Diameter Flooding

In telecommunications, Diameter Flooding is a denial-of-service attack that overwhelms a Diameter peer (HSS, MME, PCRF, DRA) with high-rate requests on interfaces such as S6a, S9, or Sh. It can disrupt authentication, policy, and roaming. Defenses include rate limiting at the Diameter Edge Agent, origin-realm whitelisting, and category-based screening.

Categories: Core NetworkSignalingRoaming and Interconnect

Diameter Flooding in context

The mobile core carries subscriber sessions, mobility and policy. In 4G it is the EPC (MME, HSS, S/PGW); in 5G it is the Service-Based Architecture with AMF, SMF, UPF, AUSF, UDM and the NRF.

Signaling protocols carry the control-plane messages that set up calls, register subscribers and route SMS. SS7, Diameter, GTP-C and SIP are the four dominant families, and interconnect exposure of any of them is treated by GSMA as top-tier telecom risk.

To place Diameter Flooding in the wider telecom-security picture, review FS.07, FS.19, GGSN, GTP, GTP Firewall and HLR — each entry cross-references back to this page so you can walk the topic in either direction.

Related terms

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