Does the Model include a mechanism to monitor multicast TLV message traffic - advanced warning of a storm?
Closed this issue · 2 comments
On discussion with kierank :
The problem use case is that PTP instances are responding to a multicast TLV message with a multicast TLV response. While this is prohibited by the SMPTE profile, it happens frequently in practice.
The question is - irrespective of what profile is being used: Does the model include a mechanism that will help with monitoring and give advanced warning of the onset of a TLV message storm?
As background relating to issue #13 (but is separate to this monitoring question)
1588-2019 15.2 PTP management mechanism states:
"PTP Profiles may specify the use of multicast and/or unicast addressing for PTP management messages
Unless otherwise specified in the applicaple PTP Profile, a PTP management message that is a response to another PTP management message may use a different form of addressing from the PTP management message to which it is a response."
In the st-2059-2-monitoring-ds container there are two counters:
management-message-tx yang:zero-based-counter32
management-message-rx yang:zero-based-counter32
If these have been implemented in a device, they can be interrogated at regular intervals and the rate of change of management messages tracked against time.
In the event of a message storm the number of received management messages would grow in something like an exponential manner. Ie an apparent slow initial increase that then can start to escalate rapidly.
If a system wishes to monitor for message storms, then one or more end points should implement the management-message counters, and the monitoring control system should retrieve these counter values at appropriate time intervals and track the management message rates.