> # Viewing ISL Traffic and Errors Information

> 1. From the menu bar, choose Performance > ISLs/Trunks.

> You see the ISL Traffic and Errors pane. This panel displays the ISL information for the end devices in that scope. You can reduce or expand the scope of what is displayed by using the scope menu.

> 2. You can use the drop-down to filter the view by 24 hours, Week, Month and Year.

> Notation NaN (Not a Number) in the data grid means that the data is not available.

> There are variations to this procedure. In addition to these basic steps, you can perform the following steps to view detailed information for ISLs:

> - To change the time range for this graph, select it from the drop-down list in the upper-right corner.
> - To view the detailed information for a specific period, drag the slider control to choose the time interval for which you need the information.
> - Use the chart icons to view the traffic chart in varied views.You can also use the icons to Append, Predict and Interpolate Data. To view real-time information, choose Real Time from the drop-down list in the upper right corner. The real-time data is updated in every 10 seconds.
> - To export the data into a spreadsheet, click the Export to Excel icon in the upper-right corner and then click Save.
> - For the Rx/Tx calculation, see the Rx/Tx Calculation section.

> Note If the performance tables do not contain any data, see the Performance Manager Collections section to turn on performance.

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