Hardware Timestamps - Juniper JUNOS OS 10.4 - FOR EX REV 1 Manual

Copyright © 2010, Juniper Networks, Inc.
ICMP timestamp probe
HTTP tests:
HTTP get probe (not available for BGP RPM services)
HTTP get metadata probe
UDP and TCP tests with user-configured ports:
UDP echo probe
TCP connection probe
UDP timestamp probe

Hardware Timestamps

To account for latency or jitter in the communication of probe messages, you can enable
timestamping of the probe packets (hardware timestamps). If hardware timestamps
are not configured, then timers are generated at the software level and are less accurate
than they would have been with hardware timestamps.
NOTE: EX Series switches support hardware timestamps for UDP and ICMP
probes. EX Series switches do not support hardware timestamps for HTTP
or TCP probes.
You can timestamp the following RPM probes to improve the measurement of latency
or jitter:
ICMP ping
ICMP ping timestamp
UDP ping
UDP ping timestamp
You should configure the requester (the RPM client) with hardware timestamps (see
Figure 96 on page 4000) to get more meaningful results than you would get without the
timestamps. Only the server port number needs to be configured on the responder (the
RPM server). If the responder supports hardware timestamps, it timestamps the RPM
probes. If the responder does not support hardware timestamps, RPM can only report
round-trip measurements that include the processing time on the responder.
NOTE: Hardware timestamps are supported on all EX Series switches.
Figure 96 on page 4000 shows the timestamps:
Chapter 141: Real-Time Performance Monitoring (RPM)
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