CQM Graphs: Difference between revisions

|'''Speed bumps'''

Latency humps like this are normally a sign of back-haul congestion. They normally show on all lines on an exchange or BRAS at once at the same time of day, and only show at certain (busy) times. The clue here is the consistently high latency even when little or no traffic flowing.

|[[File:Cqm-dropping.png]]

|Going off line is shown in purple, and this is often associated with packet loss (red). Where a line has occasional drops they are shown as purple lines. However in some case a line can deteriorate over a period of time, staying on line less and less until solid purple (off line). On the live graphs a line that is currently off line has a red square in the bottom right corner where as a line that is on-line has a green square.

|[[File:Cqm-congestion.png]]

|A congested link in the back-haul can show as loss or latency humps on an idle line, but in some cases, like this, it can show only where there is traffic on the line. The symptoms are latency spikes like this (green spikes) even when there is very low usage. Compare to normal graph below.