IEEE 1588v2 PTP

Precision Time Protocol (PTP) is a timing-over-packet protocol defined in the IEEE 1588v2 standard 1588 2008.

PTP can be deployed as an alternative timing-over-packet option to ACR. PTP provides the capability to synchronize network elements to a Stratum-1 clock or primary reference clock (PRC) traceable source over a network that may or may not be PTP-aware. PTP has several advantages over ACR. It is a standards-based protocol, has lower bandwidth requirements, can transport both frequency and time, and can potentially provide better performance.

There are five basic types of PTP devices, as listed below:

ordinary clock (master or slave)
boundary clock
end-to-end transparent clock
peer-to-peer transparent clock
management node

Table: IEEE 1588v2 PTP Support per Fixed Platform lists the types of PTP support on each fixed platform; Table: IEEE 1588v2 PTP Support per Card on the 7705 SAR-8 Shelf V2 and 7705 SAR-18 lists the types of PTP support on each adapter card for the 7705 SAR-8 Shelf V2 and the 7705 SAR-18.

Note:

All clock types, with the exception of transparent clock, support PTP messaging using UDP/ IPv4 or UDP/IPv6.
IPv6 messaging is supported on all platforms and cards listed in Table: IEEE 1588v2 PTP Support per Fixed Platform and Table: IEEE 1588v2 PTP Support per Card on the 7705 SAR-8 Shelf V2 and 7705 SAR-18 .
Boundary clocks support dual mode; that is, the clock can be configured for both IPv4 and IPv6. Dual mode is not supported on ordinary clocks; the clock can only be configured for IPv4 or IPv6.

Table: IEEE 1588v2 PTP Support per Fixed Platform
Sync Type	PTP Clock Type	7705 SAR-A 7705 SAR-Ax 7705 SAR-H 7705 SAR-Hc 7705 SAR-M 7705 SAR-Wx 7705 SAR-X
Freq	Ordinary Slave	✓
	Boundary Clock	✓
	End-to-End Transparent Clock	✓
	Ordinary Master	✓
Time of day/phase	Ordinary Slave	✓
	Boundary Clock	✓
	End-to-End Transparent Clock	✓ ¹
	Ordinary Master	✓ ²

All the platforms listed in Table: IEEE 1588v2 PTP Support per Fixed Platform support one ordinary slave clock, ordinary master clock, or boundary clock. The platforms also support an additional PTP clock for transparent clock functionality.

Table: IEEE 1588v2 PTP Support per Card on the 7705 SAR-8 Shelf V2 and 7705 SAR-18
Sync Type	PTP Clock Type	6-port Ethernet 10Gbps Adapter Card	8-port Gigabit Ethernet Adapter Card	Packet Microwave Adapter Card	2-port 10GigE (Ethernet) Adapter Card	10-port 1GigE/1-port 10GigE X-Adapter Card³
Freq	Ordinary Slave	✓	✓	✓	✓	✓
	Boundary Clock	✓	✓	✓	✓	✓
	End-to-End Transparent Clock
	Ordinary Master	✓	✓	✓	✓	✓
Time of day/phase	Ordinary Slave	✓	✓	✓	✓	✓
	Boundary Clock	✓	✓	✓	✓	✓
	End-to-End Transparent Clock
	Ordinary Master ⁴	✓	✓	✓	✓	✓

The 7705 SAR-8 Shelf V2 supports up to six ordinary slave clocks, ordinary master clocks, or boundary clocks. The 7705 SAR-18 supports up to eight ordinary slave clocks, ordinary master clocks, or boundary clocks.

Each of the cards listed in Table: IEEE 1588v2 PTP Support per Card on the 7705 SAR-8 Shelf V2 and 7705 SAR-18 supports one PTP clock.

A nodal clock is equipped in each CSM on the 7705 SAR-8 Shelf V2 and 7705 SAR-18 or directly on the fixed platforms listed in Table: IEEE 1588v2 PTP Support per Fixed Platform. Up to two PTP ordinary or boundary clocks can be configured per node as references to the nodal clock.

Each PTP slave clock can be configured to receive timing from up to two PTP master clocks in the network.