This International Standard specifies the 8-contact connector (plug and jack) and the assignments of its contact numbers for use in the physical interfaces of Integrated Services Digital Network (ISDN) primary rate access services conforming to ITU-T Recommendation I.431. In this International Standard, as in ITU-T Recommendation I.431, the term \'NT\' is used to indicate the network terminating layer 1 aspects of NT1s and NT2s, and the term \'TE\' is used to indicate terminal layer 1 aspects of TE1s, TAs and NT2s. NOTES This International Standard specifies only those connector dimensions required to ensure intermatability of plug and jack. Complete detailed specifications of the connector are the subject of IEC603-7, see annexC. ITU-T recognizes an alternative connection system which is not covered by this International Standard. It uses coaxial connectors as specified in IEC169-8 (see annexC), and is illustrated in annexB.