Ptp Time For System Time And Oam Time; Ptp Within Routing Instances; System-Wide Atm Parameters - Alcatel-Lucent 7450 Basic System Configuration Manual

PTP Time for System Time and OAM Time

PTP has the potential to provide much more accurate time into the router than can be obtained
with NTP. This PTP recovered time can be made available for system time and OAM packet
time stamping to improve the accuracies of logged events and OAM delay measurements.
The mechanism to activate PTP as the source for these internal time bases is to allocate PTP
as a local server into NTP. This permits the NTP time recovery to use PTP as a source for
time and then distribute it within the router to system time and the OAM process. This
activation also affects the operation of the NTP server within the SR OS. The PTP server
appears as NTP stratum 0 server and therefore the SR OS will advertise itself as an NTP
Stratum 1 server to external peers and clients. This activation may impact the NTP topology.

PTP within Routing Instances

In addition to Base routing and IES services, PTP messaging is supported within VPRN
services on the 7750 SR and 7950 XRS platforms. The 7450 ESS supports PTP in the Base
routing instance. PTP messaging is not supported through the management router instance.
Only one PTP clock exists within the router and it is shared by all routing instances that have
access. Only one routing instance may have configured peers and only this routing context
can receive the time or frequency reference into the router (contain a PTP port in Slave state).
The dynamic peers are shared across all routing instances; if it is desired to control the
number of dynamic peers that can be consumed by a given routing instance then this must be
configured for that routing instance.

System-Wide ATM Parameters

On the 7750 SR, the atm-ping OAM loopback feature for can be enabled on an ATM SAP for
a period of time configured through the interval and the send-count parameters. When the
ATM SAP terminates on IES or VPRN services, a failure of the loopback state machine does
not bring down the Layer 3 interface. Only receiving AIS/RDI OAM cells or entering the
AIS/RDI state brings down the Layer 3 interface.
The atm-ping OAM loopback feature can be also be enabled on a continuous basis on an
ATM SAP terminating on IES or VPRN services. When the loopback state machine fails, the
Layer 3 interface is brought down.
The ATM OAM loopback parameters must be first enabled and configured in the
config>system> atm>oam context and then enabled in the IES or VPRN service interface
SAP atm oam context.
Refer to the IES and VPRN sections of the Layer 3 Services Guide for further information.
Basic System Configuration Guide
System Management
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