Instruction manual

Page 1645 of 3156
Features and Services
Hong Kong Digital Trunk Interface
Contents
The following are the topics in this section:
Feature description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1645
Operating parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1646
Feature interactions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1646
Feature packaging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1646
Feature implementation . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1646
Task summary list . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1646
Feature operation . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1647
Feature description
This feature modifies the 1.5 Mbps Digital Trunk Interface (DTI) in order to
allow the Meridian 1 to interface with the Hong Kong Telephone Company
(HKT). The design modification alters the Dual-tone Multifrequency
(DTMF) signaling protocol to conform with the HKT requirements. This
DTMF design modification involves altering the AB bit protocol used in the
DID/TIE convention, which is the convention used for the Meridian 1 to HKT
connectivity. The AB bit values for the normal DID/TIE convention are
reversed for the HKT interface. For example, if the normal convention for a
DID/TIE going off-hook requires that AB bit values 0 and 0 be sent to the far
end, the convention for HKT is that AB bit values 1 and 1 be sent.