate drift	Drift corrected
10	Network Congestion	Introduce congestion	Sync remains accurate
11	Packet Loss	Drop 10% PTP packets	Sync maintained
12	Jitter Injection	Inject jitter	Offset within tolerance
13	Asymmetric Delay	Simulate asymmetric path	Delay compensated
14	Grandmaster Failover	Switch master	Seamless transition
15	Slave Clock Reset	Reset slave clock	Resyncs quickly
16	Master Clock Reset	Reset master clock	Slaves resync
17	Sync Accuracy Logging	Log sync accuracy	Offset < 1s
18	Sync Stability	Monitor over 24h	Stable offset
19	Sync with VLAN	Use VLAN tagging	Sync unaffected
20	Sync with QoS	Apply QoS to PTP	Prioritized packets
21	Sync with Encryption	Encrypt PTP packets	Sync still accurate
22	Sync with Authentication	Use PTP security	Authenticated sync
23	Sync with IPv6	Use IPv6 transport	Sync successful
24	Sync with Multicast	Use multicast mode	All slaves sync
25	Sync with Unicast	Use unicast mode	All slaves sync
26	Sync with Mixed Mode	Mix unicast/multicast	Sync maintained
27	Sync with Hardware Timestamping	Enable HW timestamp	High precision
28	Sync with Software Timestamping	Use SW timestamp	Lower precision
29	Sync with NTP Comparison	Compare with NTP	PTP more accurate
30	Sync with Leap Second	Simulate leap second	Handled correctly
31	Sync with Daylight Saving	DST change	No time jump
32	Sync with Time Zone Change	Change time zone	UTC unaffected
33	Sync with Multiple Slaves	100 slaves	All in sync
34	Sync with Multiple Masters	Multiple domains	Correct domain sync
35	Sync with Network Reboot	Reboot switch	Sync resumes
36	Sync with Slave Reboot	Reboot slave	Resyncs automatically
37	Sync with Master Reboot	Reboot master	Slaves resync
38	Sync with NIC Change	Change NIC	Sync continues
39	Sync with Interface Down	Bring interface down	Sync lost
40	Sync with Interface Up	Bring interface up	Sync resumes
41	Sync with Firewall	Enable firewall	PTP ports allowed
42	Sync with IDS/IPS	Enable IDS	No false positives
43	Sync with Logging Enabled	Enable logs	Events recorded
44	Sync with Monitoring Tool	Use PTP monitor	Accurate stats
45	Sync with SNMP	Query via SNMP	PTP data available
46	Sync with CLI	Use CLI tool	Shows sync status
47	Sync with GUI	Use GUI dashboard	Shows sync accuracy
48	Sync with API	Query via API	Offset and delay shown
49	Sync with Load Test	High CPU/network load	Sync stable
50	Sync with Time Drift Alert	Set alert threshold	Alert triggered on drift

PTP Feature : Master Slave Architecture

Master Slave Architecture - Testcases

S.No	Test Case	Description	Expected Result
1	Master Election	Elect best master clock	Highest priority clock selected
2	Slave Discovery	Slave detects master	Master identified
3	Announce Message Reception	Slave receives announce	Message processed
4	Sync Message Reception	Slave receives sync	Clock adjusted
5	Delay Request/Response	Slave sends delay request	Master responds correctly
6	BMCA Execution	Run Best Master Clock Algorithm	Correct master selected
7	Master Priority Change	Change master priority	New master elected
8	Slave Priority Change	Change slave priority	No master role assumed
9	Master Clock Failure	Simulate master failure	New master elected
10	Slave Clock Failure	Simulate slave failure	No impact on others
11	Master Clock Recovery	Recover failed master	Rejoins as slave
12	Slave Clock Recovery	Recover failed slave	Resyncs with master
13	Multiple Masters	Introduce multiple masters	Best one selected
14	Multiple Slaves	Add 100 slaves	All sync to master
15	Master Clock Drift	Simulate drift	Slaves adjust accordingly
16	Slave Clock Drift	Simulate drift	Corrected by sync
17	Master Clock Reboot	Reboot master	New master elected
18	Slave Clock Reboot	Reboot slave	Resyncs automatically
19	Master Clock Logging	Enable logs	Sync events logged
20	Slave Clock Logging	Enable logs	Sync events logged
21	Master Clock Monitoring	Monitor master	Status visible
22	Slave Clock Monitoring	Monitor slave	Status visible
23	Master Clock SNMP	Query via SNMP	Master data available
24	Slave Clock SNMP	Query via SNMP	Slave data available
25	Master Clock CLI	Use CLI tool	Shows master status
26	Slave Clock CLI	Use CLI tool	Shows slave status
27	Master Clock GUI	Use GUI dashboard	Master shown
28	Slave Clock GUI	Use GUI dashboard	Slave shown
29	Master Clock API	Query via API	Master info returned
30	Slave Clock API	Query via API	Slave info returned
31	Master Clock Authentication	Enable auth	Only trusted slaves sync
32	Slave Clock Authentication	Enable auth	Only trusted master accepted
33	Master Clock Encryption	Encrypt messages	Sync still accurate
34	Slave Clock Encryption	Decrypt messages	Sync successful
35	Master Clock VLAN	Use VLAN tagging	Sync unaffected
36	Slave Clock VLAN	Use VLAN tagging	Sync unaffected
37	Master Clock QoS	Apply QoS	PTP traffic prioritized
38	Slave Clock QoS	Apply QoS	PTP traffic prioritized
39	Master Clock with GPS	Use GPS as source	High accuracy
40	Slave Clock with GPS	Compare with GPS	PTP matches GPS
41	Master Clock with Boundary Clock	Use boundary clock	Sync relayed correctly
42	Slave Clock with Transparent Clock	Use transparent clock	Delay corrected
43	Master Clock in Multicast Mode	Use multicast	All slaves sync
44	Slave Clock in Unicast Mode	Use unicast	Sync successful
45	Master Clock in Hybrid Mode	Mix unicast/multicast	Sync maintained
46	Master Clock Load Test	High traffic load	Sync stable
47	Slave Clock Load Test	High CPU load	Sync stable
48	Master Clock Time Jump	Simulate time jump	Slaves adjust
49	Slave Clock Time Jump	Simulate time jump	Corrected by master
50	Master-Slave Role Reversal	Promote slave to master	New master functions correctly

PTP Feature : Hardware Timestamping

Hardware Timestamping - Testcases

S.No	Test Case	Description	Expected Result
1	Enable HW Timestamping	Enable on NIC	Timestamping enabled
2	Disable HW Timestamping	Disable on NIC	Timestamping disabled
3	HW Timestamp Accuracy	Compare with GPS	Accuracy < 100ns
4	HW vs SW Timestamp	Compare both	HW more accurate
5	HW Timestamp Drift	Monitor over time	Minimal drift
6	HW Timestamp Stability	Under load	Stable timestamps
7	HW Timestamp with Sync	Use in sync messages	Accurate sync
8	HW Timestamp with Delay Req	Use in delay request	Accurate delay calc
9	HW Timestamp with Delay Resp	Use in delay response	Accurate delay calc
10	HW Timestamp with Announce	Use in announce	Valid timestamp
11	HW Timestamp with One-Step Clock	Enable one-step	Accurate timestamp in sync
12	HW Timestamp with Two-Step Clock	Enable two-step	Accurate follow-up
13	HW Timestamp on Master	Enable on master	Accurate sync sent
14	HW Timestamp on Slave	Enable on slave	Accurate delay measured
15	HW Timestamp on Boundary Clock	Enable on BC	Accurate forwarding
16	HW Timestamp on Transparent Clock	Enable on TC	Accurate correction
17	HW Timestamp with VLAN	Use VLAN tagging	Timestamp unaffected
18	HW Timestamp with QoS	Apply QoS	Timestamp unaffected
19	HW Timestamp with IPv6	Use IPv6 transport	Timestamp valid
20	HW Timestamp with Multicast	Use multicast	Timestamp valid
21	HW Timestamp with Unicast	Use unicast	Timestamp valid
22	HW Timestamp with Encryption	Encrypt packets	Timestamp still valid
23	HW Timestamp with Authentication	Enable auth	Timestamp valid
24	HW Timestamp with NIC Reboot	Reboot NIC	Timestamping resumes
25	HW Timestamp with NIC Driver Reload	Reload driver	Timestamping resumes
26	HW Timestamp with NIC Change	Replace NIC	Timestamping supported
27	HW Timestamp with Firmware Update	Update firmware	Timestamping intact
28	HW Timestamp with OS Reboot	Reboot system	Timestamping resumes
29	HW Timestamp with High CPU Load	Stress CPU	Timestamping stable
30	HW Timestamp with High Network Load	Stress network	Timestamping stable
31	HW Timestamp with Packet Loss	Drop packets	Timestamping unaffected
32	HW Timestamp with Jitter	Inject jitter	Timestamping accurate
33	HW Timestamp with Delay	Inject delay	Timestamping accurate
34	HW Timestamp with Logging	Enable logs	Timestamps logged
35	HW Timestamp with Monitoring Tool	Use PTP monitor	HW timestamps visible
36	HW Timestamp with SNMP	Query via SNMP	Timestamp data available
37	HW Timestamp with CLI	Use CLI tool	Timestamping status shown
38	HW Timestamp with GUI	Use GUI dashboard	Timestamping status shown
39	HW Timestamp with API	Query via API	Timestamp data returned
40	HW Timestamp with Time Jump	Simulate time jump	Timestamping adjusts
41	HW Timestamp with Time Drift	Simulate drift	Timestamping compensates
42	HW Timestamp with Boundary Clock Failover	Fail BC	Timestamping continues
43	HW Timestamp with Transparent Clock Delay	Add delay	Correction field accurate
44	HW Timestamp with Multiple Interfaces	Enable on all	All interfaces timestamp
45	HW Timestamp with Multiple Domains	Use multiple PTP domains	Timestamping per domain
46	HW Timestamp with Sync Interval Change	Change interval	Timestamping adapts
47	HW Timestamp with Delay Interval Change	Change delay interval	Timestamping adapts
48	HW Timestamp with NIC Buffer Overflow	Overflow buffer	Timestamping stable
49	HW Timestamp with NIC Interrupt Storm	Simulate storm	Timestamping stable
50	HW Timestamp with External Time Source	Compare with GPS/IRIG	Timestamping matches

PTP Feature : Event and General Messages

Event and General Messages - Testcases

S.No	Test Case	Description	Expected Result
1	Sync Message Transmission	Master sends Sync	Sync sent with timestamp
2	Sync Message Reception	Slave receives Sync	Sync processed
3	Follow_Up Message Transmission	Master sends Follow_Up	Follow_Up sent with timestamp
4	Follow_Up Message Reception	Slave receives Follow_Up	Timestamp updated
5	Delay_Req Message Transmission	Slave sends Delay_Req	Message sent to master
6	Delay_Req Message Reception	Master receives Delay_Req	Timestamp recorded
7	Delay_Resp Message Transmission	Master sends Delay_Resp	Message sent to slave
8	Delay_Resp Message Reception	Slave receives Delay_Resp	Delay calculated
9	Announce Message Transmission	Master sends Announce	Message broadcasted
10	Announce Message Reception	Slave receives Announce	Master info updated
11	Management Message Transmission	Send management message	Message sent successfully
12	Management Message Reception	Receive management message	Message processed
13	Sync Message with HW Timestamp	Use hardware timestamp	Accurate timestamp recorded
14	Follow_Up with HW Timestamp	Use hardware timestamp	Accurate timestamp recorded
15	Delay_Req with HW Timestamp	Use hardware timestamp	Accurate timestamp recorded
16	Delay_Resp with HW Timestamp	Use hardware timestamp	Accurate timestamp recorded
17	Sync Message Loss	Drop Sync message	Slave waits for next
18	Follow_Up Message Loss	Drop Follow_Up	Slave ignores Sync
19	Delay_Req Message Loss	Drop Delay_Req	No Delay_Resp sent
20	Delay_Resp Message Loss	Drop Delay_Resp	Delay not updated
21	Announce Message Loss	Drop Announce	BMCA re-evaluated
22	Message Timestamp Validation	Check timestamp format	Valid timestamp
23	Message Interval Accuracy	Check message intervals	Matches configured interval
24	Message Sequence ID Check	Verify sequence IDs	IDs increment correctly
25	Message Domain Check	Use multiple domains	Messages isolated
26	Message Priority Check	Set different priorities	Higher priority wins
27	Message Authentication	Enable authentication	Only valid messages accepted
28	Message Encryption	Encrypt messages	Decrypted and processed
29	Message with VLAN Tag	Send over VLAN	Message received correctly
30	Message with QoS	Apply QoS	Prioritized delivery
31	Message with IPv6	Use IPv6 transport	Message delivered
32	Message with Multicast	Use multicast	All slaves receive
33	Message with Unicast	Use unicast	Targeted delivery
34	Message with Mixed Mode	Use both modes	All messages delivered
35	Message with Delay Variation	Inject delay	Delay compensated
36	Message with Jitter	Inject jitter	Sync remains stable
37	Message with Packet Duplication	Duplicate messages	Duplicates ignored
38	Message with Packet Reordering	Reorder messages	Correct order restored
39	Message with Packet Corruption	Corrupt message	Message discarded
40	Message Logging	Enable logging	Messages logged
41	Message Monitoring Tool	Use PTP monitor	Messages visible
42	Message SNMP Query	Query via SNMP	Message stats available
43	Message CLI Tool	Use CLI	Message counters shown
44	Message GUI Dashboard	Use GUI	Message flow visualized
45	Message API Access	Query via API	Message data returned
46	Message Load Test	High message rate	No loss or delay
47	Message Under CPU Load	High CPU usage	Messages processed
48	Message Under Network Load	High network usage	Messages delivered
49	Message with Time Jump	Simulate time jump	Messages adjust
50	Message with Clock Drift	Simulate drift	Messages correct offset

PTP Feature : Loopback Testing Support Algorithm

Loopback Testing Support Algorithm - Testcases

S.No	Test Case	Description	Expected Result
1	Enable Loopback Mode	Activate loopback on PTP interface	Loopback mode enabled
2	Disable Loopback Mode	Deactivate loopback	Loopback mode disabled
3	Loopback Sync Message	Send Sync in loopback	Message received internally
4	Loopback Follow_Up Message	Send Follow_Up in loopback	Message processed
5	Loopback Delay_Req Message	Send Delay_Req in loopback	Message received
6	Loopback Delay_Resp Message	Send Delay_Resp in loopback	Message processed
7	Loopback Announce Message	Send Announce in loopback	Message received
8	Loopback Management Message	Send management message	Message processed
9	Loopback Timestamp Accuracy	Measure timestamp accuracy	Offset < 100ns
10	Loopback Clock Sync	Perform full sync loopback	Clock adjusted correctly
11	Loopback with HW Timestamp	Enable hardware timestamp	Accurate timestamps
12	Loopback with SW Timestamp	Use software timestamp	Lower precision
13	Loopback Packet Loss Simulation	Drop packets in loopback	System handles loss
14	Loopback Jitter Simulation	Inject jitter	Sync remains stable
15	Loopback Delay Simulation	Inject delay	Delay compensated
16	Loopback Message Order	Reorder messages	Correct order restored
17	Loopback Message Duplication	Duplicate messages	Duplicates ignored
18	Loopback Message Corruption	Corrupt message	Message discarded
19	Loopback Message Logging	Enable logging	Messages logged
20	Loopback Message Monitoring	Use monitoring tool	Loopback traffic visible
21	Loopback Message SNMP	Query via SNMP	Loopback stats available
22	Loopback Message CLI	Use CLI tool	Loopback status shown
23	Loopback Message GUI	Use GUI dashboard	Loopback activity shown
24	Loopback Message API	Query via API	Loopback data returned
25	Loopback with Multicast	Use multicast in loopback	Message processed
26	Loopback with Unicast	Use unicast in loopback	Message processed
27	Loopback with VLAN	Use VLAN tagging	Message processed
28	Loopback with QoS	Apply QoS	Prioritized processing
29	Loopback with IPv6	Use IPv6 transport	Message processed
30	Loopback with Authentication	Enable auth	Message validated
31	Loopback with Encryption	Encrypt messages	Decrypted and processed
32	Loopback with Boundary Clock	Test BC in loopback	Sync relayed correctly
33	Loopback with Transparent Clock	Test TC in loopback	Delay corrected
34	Loopback with Time Jump	Simulate time jump	System adjusts
35	Loopback with Clock Drift	Simulate drift	Drift corrected
36	Loopback with High CPU Load	Stress CPU	Loopback stable
37	Loopback with High Network Load	Stress network	Loopback unaffected
38	Loopback with NIC Reboot	Reboot NIC	Loopback resumes
39	Loopback with NIC Driver Reload	Reload driver	Loopback resumes
40	Loopback with Interface Down	Bring interface down	Loopback fails
41	Loopback with Interface Up	Bring interface up	Loopback resumes
42	Loopback with Multiple Interfaces	Enable on all	Loopback works per interface
43	Loopback with Multiple Domains	Use multiple PTP domains	Loopback isolated
44	Loopback with Sync Interval Change	Change interval	Loopback adapts
45	Loopback with Delay Interval Change	Change delay interval	Loopback adapts
46	Loopback with Message Rate Limit	Limit message rate	Loopback respects limit
47	Loopback with Logging Level Change	Change log level	Logs reflect change
48	Loopback with Monitoring Interval	Change interval	Stats update accordingly
49	Loopback with Alert Threshold	Set alert on offset	Alert triggered
50	Loopback Test Completion	Run full loopback test	All checks pass

PTP Feature : Delay Measurement Mechanism

Delay Measurement Mechanism - Testcases

S.No	Test Case	Description	Expected Result
1	Basic Delay Measurement	Send Delay_Req and receive Delay_Resp	Delay calculated correctly
2	One-Step Clock Delay	Use one-step clock	Accurate delay with embedded timestamp
3	Two-Step Clock Delay	Use two-step clock	Accurate delay using Follow_Up
4	Hardware Timestamping	Use HW timestamps	High-precision delay
5	Software Timestamping	Use SW timestamps	Lower precision delay
6	Asymmetric Path Delay	Simulate asymmetric delay	Detected and compensated
7	Symmetric Path Delay	Equal delay both ways	Accurate delay
8	Delay with VLAN	Send over VLAN	Delay measured correctly
9	Delay with QoS	Apply QoS	Delay unaffected
10	Delay with IPv6	Use IPv6 transport	Delay measured
11	Delay with Multicast	Use multicast	Delay measured
12	Delay with Unicast	Use unicast	Delay measured
13	Delay with Transparent Clock	Use TC	Correction field applied
14	Delay with Boundary Clock	Use BC	Delay relayed correctly
15	Delay with Packet Loss	Drop Delay_Req	No Delay_Resp received
16	Delay with Packet Duplication	Duplicate Delay_Req	Only one Delay_Resp used
17	Delay with Packet Reordering	Reorder packets	Correct delay calculated
18	Delay with Packet Corruption	Corrupt Delay_Resp	Message discarded
19	Delay with Jitter	Inject jitter	Delay remains stable
20	Delay with Network Congestion	Simulate congestion	Delay increases, detected
21	Delay with Time Jump	Simulate time jump	Delay recalculated
22	Delay with Clock Drift	Simulate drift	Delay compensates
23	Delay with High CPU Load	Stress CPU	Delay measured accurately
24	Delay with High Network Load	Stress network	Delay measured accurately
25	Delay Interval Change	Change delay interval	Delay messages adapt
26	Delay with Logging Enabled	Enable logs	Delay events logged
27	Delay with Monitoring Tool	Use PTP monitor	Delay visible
28	Delay with SNMP	Query via SNMP	Delay stats available
29	Delay with CLI	Use CLI tool	Delay shown
30	Delay with GUI	Use GUI dashboard	Delay visualized
31	Delay with API	Query via API	Delay data returned
32	Delay with Authentication	Enable auth	Delay messages validated
33	Delay with Encryption	Encrypt messages	Delay calculated
34	Delay with Management Messages	Use mgmt interface	Delay stats queried
35	Delay with Multiple Slaves	100 slaves	All measure delay
36	Delay with Multiple Masters	Multiple domains	Delay per domain
37	Delay with NIC Reboot	Reboot NIC	Delay resumes
38	Delay with NIC Driver Reload	Reload driver	Delay resumes
39	Delay with Interface Down	Bring interface down	Delay fails
40	Delay with Interface Up	Bring interface up	Delay resumes
41	Delay with Loopback Mode	Use loopback	Delay = 0 or near-zero
42	Delay with GPS Master	Use GPS source	Delay accurate
43	Delay with External Time Source	Compare with IRIG/GPS	Delay matches
44	Delay with Alert Threshold	Set alert on delay	Alert triggered
45	Delay with Time Sync	Use delay in sync	Offset adjusted
46	Delay with Follow_Up Message	Use Follow_Up	Accurate delay
47	Delay with Announce Message	Use announce info	Delay context updated
48	Delay with Management Reset	Reset delay stats	Delay recalculated
49	Delay with Message Rate Limit	Limit delay messages	Delay still accurate
50	Delay with Test Harness	Use test tool	Delay validated

PTP Feature : Best Master CLock Algorithm

Best Master CLock Algorithm - Testcases

S.No	Test Case	Description	Expected Result
1	Single Master Available	Only one master present	Master selected
2	Multiple Masters, Different Priorities	Compare priority1 values	Lowest priority1 wins
3	Equal Priority1, Different Clock Class	Compare clockClass	Best class wins
4	Equal Clock Class, Different Accuracy	Compare clockAccuracy	Most accurate wins
5	Equal Accuracy, Different Offset Scaled Log Variance	Compare variance	Lowest wins
6	Equal Variance, Different Priority2	Compare priority2	Lowest wins
7	Equal All, Different Clock Identity	Compare clockIdentity	Lowest ID wins
8	Master Clock Failure	Master goes offline	New master elected
9	Master Clock Recovery	Failed master returns	Remains slave if not better
10	Slave Clock Becomes Better	Slave has better attributes	Becomes new master
11	Grandmaster Clock Change	New grandmaster joins	BMCA re-evaluates
12	Boundary Clock Participation	BC participates in BMCA	Best BC wins
13	Transparent Clock in Path	TC in path	BMCA unaffected
14	Announce Message Loss	Drop announce	BMCA waits for timeout
15	Announce Timeout	No announce received	BMCA triggers reelection
16	Announce Interval Change	Change interval	BMCA adapts
17	Domain Number Conflict	Same domain, different masters	BMCA resolves
18	Multiple Domains	Different domain numbers	BMCA runs per domain
19	Clock Identity Conflict	Duplicate clock IDs	BMCA fails or logs error
20	Clock Class Upgrade	Upgrade clock class	BMCA reselects master
21	Clock Accuracy Downgrade	Reduce accuracy	BMCA reselects master
22	Priority1 Change	Change priority1	BMCA re-evaluates
23	Priority2 Change	Change priority2	BMCA re-evaluates
24	Clock Quality Change	Change clock quality	BMCA re-evaluates
25	Clock Source Change	Switch to GPS	BMCA prefers GPS master
26	Clock Drift Simulation	Simulate drift	BMCA may reselect
27	Clock Jump Simulation	Simulate time jump	BMCA may reselect
28	BMCA with VLAN	Use VLAN tagging	BMCA functions normally
29	BMCA with QoS	Apply QoS	BMCA unaffected
30	BMCA with IPv6	Use IPv6 transport	BMCA functions normally
31	BMCA with Multicast	Use multicast	BMCA functions normally
32	BMCA with Unicast	Use unicast	BMCA functions normally
33	BMCA with Authentication	Enable auth	Only trusted clocks participate
34	BMCA with Encryption	Encrypt announce messages	BMCA functions securely
35	BMCA with Logging	Enable logs	BMCA decisions logged
36	BMCA with Monitoring Tool	Use PTP monitor	Master selection visible
37	BMCA with SNMP	Query via SNMP	BMCA status available
38	BMCA with CLI	Use CLI tool	Master info shown
39	BMCA with GUI	Use GUI dashboard	Master selection visualized
40	BMCA with API	Query via API	Master info returned
41	BMCA with High Network Load	Stress network	BMCA still functions
42	BMCA with High CPU Load	Stress CPU	BMCA still functions
43	BMCA with Clock Identity Change	Change clock ID	BMCA re-evaluates
44	BMCA with Clock Reset	Reset clock	BMCA re-evaluates
45	BMCA with Management Message	Query BMCA status	Correct info returned
46	BMCA with Multiple Interfaces	Multiple NICs	BMCA per interface
47	BMCA with Loopback Mode	Use loopback	BMCA runs locally
48	BMCA with Alert Threshold	Set alert on master change	Alert triggered
49	BMCA with Time Sync	Sync follows BMCA decision	Slaves sync to best master
50	BMCA with Test Harness	Use test tool	BMCA behavior validated

PTP Feature : Multicasr and Unicast Support

Multicast and Unicast Support - Testcases

S.No	Test Case	Description	Expected Result
1	Enable Multicast Mode	Configure PTP to use multicast	Multicast messages transmitted
2	Enable Unicast Mode	Configure PTP to use unicast	Unicast messages transmitted
3	Multicast Sync Message	Send Sync via multicast	All slaves receive
4	Unicast Sync Message	Send Sync via unicast	Target slave receives
5	Multicast Delay_Req	Slave sends Delay_Req via multicast	Master receives
6	Unicast Delay_Req	Slave sends Delay_Req via unicast	Master receives
7	Multicast Delay_Resp	Master sends Delay_Resp via multicast	All slaves receive
8	Unicast Delay_Resp	Master sends Delay_Resp via unicast	Target slave receives
9	Multicast Announce Message	Master sends Announce via multicast	All slaves receive
10	Unicast Announce Message	Master sends Announce via unicast	Target slave receives
11	Multicast Follow_Up Message	Master sends Follow_Up via multicast	All slaves receive
12	Unicast Follow_Up Message	Master sends Follow_Up via unicast	Target slave receives
13	Multicast Join Group	Slave joins multicast group	Group joined successfully
14	Multicast Leave Group	Slave leaves multicast group	Group left successfully
15	Unicast Negotiation	Slave requests unicast transmission	Master grants request
16	Multicast Packet Loss	Drop multicast packets	Slaves handle loss
17	Unicast Packet Loss	Drop unicast packets	Retransmission or timeout
18	Multicast Packet Duplication	Duplicate multicast packets	Duplicates ignored
19	Unicast Packet Duplication	Duplicate unicast packets	Duplicates ignored
20	Multicast Packet Reordering	Reorder multicast packets	Correct order restored
21	Unicast Packet Reordering	Reorder unicast packets	Correct order restored
22	Multicast with VLAN	Use VLAN tagging	Multicast works correctly
23	Unicast with VLAN	Use VLAN tagging	Unicast works correctly
24	Multicast with QoS	Apply QoS	Multicast prioritized
25	Unicast with QoS	Apply QoS	Unicast prioritized
26	Multicast with IPv6	Use IPv6 transport	Multicast works
27	Unicast with IPv6	Use IPv6 transport	Unicast works
28	Multicast with Authentication	Enable auth	Only valid messages accepted
29	Unicast with Authentication	Enable auth	Only valid messages accepted
30	Multicast with Encryption	Encrypt messages	Decrypted and processed
31	Unicast with Encryption	Encrypt messages	Decrypted and processed
32	Multicast with Boundary Clock	Use BC in multicast	Sync relayed correctly
33	Unicast with Boundary Clock	Use BC in unicast	Sync relayed correctly
34	Multicast with Transparent Clock	Use TC in multicast	Delay corrected
35	Unicast with Transparent Clock	Use TC in unicast	Delay corrected
36	Multicast with High Network Load	Stress network	Multicast stable
37	Unicast with High Network Load	Stress network	Unicast stable
38	Multicast with Monitoring Tool	Use PTP monitor	Multicast traffic visible
39	Unicast with Monitoring Tool	Use PTP monitor	Unicast traffic visible
40	Multicast with Logging	Enable logs	Multicast events logged
41	Unicast with Logging	Enable logs	Unicast events logged
42	Multicast with SNMP	Query via SNMP	Multicast stats available
43	Unicast with SNMP	Query via SNMP	Unicast stats available
44	Multicast with CLI	Use CLI tool	Multicast status shown
45	Unicast with CLI	Use CLI tool	Unicast status shown
46	Multicast with GUI	Use GUI dashboard	Multicast visualized
47	Unicast with GUI	Use GUI dashboard	Unicast visualized
48	Multicast with API	Query via API	Multicast data returned
49	Unicast with API	Query via API	Unicast data returned
50	Mixed Mode Operation	Use both multicast and unicast	Both modes function correctly

PTP Feature : Profile-Based Configuration

Profile-Based Configuration - Testcases

S.No	Test Case	Description	Expected Result
1	Load Default Profile	Load default PTP profile	Default profile parameters are applied
2	Load IEEE 1588-2008 Profile	Load IEEE 1588-2008 profile	IEEE 1588-2008 parameters are applied
3	Load Telecom Profile G.8275.1	Load Telecom Profile G.8275.1	G.8275.1 parameters are applied
4	Load Power Profile	Load Power Profile	Power profile parameters are applied
5	Load Custom Profile	Load custom user-defined profile	Custom parameters are applied correctly
6	Switch Profiles	Switch between profiles dynamically	System switches without error or time loss
7	Validate Profile Parameters	Validate profile parameter consistency	All parameters match profile specification
8	Invalid Profile Name	Apply invalid profile name	Error message is shown, no change applied
9	Missing Parameters	Apply profile with missing parameters	Error or fallback to default values
10	Save Profile	Save current configuration as a new profile	Profile saved and reusable
11	Delete Profile	Delete an existing profile	Profile removed from system
12	Delete Active Profile	Attempt to delete active profile	Operation blocked with warning
13	Profile Persistence	Profile persistence after reboot	Last used profile is retained
14	Apply via CLI	Apply profile via CLI	Profile applied successfully
15	Apply via GUI	Apply profile via GUI	Profile applied successfully
16	Apply via API	Apply profile via API	Profile applied successfully
17	Sync Interval	Validate sync interval from profile	Sync interval matches profile
18	Announce Interval	Validate announce interval from profile	Announce interval matches profile
19	Delay Mechanism	Validate delay mechanism from profile	Delay mechanism (E2E/P2P) is correct
20	Domain Number	Validate domain number from profile	Domain number is correctly set
21	Priority Values	Validate priority1 and priority2 values	Values match profile
22	Clock Class and Accuracy	Validate clockClass and clockAccuracy	Values match profile
23	Time Source	Validate timeSource field	Matches profile specification
24	Log Sync Interval	Validate logSyncInterval	Matches expected value
25	Log Announce Interval	Validate logAnnounceInterval	Matches expected value
26	Log Delay Req Interval	Validate logMinDelayReqInterval	Matches expected value
27	Boundary Clock	Validate profile on boundary clock	Boundary clock uses correct parameters
28	Transparent Clock	Validate profile on transparent clock	Transparent clock uses correct parameters
29	Ordinary Clock	Validate profile on ordinary clock	Ordinary clock uses correct parameters
30	Slave-Only Mode	Validate profile on slave-only device	Slave-only mode is enforced
31	Master-Only Mode	Validate profile on master-only device	Master-only mode is enforced
32	Hardware Timestamping	Validate profile with hardware timestamping	Hardware timestamping is enabled
33	Software Timestamping	Validate profile with software timestamping	Software timestamping is used
34	Multicast Transport	Validate profile with multicast transport	Multicast is used as per profile
35	Unicast Transport	Validate profile with unicast transport	Unicast is used as per profile
36	Hybrid Transport	Validate profile with hybrid transport	Hybrid transport is correctly configured
37	VLAN Tagging	Validate profile with VLAN tagging	VLAN settings are applied
38	QoS Settings	Validate profile with QoS settings	QoS settings match profile
39	Security Settings	Validate profile with security settings	Security parameters are enforced
40	BMCA Settings	Validate profile with BMCA settings	BMCA behavior matches profile
41	Alternate BMCA	Validate profile with alternate BMCA	Alternate BMCA is used if specified
42	Time Traceability	Validate profile with time traceability	Time traceability flags are correct
43	Leap Second Handling	Validate profile with leap second handling	Leap second behavior matches profile
44	UTC Offset	Validate profile with UTC offset	UTC offset is correctly applied
45	Time-of-Day Distribution	Validate profile with time-of-day distribution	ToD distribution is enabled
46	Holdover Settings	Validate profile with holdover settings	Holdover behavior matches profile
47	Servo Tuning	Validate profile with servo tuning parameters	Servo parameters are applied
48	Sync Packet Rate	Validate profile with sync packet rate	Sync packet rate matches profile
49	Announce Timeout	Validate profile with announce timeout	Timeout value is correct
50	Rollback on Failure	Validate profile rollback on failure	System reverts to last known good profile

PTP Feature : Scalability

Scalability - Testcases

S.No	Test Case	Description	Expected Result
1	10 Clients	Verify sync with 10 clients	All clients sync correctly
2	50 Clients	Verify sync with 50 clients	All clients sync correctly
3	100 Clients	Verify sync with 100 clients	All clients sync correctly
4	200 Clients	Verify sync with 200 clients	All clients sync correctly
5	500 Clients	Verify sync with 500 clients	All clients sync correctly
6	1000 Clients	Verify sync with 1000 clients	All clients sync correctly
7	10 Boundary Clocks	Test with 10 boundary clocks	All sync correctly
8	50 Boundary Clocks	Test with 50 boundary clocks	All sync correctly
9	100 Boundary Clocks	Test with 100 boundary clocks	All sync correctly
10	10 Transparent Clocks	Test with 10 transparent clocks	All function correctly
11	50 Transparent Clocks	Test with 50 transparent clocks	All function correctly
12	100 Transparent Clocks	Test with 100 transparent clocks	All function correctly
13	10 Master Clocks	Test with 10 master clocks	All function correctly
14	50 Master Clocks	Test with 50 master clocks	All function correctly
15	100 Master Clocks	Test with 100 master clocks	All function correctly
16	10 Slave Clocks	Test with 10 slave clocks	All sync correctly
17	50 Slave Clocks	Test with 50 slave clocks	All sync correctly
18	100 Slave Clocks	Test with 100 slave clocks	All sync correctly
19	10 Domains	Test sync across 10 domains	All domains sync independently
20	50 Domains	Test sync across 50 domains	All domains sync independently
21	100 Domains	Test sync across 100 domains	All domains sync independently
22	10 VLANs	Test sync across 10 VLANs	All VLANs sync correctly
23	50 VLANs	Test sync across 50 VLANs	All VLANs sync correctly
24	100 VLANs	Test sync across 100 VLANs	All VLANs sync correctly
25	Multicast Transport	Test scalability with multicast	All clients receive sync
26	Unicast Transport	Test scalability with unicast	All clients receive sync
27	Hybrid Transport	Test scalability with hybrid	All clients receive sync
28	High Sync Rate	Test with high sync rate	System maintains sync
29	Low Sync Rate	Test with low sync rate	System maintains sync
30	High Announce Rate	Test with high announce rate	System maintains sync
31	Low Announce Rate	Test with low announce rate	System maintains sync
32	High Delay Req Rate	Test with high delay req rate	System maintains sync
33	Low Delay Req Rate	Test with low delay req rate	System maintains sync
34	High Latency	Test under high network latency	System maintains sync
35	Packet Loss	Test under packet loss	System maintains sync
36	Jitter	Test under jitter	System maintains sync
37	Clock Drift	Test with clock drift	System compensates
38	Clock Offset	Test with clock offset	System compensates
39	Asymmetric Delay	Test with asymmetric delay	System compensates
40	Network Congestion	Test under congestion	System maintains sync
41	Redundant Masters	Test failover with backups	System switches to backup
42	Master Failure	Test behavior on master failure	System elects new master
43	Boundary Clock Failure	Test on boundary clock failure	Sync rerouted
44	Transparent Clock Failure	Test on transparent clock failure	Sync rerouted
45	Slave Clock Failure	Test on slave failure	Others unaffected
46	Dynamic Join	New clients join network	New clients sync correctly
47	Dynamic Leave	Clients leave network	Remaining clients unaffected
48	Topology Change	Network topology changes	System adapts and syncs
49	Time Source Change	Switch to new time source	System syncs to new source
50	Profile-Based Scaling	Test with different profiles	System scales per profile

Reference links

• Reference links