PEI (Permanent Equipment Identifier)

In telecommunications, the PEI is the 5G equivalent of the IMEI, identifying the mobile equipment itself rather than the subscriber. It is checked by the network (potentially against an EIR) to detect stolen or non-compliant devices.

Categories: Identity and SubscriberInternet and RoutingIoT

PEI in context

Subscriber identifiers (IMSI, SUPI, MSISDN, IMEI) anchor authentication, charging and lawful interception. Any protocol that leaks a permanent identifier is treated as a privacy defect, which is why 5G introduced SUCI concealment on the air interface.

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 PEI in the wider telecom-security picture, review CGNAT, Demarcation Point (Demarc), DSL, DSLAM, Endpoint and IP Address — each entry cross-references back to this page so you can walk the topic in either direction.

Related terms

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.