Anycast (IP Anycast)

Anycast is a routing technique where the same IP prefix is advertised from multiple locations via BGP, and traffic is delivered to the topologically nearest instance. Used by operators for resilient DNS, SEPP and NEF frontends, and CDN edges. Anycast improves DDoS resilience by spreading attack traffic across POPs and reduces latency but complicates stateful signaling that assumes a single terminating node.

Categories: Core NetworkSignalingRoaming and Interconnect

Anycast 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 Anycast 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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