Lawful Interception (LI); Handover Interface and Service-Specific Details (SSD) for IP delivery; Part 4: Service-specific details for Layer 2 services (V2.2.1; Includes Diskette)
"The present document specifies Lawful Interception for an Access Provider that has access to layer 2 session information and that is not required to have layer 3 information. In this case@ the focus of Lawful Interception (LI) for IP Network Access is on the portion of the network@ commonly referred to as ""layer 2 interception""@ that facilitates subscriber access to the Public IP network. The present document describes the LI at the interception domain of the access network. The specification contains: ? a stage 1 description of the Lawful Interception service; ? a stage 2 description of the information flows between the functional entities (including the information elements involved) and triggering events; and ? a stage 3 description of the protocol and procedures to be used in mapping from stage 2 information flows and elements to Intercept Related Information (IRI) and Content of Communication (CC). The present document is consistent with the definition of the Handover Interface@ as described in TS 102 232-1 [2]. NOTE 1: Layer 3 interception is described in TS 102 232-3 [12]. NOTE 2: Layer 2 interception is not applicable to the PS domain of the GSM/UMTS networks (TS 123 060 [15])."