MDF2 (Mediation and Delivery Function 2 (IRI))

Also known as: Mediation Delivery Function 2

MDF2 is the 3GPP lawful-interception function (TS 33.126, TS 33.127, TS 33.128) that mediates Intercept Related Information from POIs, applies correlation and formatting, and delivers it to the LEA over the LI_HI2 interface. It is the IRI counterpart of MDF3 and is deployed inside the operator's segregated LI domain.

Categories: Threats and AttacksProtocols and StandardsOperations and Business

MDF2 in context

Telecom threats range from opportunistic SMS phishing and SIM swap to nation-state grade location tracking and lawful-interception abuse. The common thread is that most attacks exploit the inherited trust model of legacy signaling. SS7 and Diameter were designed for a closed operator community that no longer exists.

Telecom security is written into standards from 3GPP, GSMA, ETSI, IETF and ITU-T. Understanding which body owns which specification, and how the specs interlock (for example 3GPP TS 33.501 with GSMA FS.34 for 5G SBA security), is essential for both design and audit work.

To place MDF2 in the wider telecom-security picture, review MDF3, X2 (LI), Mediation Device (Lawful Interception), ETSI TS 103 221, IRI and Patch.

Related terms

Related topic hubs

  • Diameter Attacks S6a IDR/PUR/CLR abuse, subscriber tracking, LTE signaling attacks.

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