102 232 is the worldwide standard that defines the HI2 and HI3
interfaces. CSPs use these interfaces to transmit intercepted
signaling (HI2) and content (HI3) to LEAs.
The base of TS 102 232 is called "part 1".
It defines the basic functional elements of an
A mediation function is located in the network
of a CSP.
It translates intercepted material into a standardized
format. After formatting, it delivers information to the
Law Enforcement Monitoring Facility (LEMF).
A LEMF is hosted by an
LEA. It is
responsible for receiving data from mediation functions.
Once securely stored, analysis on the information is
Part 1 also contains the technical implementation of the
data format. It is defined as a
PDU. Every piece
of intercepted information is delivered using this PDU.
The PDU is encoded using ASN.1. This encoding is similar to
binary data formats such as protobuf. And is optimized
for high performance.
PDUs are transmitted across IP networks. As these networks
may be unreliable, part 1 describes several mechanisms to
survive failure in the delivery networks.
This ranges from PDU distribution mechanisms to buffering
PDUs in the mediation function.
Download ETSI TS 102 232-1
Interception of e-mail protocols such as POP3, IMAP and SMTP is
described in part 2. Part 2 also supports protocol agnostic
interception of e-mail.
Messaging services in general are also supported in this part.
Download ETSI TS 102 232-2
IP based intercepts are delivered using part 3. Services like
fixed line access and wifi are covered.
Download ETSI TS 102 232-3
In certain countries, a CSP may offer Layer-2 service to other
CSPs. If the LI obligation falls on the Layer-2 CSP, this
part can be used.
Download ETSI TS 102 232-4
Interception of SIP, RTP, MSRP (RCS) is supported by part 5.
As such, systems like IMS and services like RCS, VoLTE, VoWIFI
are intercepted using this specification.
Download ETSI TS 102 232-5
Circuit-switched based telephony is intercepted using part 6.
It provides an envelope for delivering the legacy
ETSI TS 101 671 specification.
Services such as POTS, ISDN, 2G telephony, 3G telephony and SMS
Download ETSI TS 102 232-6
Provides an envelope for 2G, 3G, 4G mobile data interception
using 3GPP TS 33.108.
For 5G, part 7 is the only delivery mechanism. The IRI and CC
payloads are defined in 3GPP TS 33.128 however.
Download ETSI TS 102 232-7