TelcoSec Glossary
699+ authoritative definitions covering telecom and mobile network security: 5G, SS7, Diameter, GTP, SEPP, IMS, Open RAN, roaming, fraud, and post-quantum cryptography. Maintained by P1 Security since 2011.
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1
2
3
4
5
- 5G: Fifth Generation Mobile Network
- 5G SA: 5G Standalone
- 5G NSA: 5G Non-Standalone
- 5G SBA: 5G Service-Based Architecture
- 5GNR: 5G New Radio
- 5G-AKA: 5G Authentication and Key Agreement
- 5G Reference Points
- 5G-GUTI: 5G Globally Unique Temporary Identifier
- 5QI: 5G QoS Identifier
- 5G LAN: 5G Local Area Network service
6
8
A
- AAA: Authentication, Authorization, and Accounting
- ACL: Access Control List
- ADSL: Asymmetric Digital Subscriber Line
- AES: Advanced Encryption Standard
- A5/0: GSM Null Cipher
- A5/1: GSM Standard Cipher
- A5/2: GSM Weaker Cipher
- A5/3: GSM Modern Cipher (UEA1)
- AKA: Authentication and Key Agreement
- AMF: Access and Mobility Management Function
- AMPS: Advanced Mobile Phone System
- Anomaly Detection
- Any-Time Interrogation (ATI)
- AP: Access Point
- API: Application Programming Interface
- APT: Advanced Persistent Threat
- ARPU: Average Revenue Per User
- Artificial Traffic Inflation: Fraud Context
- ASN: Autonomous System Number
- Attack Surface Mapping
- Authentication
- Authorization
- AUSF: Authentication Server Function
- Availability
- AF: Application Function
- AKA Linkability Attack
- Account Takeover (ATO)
- APN: Access Point Name
- A1 Interface: Non-RT RIC to Near-RT RIC Interface
- AIT: Artificially Inflated Traffic
- ATSSS: Access Traffic Steering, Switching and Splitting
- AES-GCM: AES in Galois/Counter Mode
- Anycast: IP Anycast
B
- Backhaul
- Bandwidth
- Base Station (BS)
- Behavioral Signaling Detection
- BGP: Border Gateway Protocol
- BGP Hijacking
- Billing System
- Blue Team
- Botnet
- Broadband
- BSS: Business Support System
- BTS: Base Transceiver Station
- BTS Impersonation (Fake BTS)
- BSF: Binding Support Function
- Bidding-Down Attack
- BEREC: Body of European Regulators for Electronic Communications
- BGCF: Breakout Gateway Control Function
- Bypass Fraud: Interconnect Bypass Fraud
- BGP Hijack: Border Gateway Protocol Hijack
C
- CAMARA Project
- CAP: CAMEL Application Part
- Capacity Planning
- CAPEX: Capital Expenditure
- CASB: Cloud Access Security Broker
- CDMA: Code Division Multiple Access
- Cell Phone (Mobile Phone)
- Certification Authority (CA)
- CGNAT: Carrier Grade Network Address Translation
- Charging System
- Cipher
- Cipher Downgrade Attack
- CLI Spoofing: Calling Line Identification Spoofing
- Cleartext (Plain Text)
- Cloud RAN
- Conformance Testing
- Confidentiality
- Control Plane Security
- Core Network
- Core Network Security Assessment
- CPE: Customer Premises Equipment
- Cryptanalysis
- Cryptography
- CSCF: Call Session Control Function
- CSPM: Cloud Security Posture Management
- CVE: Common Vulnerabilities and Exposures
- Cybersecurity
- Chain of Custody
- CHF: Charging Function
- CU/DU/RU Split
- Carrier Aggregation
- CER Directive: Critical Entities Resilience Directive
- CSFB: Circuit-Switched Fallback
- CAPIF: Common API Framework
- CALEA: Communications Assistance for Law Enforcement Act
- CVD: Coordinated Vulnerability Disclosure
- CSIRT: Computer Security Incident Response Team
- Call Spoofing: Calling Line Identification Spoofing
- CAMEL: Customised Applications for Mobile networks Enhanced Logic
- Curve25519: Curve25519 (X25519 ECDH)
- CC (LI): Content of Communication
- CLI Refile: CLI Refile / A-Number Manipulation
- CRQC: Cryptanalytically-Relevant Quantum Computer
D
- Data Localization
- Dayparting
- Detection Engineering
- DDoS: Distributed Denial of Service
- Decryption
- Demarcation Point (Demarc)
- Denial of Service (DoS)
- Diameter
- Diameter Interconnect Security
- Digital Signature
- DLP: Data Loss Prevention
- DMZ: Demilitarized Zone
- DNS: Domain Name System
- DOCSIS: Data Over Cable Service Interface Specification
- DRP: Disaster Recovery Plan
- DSL: Digital Subscriber Line
- DSLAM: DSL Access Multiplexer
- Defense in Depth
- Diameter Flooding
- DSS: Dynamic Spectrum Sharing
- DPI: Deep Packet Inspection
- Deception Technology
- DNN: Data Network Name
- DTLS-SRTP: DTLS Extension to Establish Keys for SRTP
- Data Retention: Telecom Data Retention
- DEA: Diameter Edge Agent
- DetNet: Deterministic Networking
- DTLS: Datagram Transport Layer Security
- DoT: DNS over TLS
- DoH: DNS over HTTPS
- DNSSEC: Domain Name System Security Extensions
- DDoS Reflection: Reflection/Amplification Denial-of-Service Attack
E
- E.164
- E911: Enhanced 911
- EAP: Extensible Authentication Protocol
- EDGE: Enhanced Data Rates for GSM Evolution
- EDR: Endpoint Detection and Response
- Egress
- EIR: Equipment Identity Register
- Encryption
- Endpoint
- eSIM (Embedded SIM, eUICC)
- ETSI: European Telecommunications Standards Institute
- Event Logging
- Exfiltration
- Exposure Mapping
- eSIM Profile Theft
- EECC: European Electronic Communications Code
- ENISA: European Union Agency for Cybersecurity
- ETSI ISG NFV
- ETSI ISG MEC
- EPS Fallback
- Edge Computing
- EES: Edge Enabler Server
- EEC: Edge Enabler Client
- ECS: Edge Configuration Server
- E2 Interface: O-RAN Near-RT RIC to E2 Node Interface
- E2AP: E2 Application Protocol
- E2SM: E2 Service Model
- EAP-AKA′: Extensible Authentication Protocol – AKA Prime
- E-CSCF: Emergency Call Session Control Function
- ENUM: E.164 Number Mapping
- ETSI TS 103 221: Internal Network Interfaces for Lawful Interception
- eUICC: Embedded Universal Integrated Circuit Card
- eMBB: enhanced Mobile Broadband
- ECDSA: Elliptic Curve Digital Signature Algorithm
F
- FASG: GSMA Fraud and Security Group
- FCC: Federal Communications Commission
- FDD: Frequency Division Duplex
- Femtocell
- Firewall
- Firmware
- Fixed Wireless Access (FWA)
- Flash Call Fraud
- Fronthaul
- Fuzzing: Telecom Protocols
- FS.07: GSMA Reference Document
- FS.11: GSMA Vulnerability Disclosure Framework
- FS.19: GSMA Fraud and Security Group Recommendations
- FS.36: 5G Interconnect Security Guidelines
- F1 Interface
- FS.20: GPRS/GTP Security
- FS.21: Interconnect Signalling Security Recommendations
- FS.31: Baseline Security Controls
- FS.40: 5G Security Guide
- Flash Call: Flash Call Authentication
G
- GGSN: Gateway GPRS Support Node
- Global Title Abuse
- GMSC: Gateway Mobile Switching Center
- GNSS: Global Navigation Satellite System
- GNSS Jamming
- GNSS Spoofing
- GPRS: General Packet Radio Service
- Grey Routing
- GRE: Generic Routing Encapsulation
- GSM: Global System for Mobile Communications
- GSMA: GSM Association
- GSMA Open Gateway
- GSMA Permanent Reference Documents (IR Series)
- GTP: GPRS Tunneling Protocol
- GTP Firewall
- GRX: GPRS Roaming Exchange
- GTP-C Spoofing
- GTP-U Smuggling
- GSMA SCAS: Security Assurance Specification
- GSMA T-ISAC: Telecommunications Information Sharing and Analysis Centre
- GPSI: Generic Public Subscription Identifier
- GBR / Non-GBR Bearers
- GUAMI: Globally Unique AMF Identifier
- GDPR: General Data Protection Regulation
- Grey Route: SMS Grey Route
- GBA: Generic Bootstrapping Architecture
- GTP-U: GTP User Plane
- GTP-C: GTP Control Plane
- GUTI: Globally Unique Temporary Identifier
- Grey Route SMS: Grey-Route SMS
- GTP Security: GPRS Tunneling Protocol Security
H
- Handoff (Handover)
- HDSL: High-Bit-Rate Digital Subscriber Line
- HI1: Lawful Interception (Handover Interface 1)
- HI2: Lawful Interception (Handover Interface 2)
- HI3: Lawful Interception (Handover Interface 3)
- HLR: Home Location Register
- HLS: HTTP Live Streaming
- HTTP/2 Security in 5G
- HSS: Home Subscriber Server
- HTTP: Hypertext Transfer Protocol
- HTTPS: HTTP Secure
- Hardening
- HKDF: HMAC-based Key Derivation Function
- HMAC-SHA256: Keyed-Hash Message Authentication Code with SHA-256
- Hybrid KEM: Hybrid Post-Quantum / Classical KEM
- HNDL: Harvest-Now-Decrypt-Later
I
- IAP: Intercept Access Point
- IAMF: Identity and Access Management Framework
- IBCF: Interconnection Border Control Function
- ICCID: Integrated Circuit Card Identifier
- ICT: Information and Communications Technology
- ICMP: Internet Control Message Protocol
- IDS: Intrusion Detection System
- IETF: Internet Engineering Task Force
- IGW: Internet Gateway
- ILEC: Incumbent Local Exchange Carrier
- IMS: IP Multimedia Subsystem
- IMEI: International Mobile Equipment Identity
- IMSI: International Mobile Subscriber Identity
- IMSI Catcher (Cell Site Simulator)
- Indicators of Compromise (Telecom IoCs)
- IN: Intelligent Network
- Incident Response
- Ingress
- Insider Threat
- Integrity
- Interconnection
- Interconnect Security Model
- Inter-Network Function Authentication
- Inter-PLMN Security
- IoT: Internet of Things
- IP: Internet Protocol
- IP Address
- IPS: Intrusion Prevention System
- IPv6
- IPsec: IP Security
- IRSF: International Revenue Share Fraud
- ISDN: Integrated Services Digital Network
- iSIM: Integrated SIM
- ISP: Internet Service Provider
- ISUP: ISDN User Part
- ITU: International Telecommunication Union
- IVR: Interactive Voice Response
- IPX: IP Packet Exchange
- Interconnect Bypass Fraud
- IPUPS: Inter-PLMN UP Security
- IMS-AKA: IMS Authentication and Key Agreement
- I-CSCF: Interrogating Call Session Control Function
- IR.92: GSMA IR.92 IMS Profile for Voice and SMS
- IR.94: GSMA IR.94 IMS Profile for Video Telephony
- IR.21: Roaming Data Sheet
- IKEv2: Internet Key Exchange version 2
- IRI: Intercept Related Information
J
K
L
- LA: Location Area
- LAN: Local Area Network
- Last Mile
- Latency
- Lawful Interception
- Lawful Interception Abuse Risk
- Lawful Interception Architecture
- LEO: Low Earth Orbit (Satellite)
- Location Tracking Attacks
- LTE: Long Term Evolution
- LTE-Advanced (LTE-A)
- Local Loop Unbundling (LLU)
- Lateral Movement (Telecom)
- Lawful Intercept: Lawful Interception
- LTE-M: LTE for Machines (Cat-M1)
M
- MAC: Medium Access Control
- MAC Address
- MAC Filtering
- Machine Learning (ML)
- Malware
- Man-in-the-Middle (MITM)
- Management Plane
- Massive MIMO
- MAP: Mobile Application Part
- MAP Security
- MCC: Mobile Country Code
- MEC: Multi-Access Edge Computing
- Media Gateway
- Mediation Device (Lawful Interception)
- Mediation System
- Metadata
- Metadata Retention
- Mitigation
- MNC: Mobile Network Code
- Mobile Network
- MNO: Mobile Network Operator
- MNP: Mobile Number Portability
- Modulation
- Monitoring
- MPLS: Multiprotocol Label Switching
- MSC: Mobile Switching Center
- MTBF: Mean Time Between Failures
- mTLS: Mutual TLS
- MTTR: Mean Time To Recovery
- MUX: Multiplexer
- MVNO: Mobile Virtual Network Operator
- MSSP: Managed Security Service Provider
- MDR: Managed Detection and Response
- MITRE FiGHT: 5G Hierarchy of Threats
- MITRE D3FEND
- Midhaul
- MEC Security
- MGCF: Media Gateway Control Function
- MTSI: Multimedia Telephony Service for IMS
- mMTC: massive Machine-Type Communications
- MDAF: Management Data Analytics Function
- MACsec: Media Access Control Security (IEEE 802.1AE)
- MDF2: Mediation and Delivery Function 2 (IRI)
- MDF3: Mediation and Delivery Function 3 (CC)
- MPLS-TE: MPLS Traffic Engineering
- ML-KEM: Module-Lattice-Based Key-Encapsulation Mechanism (FIPS 203)
- ML-DSA: Module-Lattice-Based Digital Signature Algorithm (FIPS 204)
N
- N32 Interface (5G)
- NAC: Network Access Control
- NAT: Network Address Translation
- NB-IoT: Narrowband IoT
- NESAS: Network Equipment Security Assurance Scheme
- Network Exposure Function (NEF)
- Network Slicing
- NIST: National Institute of Standards and Technology
- Noise
- NOC: Network Operations Center
- NPAI: Network Provided Calling Line Identification Presentation
- NRA: National Regulatory Authority
- NRF: Network Repository Function
- NSA: National Security Agency
- NTP: Network Time Protocol
- NTN: Non-Terrestrial Networks
- Numbering Plan
- NRF Poisoning
- N32 Tampering
- NWDAF: Network Data Analytics Function
- N3IWF: Non-3GPP Interworking Function
- NDR: Network Detection and Response
- NTA: Network Traffic Analysis
- NetFlow / IPFIX / sFlow
- NIS2 Directive: Network and Information Security Directive 2
- N32-c: N32 Control Plane
- N32-f: N32 Forwarding Plane
- NSSF: Network Slice Selection Function
- NSSAI: Network Slice Selection Assistance Information
- Near-RT RIC: Near-Real-Time RAN Intelligent Controller
- Non-RT RIC: Non-Real-Time RAN Intelligent Controller
- Number Portability: Mobile / Local Number Portability
- NAF: Network Application Function
- NGAP: NG Application Protocol
- N1: N1 Reference Point
- N2: N2 Reference Point
- N4: N4 Reference Point
- N6: N6 Reference Point
- N9: N9 Reference Point
- Network Slice: 5G Network Slice
- N3: N3 Reference Point (gNB to UPF)
- N11: N11 Reference Point (AMF to SMF)
- N12: N12 Reference Point (AMF to AUSF)
- N8: N8 Reference Point (AMF to UDM)
- N2 Handover: N2-based Handover
O
- OAuth2 in 5G Core
- OASIS: Organization for the Advancement of Structured Information Standards
- OAM: Operations, Administration, and Maintenance
- OCS: Online Charging System
- OCSP: Online Certificate Status Protocol
- OFDM: Orthogonal Frequency Division Multiplexing
- OFDMA: Orthogonal Frequency Division Multiple Access
- OFCS: Offline Charging System
- Open RAN
- OpenSSL
- Operating System (OS)
- Operational Expenses (OPEX)
- Operational Security (OPSEC)
- Order Management
- OSPF: Open Shortest Path First
- OSS: Operations Support System
- OT: Operational Technology
- OTA: Over The Air
- OTP Bypass Attacks
- OAM Compromise
- O-RAN Alliance
- O-RAN Interfaces (A1, E2, O1, O2)
- OTT Bypass
- O-CU: O-RAN Centralized Unit
- O-DU: O-RAN Distributed Unit
- O-RU: O-RAN Radio Unit
- O1 Interface: O-RAN Management Interface
- O2 Interface: O-RAN SMO to O-Cloud Interface
- Open Fronthaul: O-RAN 7-2x Fronthaul Interface
- O-Cloud: O-RAN Cloud Platform
- ONAP: Open Network Automation Platform
P
- Packet
- Paging Attacks
- Patch
- PBX: Private Branch Exchange
- PBX Hacking
- PDN: Packet Data Network
- PGW: Packet Data Network Gateway
- PHY: Physical Layer
- PLMN: Public Land Mobile Network
- PoE: Power over Ethernet
- PRD: Permanent Reference Document
- Private 5G
- Privacy by Design
- Provide Subscriber Information (PSI)
- PSTN: Public Switched Telephone Network
- Pentest: Penetration Testing
- Patch Management
- Purple Team
- PEI: Permanent Equipment Identifier
- Piercer Attack
- Port-Out Fraud
- PBX Dial-Through Fraud
- PCAP: Packet Capture
- PRINS: PRotocol for N32 INterconnect Security
- PLMN ID: Public Land Mobile Network Identifier
- P-CSCF: Proxy Call Session Control Function
- P-Asserted-Identity: P-Asserted-Identity Header (RFC 3325)
- PFCP: Packet Forwarding Control Protocol
- PCF: Policy Control Function
- PDU Session Modification: PDU Session Modification Procedure
- P-CSCF Discovery: Proxy-CSCF Discovery
- PBX Toll Fraud: PBX Hacking / Toll Fraud
- PQC Migration: Post-Quantum Cryptography Migration
Q
R
- RADIUS: Remote Authentication Dial In User Service
- RAN: Radio Access Network
- Red Team
- Revenue Assurance
- RF: Radio Frequency
- RFID: Radio Frequency Identification
- Roaming
- Roaming Interconnect Security
- Roaming Security Assessment
- Roaming Security Architecture
- Robocalling
- Rogue Base Station (Fake BTS)
- RRH: Remote Radio Head
- RPKI: Resource Public Key Infrastructure
- RSA: Rivest-Shamir-Adleman
- RTP: Real-time Transport Protocol
- RTSP: Real Time Streaming Protocol
- Red Team Exercise
- Risk Assessment
- RIC: RAN Intelligent Controller
- rApp
- Refile Fraud
- RCS: Rich Communication Services
- Revenue Share Fraud: International Revenue Share Fraud (IRSF Model)
- Refile: Interconnect Refile
- RSP: Remote SIM Provisioning
- RANAP: Radio Access Network Application Part
- ROA: Route Origin Authorization
- RPKI-to-Router: RPKI-to-Router Protocol (RTR)
- Registration Update (5G): Mobility/Periodic Registration Update
- Rx Interface: Rx Diameter Reference Point
- Rf / Ro: Diameter Charging Reference Points
S
- SAS: GSMA Security Accreditation Scheme
- SBAS: Satellite-Based Augmentation System
- SC: Signaling Connection
- SCADA: Supervisory Control and Data Acquisition
- SCN: Service Creation Node
- SDSL: Symmetric Digital Subscriber Line
- SECA: Security Administration
- SEPP: Security Edge Protection Proxy
- Service-Based Architecture (SBA) Security
- SGSN: Serving GPRS Support Node
- SHA: Secure Hash Algorithm
- SHR: Shared Resource
- Signaling Firewall
- Signaling IDS
- Signaling Penetration Testing
- Signaling Screening
- SID: Service Identifier
- SIM: Subscriber Identity Module
- SIMBox Fraud
- Silent SMS
- SIP: Session Initiation Protocol
- SIR: Signal-to-Interference Ratio
- SIRT: Security Incident Response Team
- SLA: Service Level Agreement
- SLI: Service Level Indicator
- Slice Isolation (5G)
- Slice Security
- SM: Session Manager
- SMF: Session Management Function
- SMPP: Short Message Peer-to-Peer
- SMS: Short Message Service
- SMS Home Routing
- SMS Pumping
- SMS Spoofing (Interconnect)
- SMSC: Short Message Service Center
- SNMP: Simple Network Management Protocol
- SNR: Signal-to-Noise Ratio
- SOC: Security Operations Center
- Spam
- SRI: Send Routing Information
- SS7: Signaling System No. 7
- SS7 Interconnect Security
- SSID: Service Set Identifier
- SSH: Secure Shell
- SSL: Secure Sockets Layer (deprecated)
- STIR: Secure Telephone Identity Revisited
- Subnet
- Subscriber
- SUCI: Subscription Concealed Identifier
- SUPI: Subscription Permanent Identifier
- SIM Swap
- SOAR: Security Orchestration, Automation and Response
- SBOM: Software Bill of Materials
- SCP Abuse
- SBA Token Forgery
- Slice Hopping
- Smishing
- SECAM: Security Assurance Methodology
- SCP: Service Communication Proxy
- SUPI Concealment
- SMO: Service Management and Orchestration
- SUPI Catcher
- SS7 Message Categories
- SMSC Hijacking
- Subscription Fraud
- Sigma Rules
- Suricata
- Sinkhole
- SEAL: Service Enabler Architecture Layer
- SBA: Service-Based Architecture
- SBI: Service-Based Interface
- S-NSSAI: Single Network Slice Selection Assistance Information
- S-CSCF: Serving Call Session Control Function
- Session Border Controller (SBC): Session Border Controller
- SRVCC: Single Radio Voice Call Continuity
- SRTP: Secure Real-time Transport Protocol
- SIM Box: SIM Box (GSM Gateway)
- STIR/SHAKEN: Secure Telephone Identity Revisited / Signature-based Handling of Asserted information using toKENs
- SM-DP+: Subscription Manager Data Preparation Plus
- SM-SR: Subscription Manager Secure Routing
- S1AP: S1 Application Protocol
- SEAF: SEcurity Anchor Function
- Satellite Backhaul: Satellite Transport Backhaul
- Segment Routing: Segment Routing (SR)
- SRv6: Segment Routing over IPv6
- Service Request (5G): 5G Service Request Procedure
- SIP Digest: SIP Digest Authentication
- SLH-DSA: Stateless Hash-Based Digital Signature Algorithm (FIPS 205)
- SEPP Security: Security Edge Protection Proxy Security
T
- TAC: Terminal Access Controller
- TAP: Telecommunications Analysis Service
- TCP: Transmission Control Protocol
- TCP/IP
- TCAP: Transaction Capabilities Application Part
- TCAP Abuse
- TDD: Time Division Duplex
- TDMA: Time Division Multiple Access
- TEID: Tunnel Endpoint Identifier
- Telecom: Telecommunications
- Telecom Attack Surface Mapping
- Telecom Penetration Testing
- Telecom SIEM
- Telnet
- TETRAPOL
- Threat Intelligence: Telecom-Specific
- Threat-Led Assessment
- TLS: Transport Layer Security
- TM Forum: TeleManagement Forum
- TM Forum Open APIs
- TMSI: Temporary Mobile Subscriber Identity
- TMSI Reallocation
- Toll Bypass
- Toll Fraud
- TPS: Telecom Policy Service
- TR-069: CPE WAN Management Protocol
- Traffic Baselining
- Traffic Engineering
- Transcoding
- Trunk
- TTC: Telephone Terminal Channel
- TTL: Time To Live
- Threat Hunting (Telecom)
- Threat Modeling
- Tabletop Exercise
- Telecom Forensics
- Telecom Reconnaissance
- TNGF: Trusted Non-3GPP Gateway Function
- Torpedo Attack
- Telecom Honeypot
- TM Forum ODA: Open Digital Architecture
- TrGW: Transition Gateway
- Third-Party Registration: SIP Third-Party REGISTER
- Traffic Pumping: Access Stimulation / Traffic Pumping
- TSN: Time-Sensitive Networking
- TSC: Time-Sensitive Communications
- TLS 1.3: Transport Layer Security 1.3
U
- UDP: User Datagram Protocol
- UDM: Unified Data Management
- UEA: User Equipment Algorithm
- UMTS: Universal Mobile Telecommunications System
- USIM: Universal Subscriber Identity Module
- UPF: User Plane Function
- User Plane Security
- UDR: Unified Data Repository
- UDSF: Unstructured Data Storage Function
- UEBA: User and Entity Behavior Analytics
- URSP: UE Route Selection Policy
- URLLC: Ultra-Reliable Low-Latency Communications
- UE Policy: UE Policy Delivery (5G)
V
- VDSL: Very High Speed Digital Subscriber Line
- VLR: Visitor Location Register
- VLAN: Virtual Local Area Network
- VoIP: Voice over IP
- VoLTE: Voice over LTE
- VPN: Virtual Private Network
- VRAN: Virtual Radio Access Network
- vSIM: Virtual SIM
- Vulnerability Assessment
- Vulnerability Management
- Vishing
- VoNR: Voice over New Radio
- VoWiFi: Voice over Wi-Fi
W
- Wangiri Fraud
- WAN: Wide Area Network
- WCDMA: Wideband Code Division Multiple Access
- WPA: Wi-Fi Protected Access
- WPA2: Wi-Fi Protected Access 2
- WPA3: Wi-Fi Protected Access 3
- WEP: Wired Equivalent Privacy
- Wangiri: One-Ring Callback Fraud
- WireGuard: WireGuard VPN Protocol
- Wangiri 2.0: Wangiri 2.0 (Web-Initiated Callback Fraud)
X
- X.25
- X.500
- X.509
- xDSL: Generic DSL
- XMPP: Extensible Messaging and Presence Protocol
- XDR: Extended Detection and Response
- xApp
- Xn Interface
- XnAP: Xn Application Protocol
- X1: Lawful Interception X1 Interface (ETSI TS 103 221-1)
- X2 (LI): Lawful Interception X2 Interface — Intercept Related Information
- X3 (LI): Lawful Interception X3 Interface — Content of Communication
- Xn Handover: Xn-based Handover