KSwitch D10 MMT Managed Time Sensitive Ethernet Switch - Preliminary User Guide, Rev. 0.99
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TSN Features
Time-Sensitive Networking (TSN) is a number of IEEE 802 standards that are defined by the IEEE TSN task group.
These standards define mechanisms for deterministic real-time communication over Ethernet networks.
The following links gives an overview and status of the various TSN standards https://en.wikipedia.org/wiki/Time-
Sensitive_Networking and http://www.ieee802.org/1/pages/tsn.html.
This chapter covers:
Credit based shaper (IEEE 802.1Q-2014)
Time aware shaper (IEEE 802.1Qbv)
Frame preemption (IEEE 802.1Qbu)
FRER (Frame Replication and Elimination , 802.1CB-2017), Cut-through (IEEE 802.1Qcc) and Per-Stream Filtering and
Policing (PSFP, IEEE 802.1Qci) are supported by the KSwitch-D10 as well. For more information, refer to Chapter 9.1.4:
. Switch CLI Help or the Web Interface,
5.1.
Using TSN Functions with PTP Time Synchronisation
When using TAS and PSFP between network elements, it is required to have a common global time reference provided
by PTP. When booting the KSwitch-D10, it will take some time for a configured PTP application to locked to the
common time reference. It may cause malfunctioning of TAS and PSFP if a config-change is issued before the PTP
time is in a ‘Locked’ or ‘Locking’ state. A function that can delay the issue of config-change until PTP is Locked/Locking
or a configurable time has passed, can be configured with the CLI command:
tsn ptp-check.
The full set of configuration options for PTP exceeds the scope for this document. Refer to the help function of the CLI
or the Web Interface.
The syntax for the TSN delayed start function is:
Syntax Example:
tsn ptp-check procedure { none | ptp | wait }
tsn ptp-check ptp-port <0-3>
tsn ptp-check timeout <10-200>
no tsn ptp-check procedure
no tsn ptp-check ptp-port
no tsn ptp-check timeout
Where:
none
Procedure: Start TSN functions immediately without any delay
ptp
Procedure: Monitor the status of PTP time. Start if it is Locking or
Locked.If Locking or Locked is not achieved within wait time, then start
anyway
wait
Procedure: Wait timeout number of seconds before starting TSN functions
ptp-port
The PTP port to use for sensing PTP status
timeout
Set ptp-check-procedure timeout in seconds
Example:
(config)# tsn ptp-check procedure ptp
(config)# tsn ptp-check ptp-port 2
(config)# tsn ptp-check timeout 30
It is intended that after configuring
tsn ptp-check
, it should be saved to startup-config, and the delay function will
only be executed once after a 'power on' or 'reload cold'.