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Configure PTP Multicast TimeTransmitter and TimeReceiver Ports for Ethernet Encapsulation

On an ACX Series router, you can configure a Precision Time Protocol (PTP) timeTransmitter boundary clock with IEEE 802.3 or Ethernet encapsulation of PTP messages to the timeReceiver clocks (ordinary and boundary) so that they can establish their relative time offset from this timeTransmitter's clock or clock reference. PTP over Ethernet uses multicast addresses for communication of PTP messages between the timeReceiver clock and the timeTransmitter clock. The timeReceiver clock automatically learns of timeTransmitter clocks in the network, is immediately able to receive the multicast messages from the timeTransmitter clock, and can begin sending messages to the timeTransmitter clock without any pre-provisioning. The timeTransmitter boundary clock synchronizes time through a timeReceiver boundary port.

To configure PTP over Ethernet with multicast timeTransmitter and timeReceiver ports, you must include the multicast-mode transport ieee-802.3 statement at the [edit protocols ptp master interface interface-name] and [edit protocols ptp slave interface interface-name] hierarchy levels, respectively.

To configure a PTP over Ethernet timeTransmitter boundary clock and timeReceiver boundary clock for multicast transmission, complete the following tasks:

Configure the PTP over Ethernet TimeTransmitter Boundary Clock Parameters

To configure the parameters of a PTP over Ethernet timeTransmitter boundary clock:

  1. Configure the clock mode.
  2. Configure the timeTransmitter clock.
  3. (Optional) Specify the log mean interval between announce messages—from 0 through 4. By default, one announce message is sent every two seconds. This configuration is used for manual timeReceiver clocks. The timeTransmitter boundary clock sends announce messages to manual timeReceiver clocks as specified in the announce-interval value.
  4. Configure the interface on which to respond to downstream PTP timeReceiver clocks or timeReceiver ports.

    For details about configuring the parameters for the timeTransmitter boundary clock interface, see Configure the PTP over Ethernet TimeTransmitter Boundary Clock Interface.

  5. (Optional) Specify the maximum log mean interval between announce messages—from 0 through 4. The default value is 4.
  6. (Optional) Specify the maximum log mean interval between delay-response messages—from –7 through 4. The default value is 4.
  7. (Optional) Specify the maximum log mean interval between synchronization messages—from –7 through 4. The default value is 4.
  8. (Optional) Specify the minimum log mean interval between announce messages—from 0 through 4. The default value is 0.
  9. (Optional) Specify the minimum log mean interval between delay-response messages—from –7 through 4. The default value is –7.
  10. (Optional) Specify the minimum log mean interval between synchronization messages—from –7 through 4. The default value is –7.
  11. (Optional) Specify the log mean interval between synchronization messages—from –7 through 4. The default value is –6. This configuration is used for manual timeReceiver clocks. The timeTransmitter boundary clock sends synchronization messages to manual timeReceiver clocks as specified in the syn-interval-value statement.

After you have configured the PTP timeTransmitter boundary clock parameters, enter the commit command from configuration mode. To complete the configuration of the timeTransmitter boundary clock, complete Configure the PTP over Ethernet TimeTransmitter Boundary Clock Interface.

Configure the PTP over Ethernet TimeTransmitter Boundary Clock Interface

After you configured the timeTransmitter boundary clock parameters for PTP over Ethernet with multicast transmission of PTP traffic, complete the configuration of the timeTransmitter boundary clock by configuring an interface to act in the role of the timeTransmitter clock.

To configure a PTP over Ethernet timeTransmitter boundary clock interface:

  1. Configure the interface on which to respond to downstream PTP timeReceiver ports or timeReceiver clocks.
    Note:

    For the configuration to work, the interface you specify must be configured at the [edit interfaces interface-name] hierarchy level.

  2. On this interface, configure multicast as the transmission mode of traffic for PTP timeReceiver clocks.
  3. Specify the encapsulation type for PTP packet transport as Ethernet or IEEE 802.3. This statement is mandatory.

    Alternatively, specify the encapsulation type as Ethernet with the link-local multicast address to be used in the sending of PTP messages. If you specify the link-local attribute, the timeTransmitter clock chooses either of the two MAC addresses defined in the IEEE 1588-2008 standard. When you configure this option, the system attempts to use the 01 -80-C2-00-00-0E MAC address (link-local multicast MAC address) for multicast transmission. If this MAC address is not available, the 01-1B-19-00-00-00 address (standard Ethernet multicast address) is used as the second priority. The standard Ethernet multicast address is used by default. You need to explicitly configure the link-local multicast address.

After you have configured the PTP over Ethernet timeTransmitter clock interface, enter the commit command from configuration mode.

Configure the PTP over Ethernet TimeReceiver Clock Parameters

An interface on which the timeTransmitter clock is configured is called a timeTransmitter interface and an interface on which the timeReceiver clock is configured is called a timeReceiver interface. A timeTransmitter interface functions as the timeTransmitter port and a timeReceiver interface functions as the timeReceiver port. Because PTP over Ethernet uses multicast addresses, a timeReceiver port can automatically start receiving the multicast announce messages transmitted by the timeTransmitter ports on a network and can also start communication with the timeTransmitter port with minimal or no configuration. You can optionally configure these settings for a timeReceiver port that communicates with the timeTransmitter ports using PTP over Ethernet.

To configure a PTP over Ethernet timeReceiver clock.

  1. Configure the clock mode:
  2. Configure the timeReceiver clock.
  3. (Optional) Specify the number of announce messages that a timeReceiver clock or port—configured on an ACX Series router—must miss before an announce timeout is declared—from 2 through 10. The default value is 3.
  4. (Optional) Specify the logarithmic mean interval in seconds between the delay request messages sent by the timeReceiver port to the timeTransmitter port—from –6 through 3. The default value is 0.
  5. Configure the interface for the timeReceiver clock.
  6. (Optional) Configure the log mean interval between synchronization messages—from –6 through -3. The default value is –6, which means by default, 64 synchronous interval messages sent per second.

After you have configured the PTP timeReceiver clock parameters, enter the commit command in configuration mode. To complete the configuration of the timeReceiver clock, complete Configure PTP over Ethernet TimeReceiver Clock Interface.

Configure PTP over Ethernet TimeReceiver Clock Interface

The timeReceiver clock interface responds to the upstream PTP timeTransmitter clock.

To configure the PTP timeReceiver clock interface:

  1. Configure the interface for the timeReceiver clock.
  2. Configure the upstream multicast PTP timeTransmitter clock source parameters.
  3. Specify the encapsulation type for PTP packet transport as Ethernet or IEEE 802.3. This statement is mandatory.

    Alternatively, specify the encapsulation type as Ethernet with the link-local multicast address to be used in the sending of PTP messages. If you specify the link-local attribute, the timeTransmitter clock chooses either of the two MAC addresses defined in the IEEE 1588-2008 standard. When you configure this option, the system attempts to use the 01 -80-C2-00-00-0E MAC address (link-local multicast MAC address) for multicast transmission. If this MAC address is not available, the 01-1B-19-00-00-00 address (standard Ethernet multicast address) is used as the second priority. The standard Ethernet multicast address is used by default. You need to explicitly configure the link-local multicast address.

After you have configured the PTP over Ethernet timeReceiver clock interface, enter the commit command in configuration mode.