Subnet

A subnet is a logical subdivision of an IP network defined by a subnet mask or CIDR prefix, allowing administrators to segment networks for performance, security, and routing. Careful subnetting underpins network security architecture: separating user, server, management, and DMZ traffic into distinct subnets is a baseline hardening practice.

Categories: Protocols and StandardsInternet and Routing

Subnet in context

Telecom security is written into standards from 3GPP, GSMA, ETSI, IETF and ITU-T. Understanding which body owns which specification, and how they interlock, is essential for both design and audit work.

Telecom networks depend on Internet-style routing (BGP, DNS, MPLS) for interconnect. Route hijacks and DNS abuse can degrade or intercept signaling, which is why RPKI and DNSSEC are now standard hardening for carrier networks.

To place Subnet in the wider telecom-security picture, review 3G, 3GPP, A5/1, BGP, Digital Signature and GSMA Permanent Reference Documents (IR Series) — each entry cross-references back to this page so you can walk the topic in either direction.

Related terms

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