ABSTRACT: Metallic Special Access services, MT1 through MT3, are nonswitched services used for applications such as alarm, pilot wire protective relaying, and dc tripping protective relaying. Telegraph Special Access Service, TG1 and TG2, are also nonswitched services used for applications such as teletypewriter, telegraph grade control/remote metering, telegraph grade channel, telegraph grade extension, and telegraph grade entrance facilities.

This Technical Reference (TR) describes the view of Telcordia on both Metallic and Telegraph Grade Special Access Services and covers distinguishing service features, technical requirements, and valid interfaces. The document provides a quantitative and qualitative description of the services and their interfaces at the End User Point Of Termination (EU-POT) and at the Interexchange Carrier Point Of Termination (IC-POT) so that compatible operation will be achieved.

TR-NPL-000336 replaced PUB-62502.

GR-334, TR-NWT-000335, TR-NPL-000336, GR-337, GR-338, TR-NPL-000339, TR-NPL-000340, TR-NWT-000341, and GR-342 were formerly bundled as TR-TSY-000333.