Cisco A9K-SIP-700 User Manual

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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.
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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-Request/Delay-Response Packets: Rates from 128 packets-per-second to 16
seconds-per-packet.
◦
Announce Packets: Rates from 8 packets-per-second to 64 packets-per-second.
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Transport Mechanism: G.8265.1 profile only supports IPv4 PTP transport mechanism.
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Mode: G.8265.1 profile supports transport of data packets only in unicast mode.
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Clock Type: G.8265.1 profile only supports Ordinary Clock-type (a clock with only one PTP port).
•
Domain Numbers: The domain numbers that can be used in a G.8265.1 profile network ranges from 4
to 23. The default domain number is 4.
•
Port Numbers: All PTP port numbers can only be 1 because all clocks in a this profile network are
Ordinary Clocks.
G.8265.1 profile defines an alternate algorithm to select between different master clocks based on the local
priority given to each master clock and their quality levels (QL). This profile also defines Packet Timing
Signal Fail (PTSF) conditions to identify the master clocks that do not qualify for selection. They are:
•
PTSF-lossSync condition: Raised for master clocks that do not receive a reliable stream of Sync and
Delay-Resp messages. Cisco IOS XR software requests Sync and Delay-Resp grants for each configured
master clock to track the master clock with this condition.
•
PTSF-lossAnnounce condition: Raised for master clocks that do not receive a reliable stream of Announce
messages.
•
PTSF-unusable condition: Raised for master clocks that receives a reliable stream of Announce, Sync,
and Delay-Resp messages, but not usable by slave clocks. Cisco IOS XR software does not use this
condition.
States of Ports
State machine indicates the behavior of each port. The possible states are:
• INIT – Port is not yet ready to participate in PTP.
• LISTENING – First state when a port becomes ready to participate in PTP: port listens for PTP masters
for a (configurable) period of time.
• PRE-MASTER – The port is about to go into MASTER state.
• MASTER – The port is provides timestamps for any listening slave/boundary clocks.
Cisco ASR 9000 Series Aggregation Services Router System Management Configuration Guide, Release 5.1.x
237
Configuring PTP
States of Ports

Cisco A9K-SIP-700 Specifications

General

Brand	Cisco
Model	A9K-SIP-700
Category	Network Router
Language	English