QCI (QoS Class Identifier)

In telecom networks, the QCI is the LTE scalar value that selects a standardized set of QoS characteristics applied to a bearer, including resource type, priority, packet delay budget, and packet error rate. Each QCI corresponds to a defined service profile such as conversational voice or streaming video.

Categories: Protocols and StandardsEncryption and Cryptography

QCI 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.

Cryptography in telecom spans air-interface ciphers (A5/1, A5/3, ZUC, SNOW, NEA/NIA), transport (IPsec, TLS) and identity (AKA, 5G-AKA, EAP-AKA'). Weak or downgradeable ciphers remain a live risk on 2G/3G fallback.

To place QCI in the wider telecom-security picture, review Jitter, MEC, WPA2, XMPP, Zigbee and ETSI ISG MEC — 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.