G.8265.1 Profile

Information about G.8265.1 Profile

G.8265.1 profile fulfills specific frequency-distribution requirements in telecom networks. Features of G.8265.1 profile are:

  • Clock Advertisement: G.8265.1 specifies changes to values used in Announce messages for advertising PTP clocks: the clock class value is used to advertise the QL of the clock, while other values are not used.

  • Clock Selection: G.8265.1 profile also defines an alternate Best Master Clock Algorithm (BMCA) to select port states and clocks is defined for the profile. This profile also requires to receive Sync messages (and optionally, Delay-Response messages) to qualify a clock for selection.

  • Port State Decision: The ports are statically configured to be Master or Slave instead of using FSM to dynamically set port states.

  • Packet Rates: The packet rates higher than rates specified in the IEEE 1588-2008 standard are used. They are:

    • Sync/Follow-Up Packets: Rates from 128 packets-per-second to 16 seconds-per-packet.

    • Delay-Req/Delay-Resp Packets: Rates from 128 packets-per-second to 16 seconds-per-packet.

    • Announce Packets: Rates from 8 packets-per-second to 64 seconds-per-packet.

  • Transport Mechanism: G.8265.1 restricts the PTP transport mechanism to IPv4. G.8265.1 mandates that all packets should be sent unicast, rather than multicast.

  • Clock Type: G.8265.1 restricts the supported clock-types to Ordinary Clock (a clock with only a single PTP port). For a G.8265.1 slave, this means that all PTP ports on a single device operate independently of each other: functions such as clock selection operate outside of the context of each Ordinary Clock within the system.

  • Domain Numbers: G.8265.1 restricts the range of domain numbers to between 4 and 23, with the default being 4.

  • Port Numbers: G.8265.1 dictates that all port numbers for PTP ports should be 1, as all clocks within a G.8265.1 network are ordinary clocks.

    G.8265.1 also restricts the clock types in a network to Master and Slave clocks, meaning that neither boundary clock nor transparent clocks are supported. This document covers extensions to G.8265.1 in order to support boundary clock.

Limitations

  • G.8265.1 doesn’t support on sub-interface.

  • G.8265.1 doesn’t support on vrf interface.

  • G.8265.1 doesn’t support on port-channel interfac.

G.8265.1 Profile Mapping

The following table provides the mapping of SSM/ESMC and G.8265.1 QL values.

Table 1. G.8265.1 Profile Mapping

SSM QL

ITU-T G.781

Clock Class
Option I Option II Option III
0001 QL-PRS 80
0000 QL-STU QL-UNK 82
0010 QL-PRC 84
0111 QL-ST2 86
0011 88
0100 QL-SSU-A QL-TNC 90
0101 92
0110 94
1000 QL-SSU-B 96
1001 98
1101 QL-ST3E 100
1010 QL-ST3/QL-EEC2 102
1011 QL-SEC/QL-EEC1 QL-SEC 104
1100 QL-SMC 106
1110 QL-PROV 108
1111 QL-DUS 110

Configuring G.8265.1 Server and Client Ordinary Clock

Configuring Server Ordinary Clock

Follow these steps to configure server ordinary clock:

SUMMARY STEPS

  1. enable
  2. configure terminal
  3. ptp clock ordinary domain domain-number profile g8265.1
  4. priority1 priorityvalue
  5. priority2 priorityvalue
  6. clock-port port-name master
  7. transport ipv4 unicast interface interface-type interface-number [negotiation ]
  8. sync interval interval
  9. announce interval interval
  10. end

DETAILED STEPS

  Command or Action Purpose

Step 1

enable

Example:

Router> enable

Enables privileged EXEC mode.

  • Enter your password if prompted.

Step 2

configure terminal

Example:

Router# configure terminal

Enter configuration mode.

Step 3

ptp clock ordinary domain domain-number profile g8265.1

Example:

Router(config)# ptp clock ordinary domain 4 profile g8265.1

Configures the PTP ordinary clock. The profile keyword configures the clock to use the G.8265.1 profile. Using a telecom profile requires that the clock have a domain number of 4–23.

Step 4

priority1 priorityvalue

Example:

Router(config-ptp-clk)# priority1 priorityvalue

Sets the preference level for a clock. Client devices use the priority1 value when selecting a server clock: a lower priority1 value indicates a preferred clock. The priority1 value is considered above all other clock attributes.

Valid values are from 0-255. The default value is 128.

Step 5

priority2 priorityvalue

Example:

Router(config-ptp-clk)# priority1 priorityvalue

Sets a secondary preference level for a clock. Subordinaate devices use the priority2 value when selecting a server clock: a lower priority2 value indicates a preferred clock. The priority2 value is considered only when the router is unable to use priority1 and other clock attributes to select a clock.

Valid values are from 0-255. The default value is 128.

Step 6

clock-port port-name master

Example:

Router(config-ptp-clk)# clock-port master master

Sets the clock port to PTP server mode.

Step 7

transport ipv4 unicast interface interface-type interface-number [negotiation ]

Example:

Router(config-ptp-port)# transport ipv4 unicast interface GigabitEthernet 0/0/0 negotiation

Specifies the transport mechanism for clocking traffic. Loopback interface can be used as well as the WAN ports.

The client router IP address should be reachable via WAN interface (GigabitEthernet 0/0/0 or GigabitEthernet 0/0/1) so that PTP packets can be sent or received on the WAN ports.

The negotiation keyword configures the router to discover a PTP server clock from all available PTP clock sources.

Step 8

sync interval interval

Example:

Router(config-ptp-port)# sync interval -4

Specifies the interval used to send PTP synchronization messages. The intervals are set using log base 2 values, as follows:

  • 1—1 packet every 2 seconds

  • 0—1 packet every second

  • -1—1 packet every 1/2 second, or 2 packets per second

  • -2—1 packet every 1/4 second, or 4 packets per second

  • -3—1 packet every 1/8 second, or 8 packets per second

  • -4—1 packet every 1/16 seconds, or 16 packets per second.

  • -5—1 packet every 1/32 seconds, or 32 packets per second.

  • -6—1 packet every 1/64 seconds, or 64 packets per second.

  • -7—1 packet every 1/128 seconds, or 128 packets per second.

Step 9

announce interval interval

Example:

Router(config-ptp-port)# announce interval 2

Specifies the interval for PTP announce messages. The intervals are set using log base 2 values, as follows:

  • 3—1 packet every 8 seconds

  • 2—1 packet every 4 seconds

  • 1—1 packet every 2 seconds

  • 0—1 packet every second

  • -1—1 packet every 1/2 second, or 2 packets per second

  • -2—1 packet every 1/4 second, or 4 packets per second

  • -3—1 packet every 1/8 second, or 8 packets per second

Step 10

end

Example:

Router(config-ptp-port)# end

Exit configuration mode.

Configuring Client Ordinary Clock

Follow these steps to configure client ordinary clock:

SUMMARY STEPS

  1. enable
  2. configure terminal
  3. ptp clock ordinary domain domain-number profile g8265.1
  4. clock-port port-name slave
  5. transport ipv4 unicast interface interface-type interface-number [negotiation ]
  6. delay-req interval interval
  7. announce timeout value
  8. clock source source-address
  9. end

DETAILED STEPS

  Command or Action Purpose

Step 1

enable

Example:

Router> enable

Enables privileged EXEC mode.

  • Enter your password if prompted.

Step 2

configure terminal

Example:

Router# configure terminal

Enter configuration mode.

Step 3

ptp clock ordinary domain domain-number profile g8265.1

Example:

Router(config)# ptp clock ordinary domain 4 profile g8265.1

Configures the PTP ordinary clock. The profile keyword configures the clock to use the G.8265.1 profile. Using a telecom profile requires that the clock have a domain number of 4–23.

Step 4

clock-port port-name slave

Example:

Router(config-ptp-clk)# clock-port client slave

Sets the clock port to PTP client mode.

Step 5

transport ipv4 unicast interface interface-type interface-number [negotiation ]

Example:

Router(config-ptp-port)# transport ipv4 unicast interface GigabitEthernet 0/0/0 negotiation

Specifies the transport mechanism for clocking traffic. Loopback interface can be used as well as the WAN ports.

The server router IP address should be reachable via WAN interface (GigabitEthernet 0/0/0 or GigabitEthernet 0/0/1) so that PTP packets can be sent or received on the WAN ports.

The negotiation keyword configures the router to discover a PTP server clock from all available PTP clock sources.

Step 6

delay-req interval interval

Example:

Router(config-ptp-port)# delay-req interval -4

Configures the minimum interval allowed between PTP delay-request messages when the port is in the server state.

The intervals are set using log base 2 values, as follows:

  • 3—1 packet every 8 seconds

  • 2—1 packet every 4 seconds

  • 1—1 packet every 2 seconds

  • 0—1 packet every second

  • -1—1 packet every 1/2 second, or 2 packets per second

  • -2—1 packet every 1/4 second, or 4 packets per second

  • -3—1 packet every 1/8 second, or 8 packets per second

  • -4—1 packet every 1/16 seconds, or 16 packets per second.

  • -5—1 packet every 1/32 seconds, or 32 packets per second.

  • -6—1 packet every 1/64 seconds, or 64 packets per second.

  • -7—1 packet every 1/128 seconds, or 128 packets per second.

Step 7

announce timeout value

Example:

Router(config-ptp-port)# announce timeout 8

Specifies the number of PTP announcement intervals before the session times out. Valid values are 1-10.

Step 8

clock source source-address

Example:

Router(config-ptp-port)# clock-source 8.8.8.1

Specifies the address of a PTP server clock.

Step 9

end

Example:

Router(config-ptp-port)# end

Exit configuration mode.

Verifying the Configuration

You can use the following commands to verify a clocking configuration:

  • show ptp clock running domain <domain no>

  • show ptp clock dataset default

  • show ptp clock dataset parent

  • show ptp port <name of virtual port>

  • show ptp wan stat stream < stream id>

  • show network-clock synchronization

  • show ptp port dataset port

  • show ptp wan tod

  • show gnss time

  • show gnss status

Examples

IR8340#show ptp clock running domain 4
                      PTP Ordinary Clock [Domain 4]  [Profile: g8265.1]
         State          Ports          Pkts sent      Pkts rcvd      Redundancy Mode
         ACQUIRING      1              1543           4680           Hot standby
                               PORT SUMMARY
                                                                      PTP Master
Name  Tx Mode      Role         Transport    State        Sessions     Port Addr
slave unicast      slave        Gi0/0/1      Slave        1            2.3.1.1
                             SESSION INFORMATION
slave [Gi0/0/1] [Sessions 1]
 Peer addr          Pkts in    Pkts out   In Errs    Out Errs         
 2.3.1.1            4680       1543       0          0         
IR8340#

IR8340#show ptp clock running domain 4
                      PTP Ordinary Clock [Domain 4]  [Profile: g8265.1]
         State          Ports          Pkts sent      Pkts rcvd      Redundancy Mode
         PHASE_ALIGNED  1              44752          135639         Hot standby
                               PORT SUMMARY
                                                                       PTP Master
Name  Tx Mode      Role         Transport    State        Sessions     Port Addr
slave unicast      slave        Gi0/0/1      Slave        1            2.3.1.1
                             SESSION INFORMATION
slave [Gi0/0/1] [Sessions 1]
 Peer addr          Pkts in    Pkts out   In Errs    Out Errs  
 2.3.1.1            135639     44752      0          0         
IR8340#

IR8340#show ptp clock dataset default 
CLOCK [Ordinary Clock, domain 4]
  Profile: g8265.1
  Two Step Flag: No
  Clock Identity: 0x6C:03:09:FF:FE:18:5F:03
  Number Of Ports: 1
  Priority1: 128
  Priority2: 128
  Domain Number: 4
  Slave Only: Yes
  Clock Quality:
    Class: 255
    Accuracy: Unknown
    Offset (log variance): 0
IR8340#

IR8340#show ptp clock dataset parent 
CLOCK [Ordinary Clock, domain 4]
  Profile: g8265.1
  Parent Clock Identity: 0x44:B6:BE:FF:FE:42:EF:13
  Parent Port Number: 0
  Parent Stats: No
  Observed Parent Offset (log variance): 0
  Observed Parent Clock Phase Change Rate: 0
  Grandmaster Clock:
    Identity: 0x44:B6:BE:FF:FE:42:EF:13
    Priority1: 128
    Priority2: 128
    Clock Quality:
      Class: 104
      Accuracy: Unknown
      Offset (log variance): 52592
IR8340#

IR8340#show ptp clock dataset time-properties
CLOCK [Ordinary Clock, domain 4]

  Current UTC Offset Valid: FALSE
  Current UTC Offset: 37
  Leap 59: FALSE
  Leap 61: FALSE
  Time Traceable: FALSE
  Frequency Traceable: TRUE
  PTP Timescale: TRUE
  Time Source: Internal Oscillator
IR8340#

IR8340#show ptp port dataset port
PORT [slave]
  Clock Identity: 0x6C:03:09:FF:FE:18:5F:03
  Clock Profile: g8265.1
  Transport Interface: GigabitEthernet0/0/1
  Port Number: 1
  Port State: Slave
  Min Delay Req Interval (log base 2): -4
  Peer Mean Path Delay: 0
  Announce interval (log base 2): 1
  Announce Receipt Timeout: 3
  Sync Interval (log base 2): -5
  Delay Mechanism: End to End
  Peer Delay Request Interval (log base 2): -4
  PTP version: 2
IR8340#

IR8340#show ptp wan stat stream 0
LOCK STATUS : PHASE LOCKED
SYNC Packet Stats
  Time elapsed since last packet: 0.0
  Configured Interval : -5, Acting Interval -5
  Tx packets : 0,  Rx Packets : 96215
  Last Seq Number : 30678,  Error Packets : 0
Delay Req Packet Stats
  Time elapsed since last packet: 0.0
  Configured Interval : -4, Acting Interval : -4
  Tx packets : 48107, Rx Packets : 0
  Last Seq Number : 0, Error Packets : 0
Delay Response Packet Stats
  Time elapsed since last packet: 0.0
  Configured Interval : -4, Acting Interval : -4
  Tx packets : 0, Rx Packets : 48107
  Last Seq Number : 48106, Error Packets : 0
Announce Packet Stats
  Time elapsed since last packet: 0.0
  Configured Interval : 1, Acting Interval : 1
  Tx packets : 0, Rx Packets :  1509
  Last Seq Number 1508 Error Packets 0
Signalling Packet Stats
  Time elapsed since last packet: 0.0
  Configured Interval : 0, Acting Interval : 0
  Tx packets : 12, Rx Packets : 12
  Last Seq Number : 0, Error Packets : 0
Current Data Set                             Units     Within tolerance? 
  Offset from master :  +0.000000000        seconds          Yes
  Mean Path Delay    :  +0.000000027        seconds          Yes
  Forward Path Delay :  +0.000000027        seconds          Yes
  Reverse Path Delay :  +0.000000028        seconds          Yes
  Steps Removed 1
IR8340#

IR8340#show ptp wan tod
PTPd ToD information:

Time: 01/05/22 11:35:21

IR8340#