(1) "Extended area service" (EAS) means a calling service between two exchanges or among exchanges within a region, provided as local service at local exchange rates or at an increment to local exchange rates rather than at toll prices.

(2) "Exchange-to-exchange EAS" means EAS between two exchanges, generally when outside a designated region.

(3) "Petitioned exchange" means the exchange to which another exchange petitions for EAS, or when consideration of EAS is other than by petition, the larger exchange (based on the number of main billed accounts) , or in the context of a region, the common exchange or, if none, the largest exchange.

(4) "Petitioning exchange" means the exchange petitioning for EAS with another exchange, or when consideration of EAS is other than by petition, the smaller exchange.

(5) "Region" means an area wherein more than one exchange share a community of interest with a common exchange or wherein successful, practical, or equitable EAS necessitates intermediate, intervening, or area exchanges be considered as required exchanges.

(6) "Regional EAS" means EAS among exchanges within a designated region.

(7) "Required exchange" means an exchange that is not petitioned or petitioning, but is likely to be indispensable to successful, practical, and equitable EAS between the petitioned and petitioning exchange or among exchanges within a region.