# Common types of curves

In DNC we often use curves simpler than UPP. Also, there are often known properties that simplify computations involving them.

Nancy provides specialized classes for many of these, which you can find in `Unipi.Nancy.NetworkCalculus`

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They provide simplified constructors and optimized operations.
An example:

`var sc = new RateLatencyServiceCurve(rate: 3, latency: 3);`

var ac = new SigmaRhoArrivalCurve(sigma: 4, rho: 1);