Graph names are text and up to 20 characters. Only letters, numbers, @, -, and . are allowed. All other characters are removed. It is recommended that names complying with this are used. Any graph name that you try and use that is too long will be replaced with one that uses part of the name and a hash to try and ensure a consistent unique graph name is applied.

Graphs can be defined in some configuration settings such as interface names.

Graphs can also be created dynamically in some cases, e.g. L2TP based graphs are made based on the Chargeable-User-Id, Calling-Station-Id or User-Name for a connected line, and so can be defined from the RADIUS authentication response. It is recommended that the circuit ID is used where available, e.g. from BT platform RADIUS.

The number of graphs is limited depending on memory, but the design is to allow for 100,000 distinctly named graphs. Dynamic circuits simply do not have graphs on them if this number is exceeded. Graphs not used for more than the data retention time are discarded automatically.