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 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.

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

To place Subnet in the wider telecom-security picture, review Suricata, CSIRT, Segment Routing, 3GPP, LEO and ATSSS.

Related terms

Related topic hubs

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

More from the TelcoSec Glossary

Browse the full TelcoSec Glossary, the Ultimate Guide to Mobile Network Security, or the P1 Arsenal of telecom-security tools.