What is Connection Utilization Coding and why should you enable it?

CUC (Connection Utilization Coding) is the functionality that applies a color and/or width to a network connection line, according to its utilization level. The displayed value is the highest measured utilization (up or download) of both endpoints of a connection.

CUC helps in detecting potential problem spots, congestion or traffic anomalies!

How to enable Connection Utilization Coding

CUC is enabled by default and requires no configuration. However, CUC works by collecting LLDP information via SNMP from all equipment that supports it.

For the best results, enable SNMP support by default on as many devices as possible. Most commercially used network equipment and operating systems support LLDP. However, this must often be switched on manually.

More information about LLDP can be found here

If the conditions are not met, CUC can not determine the use of a connection and the connection is considered “unmanaged”. In this case the line color is set to gray and the width to 3 pixels.

Coding options

CUC offers a couple of coding options that can be set on the Administration | Various system settings page.

Yellow circle: if the util% can not be calculated due to missing information, the fallback (displaying bps) is used.


If the traffic on a network is very low, let’s say less than 5% (it’s beyond working hours or your network is over-dimensioned) and you still want to get an indication of where the most traffic is flowing through your network is, you can set a scale factor.

The scale factor ranges from 1 to 10 where scale factor 1 effectively means “No scaling”. When scaling is applied, each Map page will get a notification in the bottom-right corner.

Finally, there’s also the option Relative which means that all connections are color-coded relative to the connection with the highest utilization.

Custom color mapping

Besides the scale factor you can also define your own color map by using the integrated color picker. Just click an existing color, select a new one and save your settings! See the coding options screenshot above.