Language

Glossary

Search by full name or abbreviation (Ctrl K). First-use expansions also appear inside the notes.

TCP — Transmission Control Protocol: Transport that provides ordered, reliable byte delivery while the connection remains viable. First lesson: L01.
UDP — User Datagram Protocol: Transport that sends datagrams without TCP-style delivery and ordering guarantees. First lesson: L01.
IP — Internet Protocol: Network-layer addressing and delivery to an endpoint. IP protocol numbers such as 50/51 are not TCP/UDP ports. First lesson: L01.
TLS — Transport Layer Security: Protects a session from eavesdropping and tampering and commonly authenticates a server. First lesson: L02.
SSL — Secure Sockets Layer: Obsolete predecessor of TLS. People may still say “SSL certificate.” Not an acceptable modern fallback. First lesson: L02.
HTTPS — Hypertext Transfer Protocol Secure: Web communication protected by TLS. Does not by itself encrypt files saved later to disk. First lesson: L02.
HTTP — Hypertext Transfer Protocol: Web request/response protocol, commonly TCP 80. First lesson: L05.
CA — Certificate Authority: A trusted issuer in a public-key infrastructure. First lesson: L03.
PKI — Public Key Infrastructure: The trust system of certificates, issuers and related key management. First lesson: L03.
NTP — Network Time Protocol: Helps devices agree on time. Commonly UDP 123. Lower stratum means fewer timing steps from the reference, not automatic trust. First lesson: L04.
GPS — Global Positioning System: A possible stratum 0 time reference. Also used in outdoor geofencing. First lesson: L04.
SMB — Server Message Block: File and printer sharing. Modern direct SMB uses TCP 445; legacy SMB over NetBIOS uses TCP 139. First lesson: L05.
NAS — Network Attached Storage: A storage appliance on the network. In authentication lessons NAS can instead mean Network Access Server — use the surrounding subject. First lesson: L05.
HTML — Hypertext Markup Language: One type of web content, not a synonym for HTTP. First lesson: L05.
FTP — File Transfer Protocol: Control commonly TCP 21 plus a separate data connection. Active data traditionally sources from TCP 20; passive data uses a negotiated port. First lesson: L06.
SFTP — SSH File Transfer Protocol: File transfer over SSH, commonly TCP 22. The deck may say Secure File Transfer Protocol as a course alias. Not FTPS. First lesson: L06.
FTPS — FTP over TLS: FTP protected by TLS. Explicit commonly starts on 21; implicit commonly uses 990. Still FTP-style control/data. First lesson: L06.
SSH — Secure Shell: Encrypted remote access, commonly TCP 22. Host keys identify the server. First lesson: L06.
SQL — Structured Query Language: A language used with relational databases. Not a product and not a single port. First lesson: L07.
RDBMS — Relational Database Management System: Organizes related data, usually in tables. First lesson: L07.
VoIP — Voice over Internet Protocol: Turns sound into packets. SIP sets up the call; RTP carries media. First lesson: L08.
SIP — Session Initiation Protocol: Establishes and manages calls, commonly TCP/UDP 5060; SIP over TLS commonly TCP 5061. First lesson: L08.
RTP — Real-time Transport Protocol: Carries voice/video media, normally over negotiated UDP ports. There is no single universal RTP port. First lesson: L08.
RTCP — RTP Control Protocol: Reports reception and quality information for RTP. First lesson: L08.
SRTP — Secure RTP: Protects media. Securing SIP signaling alone does not encrypt every voice packet. First lesson: L08.
PBX — Private Branch Exchange: Office call functions such as extensions, voicemail and queues. First lesson: L08.
VLAN — Virtual Local Area Network: A logical Layer 2 broadcast domain. Creation is switch configuration, not a complete firewall policy. First lesson: L08.
QoS — Quality of Service: Classification, queuing and scheduling. Chooses who goes first; does not create extra physical bandwidth. First lesson: L08.
PoE — Power over Ethernet: Power a device using its network cable. First lesson: L08.
DRP — Disaster Recovery Plan: How to restore technology after disruption. Slide-supported likely match for a note that said DRIP; not certainty about the original shorthand. First lesson: L09.
BCP — Business Continuity Planning: Keeps essential work operating during disruption. First lesson: L09.
BIA — Business Impact Analysis: Identifies what disruption would cost and which functions matter most. First lesson: L09.
ITCP — Information Technology Contingency Planning: Prepares alternative arrangements for IT disruptions. First lesson: L09.
RTO — Recovery Time Objective: Target time to restore a service. First lesson: L10.
RPO — Recovery Point Objective: How far back recoverable data may be — the acceptable data-loss window. First lesson: L10.
WRT — Work Recovery Time: Time to reconcile work after technical restoration. First lesson: L10.
MTD — Maximum Tolerable Downtime: The business limit for being down. First lesson: L10.
MTBF — Mean Time Between Failures: Estimated interval between failures — not a promise for the next device. First lesson: L11.
MTTF — Mean Time to Failure: Estimated time until failure. First lesson: L11.
MTTR — Mean Time to Repair: Estimated repair duration. First lesson: L11.
UPS — Uninterruptible Power Supply: Bridges power loss for equipment. First lesson: L11.
CDN — Content Delivery Network: Distributed edges that serve eligible content closer to users. Scope addition; no dedicated slide located. First lesson: L12.
Nmap — Network Mapper: Host and service discovery tool for authorized examination. First lesson: L13.
SNMP — Simple Network Management Protocol: Manager/agent monitoring. Queries commonly UDP 161; notifications received on UDP 162. First lesson: L14.
MIB — Management Information Base: Describes managed objects — the menu. First lesson: L14.
OID — Object Identifier: Identifies an object in the SNMP naming hierarchy — the item number. First lesson: L14.
SIEM — Security Information and Event Management: Parses, normalizes and correlates logs across sources. First lesson: L15.
DNS — Domain Name System: Resolves names. Commonly UDP/TCP 53. First lesson: L16.
DHCP — Dynamic Host Configuration Protocol: Supplies address settings. Remember DORA. Server UDP 67, client UDP 68. First lesson: L16.
SPAN — Switched Port Analyzer: Port mirroring that copies selected traffic to an observation port. First lesson: L17.
TAP — Test Access Point: Another way to observe a link; capabilities depend on design. First lesson: L17.
IPFIX — Internet Protocol Flow Information Export: Flow-export family related to NetFlow-style summaries. First lesson: L17.
CRC — Cyclic Redundancy Check: Errors can indicate damaged frames or a physical-link problem. First lesson: L18.
CoS — Class of Service: Often Layer 2 priority marking. First lesson: L19.
DiffServ — Differentiated Services: IP-layer markings and policies. First lesson: L19.
CIA — Confidentiality, Integrity and Availability: Security goals, not three products to purchase. First lesson: L20.
PII — Personally Identifiable Information: Information that can identify a person, directly or in combination. Do not confuse with PUE. First lesson: L21.
GDPR — General Data Protection Regulation: European Union personal-data protection framework. First lesson: L21.
PCI DSS — Payment Card Industry Data Security Standard: Payment-card security standard, not a general name for every privacy law. First lesson: L21.
PHI — Protected Health Information: Health-privacy term for identifiable health information in the applicable framework, particularly US HIPAA. Scope addition; no dedicated slide located. First lesson: L22.
HIPAA — Health Insurance Portability and Accountability Act: US health-privacy act name associated with PHI discussion. First lesson: L22.
PUE — Power Usage Effectiveness: Total facility energy divided by IT equipment energy. Not a privacy score and not PII. First lesson: L22.
AES — Advanced Encryption Standard: A symmetric encryption algorithm. First lesson: L23.
RSA — Rivest–Shamir–Adleman: An asymmetric algorithm family. Not how every byte of a modern web session is encrypted. First lesson: L23.
SHA — Secure Hash Algorithm: A family of hash algorithms. First lesson: L23.
MD5 — Message Digest Algorithm 5: Obsolete for collision-resistant security uses. First lesson: L23.
DoS — Denial of Service: Prevents legitimate use by exhausting or disrupting a resource. First lesson: L25.
DDoS — Distributed Denial of Service: Denial of service involving many sources. First lesson: L25.
C2 — Command and Control: Communication used to instruct compromised devices. Also written C&C. Not a synonym for malware. First lesson: L26.
APT — Advanced Persistent Threat: A sustained, capable campaign, not just one executable. First lesson: L26.
AVT — Advanced Volatile Threat: Deck term for volatile/memory-focused threats. First lesson: L26.
LOC — Low-Observable Characteristics: Quiet behavior designed to evade attention. First lesson: L26.
MAC — Media Access Control: Link-layer interface identity. Weak as sole identity proof. First lesson: L27.
ARP — Address Resolution Protocol: Maps local IPv4 addresses to link-layer addresses. Local-link only. First lesson: L27.
DAI — Dynamic ARP Inspection: Validates ARP messages, commonly using DHCP snooping bindings. First lesson: L27.
DORA — Discover, Offer, Request, Acknowledge: Normal IPv4 DHCP exchange order. First lesson: L28.
MFA — Multi-Factor Authentication: Uses different factor categories, not two passwords. First lesson: L30.
OTP — One-Time Password: A code format; factor classification depends on how it is generated and protected. First lesson: L30.
AAA — Authentication, Authorization and Accounting: Proof of identity, permitted actions, and activity records. First lesson: L31.
RADIUS — Remote Authentication Dial-In User Service: Commonly UDP 1812 authentication/authorization and 1813 accounting. First lesson: L31.
TACACS+ — Terminal Access Controller Access-Control System Plus: Commonly TCP 49, often for device administration. First lesson: L31.
SSO — Single Sign-On: Access multiple services without repeatedly logging in. Not a synonym for federation. First lesson: L32.
KDC — Key Distribution Center: Kerberos service including AS and TGS. First lesson: L32.
AS — Authentication Service: Kerberos component involved in initial authentication. First lesson: L32.
TGS — Ticket Granting Service: Issues service tickets after a TGT is held. First lesson: L32.
TGT — Ticket Granting Ticket: Lets a client request service tickets without sending the password to each service. Not the ticket handed to every file server. First lesson: L32.
IdP — Identity Provider: Authenticates the user and issues identity assertions. First lesson: L33.
SP — Service Provider: Relies on validated assertions to establish a session. First lesson: L33.
SAML — Security Assertion Markup Language: A common federation standard for carrying assertions. First lesson: L33.
RBAC — Role-Based Access Control: Permissions follow roles; users are assigned to roles. Not firewall packet filtering. First lesson: L34.
PAM — Privileged Access Management: Protects powerful accounts with extra controls. First lesson: L34.
LDAP — Lightweight Directory Access Protocol: Directory access, commonly TCP 389. Not itself a permission set. First lesson: L35.
DN — Distinguished Name: Uniquely locates a directory entry. First lesson: L35.
LDAPS — LDAP over TLS: Commonly TCP 636. First lesson: L35.
SASL — Simple Authentication and Security Layer: A framework for authentication mechanisms, not a guarantee every bind is encrypted. First lesson: L35.
IEEE 802.1X — IEEE 802.1X: Port-based network access control. A standard, not port 8021. First lesson: L37.
EAP — Extensible Authentication Protocol: Authentication framework; the method determines how identity is proved. First lesson: L37.
EAPOL — EAP over LAN: Runs between supplicant and authenticator. First lesson: L37.
NAC — Network Access Control: Broader policy that may check device condition and restrict a network. First lesson: L37.
ACL — Access Control List: A set of traffic rules. This app’s simulator uses first-match then default deny. First lesson: L38.
URL — Uniform Resource Locator: A locator used in content filtering and web requests. First lesson: L39.
DMZ — Demilitarized Zone: Also called a screened subnet in these slides: a controlled place for public-facing services. First lesson: L40.
IDS — Intrusion Detection System: Observes and alerts. Does not by itself stop traffic. First lesson: L41.
IPS — Intrusion Prevention System: Can intervene, commonly inline. In L43 IPS instead means Indoor Positioning System. First lesson: L41.
NIDS — Network-based IDS: Watches traffic. First lesson: L41.
HIDS — Host-based IDS: Observes activity on one endpoint. First lesson: L41.
IoT — Internet of Things: Connected devices that interact with the physical world. First lesson: L42.
OT — Operational Technology: Monitors or changes physical processes. First lesson: L42.
ICS — Industrial Control Systems: Umbrella for industrial automation/control. Slide-supported likely match for a note that said IDCS. First lesson: L42.
DCS — Distributed Control System: Commonly coordinates processes within a plant or facility. First lesson: L42.
SCADA — Supervisory Control and Data Acquisition: Commonly supervises equipment across remote sites. First lesson: L42.
PLC — Programmable Logic Controller: Controls machine processes. First lesson: L42.
RTU — Remote Terminal Unit: Connects remote field information/control. First lesson: L42.
MTU — Master Terminal Unit: Slide name for a supervisory role in the industrial comparison. Not Ethernet maximum transmission unit in this lesson. First lesson: L42.
CCTV — Closed-Circuit Television: Camera and recording systems that also need passwords, updates and segmentation. First lesson: L43.
PTZ — Pan-Tilt-Zoom: Camera that can change viewing direction and zoom. First lesson: L43.
IPS (physical) — Indoor Positioning System: Indoor location technology on the geofencing slide. Same letters as Intrusion Prevention System. First lesson: L43.
AP — Wireless Access Point: Connects wireless clients to a network. First lesson: L44.
WLC — Wireless Local Area Network Controller: Central management for many APs. Not a general substitute for a router, DHCP server or firewall. First lesson: L44.
SSID — Service Set Identifier: Advertised wireless network name, not proof of trust. First lesson: L44.
LWAPP — Lightweight Access Point Protocol: Older controller/AP protocol. First lesson: L44.
CAPWAP — Control And Provisioning of Wireless Access Points: Standardized controller/AP communication. First lesson: L44.
FTTC — Fiber to the Curb: Fiber near the customer, last part commonly copper/VDSL. First lesson: L45.
FTTP — Fiber to the Premises: Fiber reaches the building. Architecture, not a speed guarantee. First lesson: L45.
VDSL — Very-high-bit-rate Digital Subscriber Line: Common last-segment technology in FTTC designs. First lesson: L45.
OLT — Optical Line Terminal: Provider-side optical equipment. First lesson: L45.
ONT — Optical Network Terminal: Customer-side optical termination. First lesson: L45.
VPN — Virtual Private Network: Logical private connection over another network. Encapsulation is not automatically encryption. First lesson: L46.
GRE — Generic Routing Encapsulation: Course example of a tunnel without built-in confidentiality. First lesson: L46.
PPP — Point-to-Point Protocol: Establishes point-to-point links. Not itself a universal encryption mechanism. First lesson: L46.
IPsec — Internet Protocol Security: Protects IP traffic using negotiated security arrangements. First lesson: L47.
ESP — Encapsulating Security Payload: Can provide confidentiality and integrity. Native ESP is IP protocol 50, not TCP port 50. First lesson: L47.
AH — Authentication Header: Integrity/authentication without encryption. IP protocol 51, not a TCP/UDP port. First lesson: L47.
IKE — Internet Key Exchange: Negotiates security associations and keys. Commonly UDP 500. First lesson: L47.
SA — Security Association: Describes security parameters for traffic. IPsec SAs are directional. First lesson: L47.
NAT-T — Network Address Translation Traversal: Commonly UDP 4500 for IPsec through NAT. First lesson: L47.
RAS — Remote Access Server: Authenticates remote access and applies policy. First lesson: L46.
QUIC — QUIC: The protocol’s name; do not invent a formal expansion. HTTP/3 commonly uses QUIC over UDP 443. First lesson: L01.