- play_arrow Overview
- play_arrow Precision Time Protocol
- play_arrow Precision Time Protocol Overview
- play_arrow Precision Time Protocol Clocks
- PTP Boundary Clock Overview
- Example: Configure PTP Boundary Clock
- Example: Configure PTP Boundary Clock With Unicast Negotiation
- Configure PTP TimeTransmitter Clock
- Configure PTP TimeReceiver Clock
- Example: Configure Ordinary TimeReceiver Clock With Unicast-Negotiation
- Example: Configure Ordinary TimeReceiver Clock Without Unicast-Negotiation
- PTP Transparent Clocks
- Configure PTP Transparent Clock
- play_arrow Precision Time Protocol Profiles
- play_arrow PHY Timestamping
- play_arrow Precision Time Protocol over Ethernet
- PTP over Ethernet Overview
- Guidelines to Configure PTP over Ethernet
- Configure PTP Dynamic Ports for Ethernet Encapsulation
- Configure PTP Multicast TimeTransmitter and TimeReceiver Ports for Ethernet Encapsulation
- Example: Configure PTP over Ethernet for Multicast TimeTransmitter, TimeReceiver, and Dynamic Ports
- play_arrow Precision Time Protocol Additional Features
- Precision Time Protocol (PTP) over Link Aggregation Group (LAG)
- Precision Time Protocol (PTP) Trace Overview
- Line Card Redundancy for PTP
- Timing Defects and Event Management on Routing Platforms
- SNMP MIB for Timing on Routing Platforms
- PTP Passive Port Performance Monitoring on PTX10004 and PTX10008 Devices
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- play_arrow Global Navigation Satellite System (GNSS)
- play_arrow GPS Systems on Routing Platforms
- play_arrow Integrated GNSS on Routing Platforms
- play_arrow GNSS Configuration for Routers Using External GNSS Receiver
- play_arrow Assisted Partial Timing Support (APTS) on Routing Platforms
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- play_arrow Network Time Protocol
- play_arrow NTP Concepts
- play_arrow NTP Configuration Examples
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- play_arrow Synchronous Ethernet
- play_arrow Synchronous Ethernet Overview
- play_arrow Synchronous Ethernet on 10-Gigabit Ethernet MIC
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- play_arrow Hybrid Mode
- play_arrow Hybrid Mode Overview
- play_arrow Hybrid Mode and ESMC Quality-Level Mapping
- Configure Hybrid Mode and ESMC Quality-Level Mapping Overview
- Configure Hybrid Mode with Mapping of the PTP Clock Class to the ESMC Quality-Level
- Configure Hybrid Mode with a User-Defined Mapping of the PTP Clock Class to the ESMC Quality-Level
- Example: Configure Hybrid Mode and ESMC Quality-Level Mapping on ACX Series Router
- Example: Configure Hybrid Mode and ESMC Quality-Level Mapping on MX240 Router
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- play_arrow Configuration Statements and Operational Commands
- play_arrow Appendix
Clock Synchronization
Clock synchronization aims to coordinate otherwise independent clocks.
Clock Synchronization Overview
MX Series and PTX Series routers support external clock synchronization and automatic clock selection for Synchronous Ethernet, T1 or E1 line timing sources, and external inputs.
Configuring external clock synchronization and automatic clock selection requires making clock selection, quality level, and priority considerations. The clock source selection algorithm is used to pick the two best upstream clock sources from among the various sources on the basis of system configuration and execution criteria such as quality level, priority, and hardware restrictions.
You can configure several options for external clock synchronization.
MX 10003 routers support external clock synchronization and automatic clock selection for Synchronous Ethernet, T1 or E1 line timing sources, and external inputs.
MX240, MX480, MX960, MX2020, PTX3000, and PTX5000 routers support external clock synchronization using Synchronous Ethernet. Synchronous Ethernet is a physical layer technology that functions regardless of the network load and supports hop-by-hop frequency transfer, where all interfaces on the trail must support Synchronous Ethernet.
Currently, two types of clocking modes are supported on MX Series routers, the distributing clocking mode and the centralized clocking mode.
The Switch Control Board (SCB) supports distributed clocking mode. The Enhanced Switch Control Board—SCBE—supports centralized clocking mode and has one external clock interface.
The Enhanced Switch Control Board—SCBE2—supports centralized clocking mode and has two external clock interfaces external-0/0 and external-1/0. Note that the external-0/0 interface refers to the external interface on the SCB in slot 0 and the external 1/0 interface refers to the external interface on the SCB slot 1.
On SCBE2, you can configure the external synchronization options only on the external interface on the active SCB. Therefore, if the active SCB is in slot 0, then you can configure the external-0/0 interface only. If the active SCB is in slot 1, then you can configure the external-1/0 interface only.
The Enhanced Switch Control Board—SCBE3—provides improved fabric performance and bandwidth capabilities and supports centralized clocking mode. SCBE3 does not support BITS E1/T1 external interfaces.
On SCBE3, you can configure the external synchronization options only on the external interface on the active SCB. Therefore, if the active SCB is in slot 0, then you can configure the external-0/0 GPS interface only. If the active SCB is in slot 1, then you can configure the external-1/0 GPS interface only. In a non-redundant configuration the SCBE3-MX provides fabric bandwidth of up to 1 Tbps per slot (four fabric planes) and 1.5 Tbps per slot fabric bandwidth when all six fabric planes are used (with MPC10E line cards). The SCBE3-MX is supported on Junos 18.4R1 and later releases. It is supported on the MX960, MX480 and MX240 devices.
The PTX Series Packet Transport Routers support an external synchronization interface that can be configured to synchronize the internal Stratum 3 clock on the CCG to an external source, and then synchronize the chassis interface clock to that source.