Key points to note:
- A VUE Aux Core requests RxD session and channel metrics based on the configurable Aux Core parameters Stat Polling Enabled and Poll Interval. By default. Stat Polling is enabled and the Poll Interval is set to 60 seconds. RxD session and channel metric data collection begins at the time the session and channel are created for the RxD. The data collected for a DEPI session and channel is progressive, meaning the data is constantly incrementing over time as the session and channel exist. As such, the data for each Aux Core stat poll interval is represented as a "delta" from what was reported at "time now" minus the data from the last stat poll interval.
- There is a very small "measurement error" on the Dropped Ingress Packets metric (typically <.005%) that is attributable to minor data sampling interval time inaccuracies between the VUE and RxD. Therefore, observing Dropped Ingress Packets samples showing very small percentage values (e.g. < .005%) can be ignored.
The example below is the ideal scenario of a working channel. All data sent by VUE is received by the RxD for a DEPI session/channel. On the Session Input graph (left side), there are the following:
- l2tpDiscards
- Zero count. Representing that in what the VUE sent to the RxD for the session, the RxD did not discard anything.
- l2tpOos
- Zero count. Representing that in what the VUE sent to the RxD for the session, the RxD did not receive any out-of-sequence data.
- droppedIngressPackets
- Zero count. Representing that in what the VUE sent to the RxD for the session, the RxD did not drop any packets.
On the Channel Output graph (right side), we see that in what the RxD received and processed up from the L2TP layer, from within the RxD it did not have any Channel Packet Discards or Errors. It also did not drop any packets when transmitting out the RF channel.
The example below is a problematic scenario. On the Session Input graph (left side), there are the following:
- l2tpDiscards
- Zero count. Representing that in what the VUE sent to the RxD for the session, the RxD did not discard anything.
- l2tpOos
- About 20,000 frames sent by the VUE were received out-of-sequence by the RxD.
- droppedIngressPackets
- About 10% of the DEPI session frames sent by the VUE were dropped by the RxD.
NOTE: Enabling the VTM Metrics feature requires special configuration steps that must be
performed on Domain Manager. Contact the CommScope TAC to complete
those procedures.