Ntwrk clcls s " st f mthmtcl rslts whch gv nsghts nt mn-md systms sch s cncrrnt prgrms, dgtl crcts nd cmmnctn ntwrks." Ntwrk clcls gvs thrtcl frmwrk fr nlysng prfrmnc grnts n cmptr ntwrks. s trffc flws thrgh ntwrk t s sbjct t cnstrnts mpsd by th systm cmpnnts, fr xmpl:
dt lnk cpcty
trffc shprs (lky bckts)
cngstn cntrl
bckgrnd trffc
Ths cnstrnts cn b xprssd nd nlysd wth ntwrk clcls mthds. Cnstrnt crvs cn b cmbnd sng cnvltn ndr mn-pls lgbr. Ntwrk clcls cn ls b sd t xprss trffc rrvl nd dprtr fnctns s wll s srvc crvs.
Th clcls ss "ltrnt lgbrs ... t trnsfrm cmplx nn-lnr ntwrk systms nt nlytclly trctbl lnr systms."
Crrntly, thr xsts tw brnchs n ntwrk clcls: n hndlng dtrmnstc bndd, nd n hndlng stchstc bnds.