Lawful Access Feature: Switching Generic Requirements
Document Number GR-2973
Issue Number 04
Issue Date Apr 2000
Replaces SR-3727 Issue01
Components of this product are:
ABSTRACT: Issue 4 of GR-2973, Lawful Access Feature: Switching Generic Requirements, replaces Issue 3 of GR-2973.
GR-2973 provides generic requirements for a wireline switching feature in support of the Communications Assistance for Law
Enforcement Act (CALEA) of 1994. CALEA requires that a service provider be able to support lawful surveillance of the traffic in its
network. Lawful surveillance is the process of identifying a targeted set of traffic and delivering call-identifying information about
the traffic, and possibly the content of the traffic itself, to a remote law enforcement agency in real time.
The inclusion of generic requirements herein for a wireline switching feature in support of CALEA does not imply, nor should one
construe these generic requirements in such a fashion as to infer, that such wireline switching features are necessarily required by
the terms of CALEA to be provided to law enforcement by a Telcordia client company. The provision of wireline switching features in
support of CALEA is a matter of individual client company interpretation of the requirements of CALEA with reference to appropriate
This document represents an implementation of J-STD-025/J-STD-025A without any additional feature enhancements that would provide
surveillance capabilities beyond those specified in J-STD-025/J-STD-025A. The additional requirements in this document address
administration, delivery, maintenance, guidance on services, and security, which are excluded from J-STD-025/J-STD-025A, but are
required for the implementation of this feature.
This document applies to all wireline switches that support subscriber access interfaces, i.e., those switches solely providing
end-office functions and end-offices that also provide tandem functions. It applies to both Service Switching Point (SSP) end-offices
and non-SSP end-offices. Other elements within the network architecture that supports CALEA, such as the administration system, and
interfaces within the architecture are described at a high level to provide background and context for the Lawful Access Feature.
GR-2975 details the requirements of the administration system (or operations support system) to control the switches supporting
GR-2973 functionality. These two documents reference one another and are intended to function as a set.
The requirements are intended to support surveillance of specified traffic within a switch that originates from or requests
termination to a Directory Number (DN) assigned to an intercept subject served by that switch. A switch "serves" a DN if the subscriber
access interface associated with that DN is homed on that switch. This document assumes that surveillance on a given call is performed
in exactly one switch. Feature information and control information from features not resident on the switch serving the subject DN, or
that are not part of the subject's service, will not be reported.
This document provides requirements for the following telecommunications services and technologies: Plain Old Telephone Service
(POTS), Basic CENTREX lines, CLASS features, some Intelligent Network (IN) and Advanced Intelligent Network (AIN) services,
Integrated Services Digital Network Basic Rate Interface (ISDN BRI), including the support of X.25 packet data over ISDN, and
Electronic Key Telephone Service (EKTS).
Issue 4 of GR-2973 includes requirements for the following six punch list items: Content of subject-initiated conference calls;
party remove, join, drop on conference calls; subject-initiated dialing and signaling information; in-band and out-of-band signaling;
timing information; dialed digit extraction. Changes in this issue related to the punch list items include the following: added new
messages and parameters in Section 3, modified the CCC management rules in Section 4, removed the "Subject Transmit CCC Option" in
Section 4 for consistency with the Dialed-digit extraction punch list item, updated the service examples in Section 5, and updated
Appendix A to reflect the requirements mandated by the "Content of Subject-initiated Conference Calls" item.
When using GR-2973, you may need to refer to GR-474, GR-507, GR-510, TR-TSY-000821, and GR-2975; ANSI T1.107;
and ITU-T E.164, X.25, X.121, and X.733 (ISO/IEC 10164-4). You may also want to refer to TR-TSY-000473, GR-820, GR-822,
TR-TSY-000827, GR-828, GR-1093, GR-1298, TIA/EIA J-STD-025 and J-STD-025A, ANSI T1.260, FCC 99-230 (CC Docket No.
97-213), and IETF RFC 1356.
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