Page 617 of 1814International ISDN PRI Feature description and administration624Electronic Switched NetworkinterworkingContentsThe following are the topics in this section:Feature description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 617Operating parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 619Feature interactions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 619Feature packaging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 619Feature implementation . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 619Task summary list . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 619ESN default call types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 619ESN access code insertion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 621Private Network Hopoff . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 622Private Network Overflow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 623Feature operation . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 624Feature descriptionThe Electronic Switched Network (ESN) operates within ISDN, supportingNetwork Class of Service (NCOS) capability. The tables in this moduledescribe which ESN features are available over ISDN and illustrate ESNcapabilities over ISDN.Network Class Of Service (NCOS) information is embedded in SETUPmessages, and provides the means to control a user’s eligibility for thefollowing:• access routes
