This glossary is probably mostly complete. In some cases, it may reference the list of Objectives, but only reference one spot where the topic is mentioned by the list of objectives. Fortunately, the Guide for CompTIA Network+ (N10-005) has quite a bit of cross-referencing, so if there are multiple objectives related to a topic, that guide may point that out.

Some of these terms in this glossary and/or the objectives feel a bit more appropriate for other exams (logic bomb for Security+, ESD / USB for A+). Still, they have been listed, so presumably they may show up on a Network+ certification exam.

Glossary from CompTIA Network+ N10-005

Note: This includes the terms from the glossary. Additional definitions, references, and/or commentary may be derived independently, and were not created by CompTIA. Individual definitions may not have been individually approved by CompTIA.

The latter pages on the Objectives document lists a glossary with several terms.

AAA

“Authentication Authorization and Accounting” (according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: Glossary: AAA (Security)

ACL

“Access Control List” (according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: Glossary: ACL

ADSL

“Asymmetric Digital Subscriber Line” (according to CompTIA's N10-005 objectives).

Asymmetric DSL: A DSL (“high speed” Internet connection by phone companies) where the upload speed may be different (typically slower) than the download speed. For further details, see: CompTIA Network+ N10-005 Certification Exam Objectives section 3.4: subsection related to DSL.

AES

“Advanced Encryption Standard” (according to a document providing CompTIA's N10-005 Certification Exam Objectives).

AH

“Authentication Header” (according to a document providing CompTIA's N10-005 Certification Exam Objectives).

Check out: IPSec, Wikipedia's page on IPSec: “Authentication Header” section.

AM

“Amplitude Modulation” (according to a document providing CompTIA's N10-005 Certification Exam Objectives).

Modulating (changing) the amplitude of a wireless signal. Amplitude refers to how high and low the wavelength is. Other variations are Frequency Modulation and Phase Modulation. This has been quite famous due to radio stations broadcasting using AM as a method of transmitting a signal.

APIPA

“Automatic Private Internet Protocol Addressing” (according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: N10-005 section 1.3: subsection about APIPA.

ARIN

“American Registry for Internet Numbers” (according to a document providing CompTIA's N10-005 Certification Exam Objectives).

This is the RIR that handles the USA, Canada, and Antarctica. See: Glossary: Regional Internet Registry.

ARP

“Address Resolution Protocol” (according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: ARP protocol.

ASP

“Application Service Provider”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

(Note: Also often: “Active Server Page”.)

ATM

“Asynchronous Transfer Mode”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

Note: Also “automatic teller machine”: refers to machines that provide some banking services (especially allowing people to withdraw money).

See: N10-005 section 3.4: ATMs.

BERT

“Bit-Error Rate Test”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

BGP

“Border Gateway Protocol”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

BNC

“British Naval Connector / Bayonet Niell-Concelman”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: N10-005 section 3.2: subsection about BNC

BootP

“Boot Protocol /Bootstrap Protocol”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: BOOTP, perhaps most well known for ports used by BOOTP.

BPDU

“Bridge Protocol Data Unit”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

BRI

“Basic Rate Interface”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

Perhaps contrasted with PRI?

CARP

“Common Address Redundancy Protocol”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: N10-005 Certification section 4.6: subsection about CARP.

CHAP

“Challenge Handshake Authentication Protocol”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

CIDR

“Classless inter domain routing”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

Perhaps more frequently cited as “classless inter-domain routing” (with a hyphen).

First, see: section 1.3: subnetting, and then see the earlier section 1.3: CIDR.

CNAME

“Canonical Name”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

CRAM-MD5

“Challenge-Response Authentication Mechanism ? Message Digest 5”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

CSMA / CA

“Carrier Sense Multiple Access / Collision Avoidance”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: Glossary: CSMA (and specifically the subsection about CSMA/CA).

CSMA / CD

“Carrier Sense Multiple Access / Collision Detection”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: Glossary: CSMA (and specifically the subsection about CSMA/CA).

CSU

“Channel Service Unit”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See section 3.8: subsection about CSU/DSU.

dB

“decibels”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: Glossary: decibel. For the CompTIA Network+, also see: dB loss.

DHCP

“Dynamic Host Configuration Protocol”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

DLC

“Data Link Control”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

(Players of video games, who may be used to enhancements being obtained from the Internet, may be familiar with this abbreviation standing for something different: “downloadable content”.)

DMZ

“Demilitarized Zone”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

N10-005 section 5.5 subsection on DMZ

DNS

“Domain Name Service / Domain Name Server / Domain Name System”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: DNS or, more generally, name resolution. For the CompTIA Network+, see section 1.5 subsection on DNS and Section 1.7 (DNS).

DOCSIS

“Data-Over-Cable Service Interface Specification”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

As the name suggests, this is related to the type of Internet service provided by companies that may be famous for their service of providing “cable TV” programming. Briefly mentioned by section on Networking (discussing IPv6 support).

DoS

“Denial of Service”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

Note that the “o” is lowercase. See: Glossary: DoS.

DDoS

“Distributed Denial of Service”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

Note that the “o” is lowercase. See: Glossary: DDoS.

DSL

“Digital Subscriber Line”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See Glossary: DSL. See also: section 3.4: subsection about DSL.

DSU

“Data Service Unit”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See section 3.8: subsection about CSU/DSU.

DWDM

“Dense Wavelength Division Multiplexing”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: section 3.4: DWDM.

E1

“E-Carrier Level 1”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See also: section 3.4 subsection on T1/E1. Also see: section 3.4 subsection on T3/E3. Also note that there is also a successor called “E3” (unrelated to the Electronic Entertainment Expo).

For similar topics, see: OCx, T1/E1, T3/E3, DS3.

EAP

“Extensible Authentication Protocol”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

EDNS

“Extension Mechanisms for DNS”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: EDNS.

EGP

“Exterior Gateway Protocol”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: section 1.4: subsection about IGP and EGP.

EIGRP

“Enhanced Interior Gateway Routing Protocol”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

EMI

“Electromagnetic Interference”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

section 3.6: subsection about EMI. Also, even though the term doesn't show up in the glossary, be familiar with section 3.6: subsection about cross-talk.

ESD

“Electrostatic Discharge”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

ESSID

“Extended Service Set Identifier”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

ESP

“Encapsulated security packets”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

(Related to IPSec)

FDDI

“Fiber Distributed Data Interface”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

FDM

“Frequency Division Multiplexing”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

FHSS

“Frequency Hopping Spread Spectrum”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

(Related to wireless communication; perhaps 802.11a uses this?)

FM

“Frequency Modulation”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

Modulating (changing) the frequency of a wireless signal. Frequency refers to how many times a wavelength cycles within a certain standard period of time (such as a second). Other variations are Amplitude Modulation and Phase Modulation. This has been quite famous due to radio stations broadcasting using FM as a method of transmitting a signal.

FQDN

“Fully Qualified Domain Name / Fully Qualified Distinguished Name”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

Really, the term more commonly refers to “Fully Qualified Domain Name” (assuming that DNS is worked with more frequently than LDAP).

A entire domain name, including the TLD (“top level domain” like “.com.”) and which ends with the period after the TLD. Domains usually contain an optional period after the TLD (which is usually omitted except when setting up DNS configurations).

FTP

“File Transfer Protocol”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: N10-005 section 1.5 subsection about FTP.

GBIC

“Gigabit Interface Converter”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

Gbps

“Giga bits per second ”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

In networking, this often actually refers to gbps (billions of bits per second), rather than using traditional gigabytes that are 2^{^30} bits in size.

GPG

“GNU Privacy Guard”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

HDLC

“High-Level Data Link Control”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

HSRP

“Hot Standby Router Protocol”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: HSRP

HTTP

“Hypertext Transfer Protocol”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: N10-005 section 1.5: subsection about HTTP.

HTTPS

“Hypertext Transfer Protocol Secure”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: N10-005 section 1.5: subsection about HTTPS.

Hz

“Hertz”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: Glossary: Hertz.

IANA

“Internet Assigned Numbers Authority”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: Glossary: IANA

ICA

“Independent Computer Architecture”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: N10-005 section 5.2 subsection about ICA.

ICANN

“Internet Corporation for Assigned Names and Numbers”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

Basically, in charge of DNS names, and also is the parent organization of IANA (which handles numbers).

ICMP

“Internet Control Message Protocol”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

Perhaps see: the ping command and referenced material. Although, there are other uses for ICMP, such as what is mentioned in the section about the MTU black hole. The firewall page may also currently discuss ICMP. ICMPv6 (for IPv6) is used more than ICMP in IPv4, perhaps most notable because ICMPv6 is used by NDP and MLD.

ICS

“Internet Connection Sharing”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

First supported by Win98SE, this allows a home computer to act as a router (probably by providing NAT).

IDF

“Intermediate Distribution Frame”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: N10-005 section 3.8: subsection on IDF.

IDS

“Intrusion Detection System”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: N10-005 section 5.6: subsection on IDS and IPS.

IEEE

“Institute of Electrical and Electronics Engineers”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

Glossary: IEEE

IGMP

“Internet Group Multicast Protocol”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

section 1.6: IGMP

IGP

“Interior Gateway Protocol”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: section 1.4: subsection about IGP and EGP.

IIS

“Internet Information Services”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

This is the name that Microsoft has given to its web server. See: Microsoft IIS.

IKE

“Internet Key Exchange”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

IMAP4

“Internet Message Access Protocol version 4”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: section 1.5: IMAP. (Know that the only common version of IMAP is IMAP4.)

InterNIC

“Internet Network Information Center”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

IP

“Internet Protocol”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

There are two variations of note: IPv6 and IPv4

See: section 1.2: subsection about IP.

IPS

“Intrusion Prevention System”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: N10-005 section 5.6: subsection on IDS and IPS.

IPSec

“Internet Protocol Security”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

A suite of protocol. Consists of AH and ESP.

section 5.2 (Tunneling and Encryption): subsection about IPSec

IPv4

“Internet Protocol version 4”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

IPv6

“Internet Protocol version 6”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

ISAKMP

“Internet Security Association and Key Management Protocol”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

ISDN

“Integrated Services Digital Network”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: ISDN.

ISP

“Internet Service Provider”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

Glossary: ISP

IT

“Information Technology”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

This simply means “information and technology”, and often refers to technology related to handling information.

IV

“Initialization Vector”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

Kbps

“Kilobits per second”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

Although, when dealing with networking equipment, this might often really be referring to kbps (thousands of bits per second), not kibibits (unambiguously 1,024 bits per second). (This may be discussed by section 1.4: MTU and bandwidth.)

L2F

“Layer 2 Forwarding”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

L2TP

“Layer 2 Tunneling Protocol”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

LACP

“Link aggregation control protocol”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

LAN

“Local Area Network”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: Glossary: LAN.

LC

“Local Connector”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

(See fiber connectors: section 3.2: subsection about fiber connectors)

LDAP

“Lightweight Directory Access Protocol”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

A method of keeping track of data. LDAP is considered to be fairly “lightweight”, and there are multiple implementations. These different implementations are (at least mostly) compatible with each other. An example of an implementation that does, or can (perhaps through exporting/converting) use LDAP is Microsoft's Active Directory.

A bunch of documents related to LDAP standards exist. This is covered a bit by Glossary entry for LDAP.

LEC

“Local Exchange Carrier”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

LED

“Light Emitting Diode”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

In general concept, it is like a light bulb. However, compared to traditional bulbs, they tend to use much less electricity. They may also put out “better” (brighter and/or “cleaner”) light.

LLC

“Logical Link Control”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

A sublayer of Layer 2 of the OSI Model, which is the Data Link Layer. (See: OSI model.)

Note: In business, LLC may stand for “Limited Liability Corporation”. That would be a more common use of the acronym.

MAC

“Media Access Control / Medium Access Control”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

The acronym also expands to “Mandatory Access Control”. See Glosasry entry for MAC. Media Access Control is the lower sublayer of the OSI Model, and is also what “MAC” means when using the term “MAC address”. Definitely be familiar with Media Access Control.

Mbps

“Megabits per second”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

Although, when dealing with networking equipment, this might often really be referring to mbps (millions of bits per second), not mebibits (unambiguously 1,024 bits per second). (This may be discussed by section 1.4: MTU and bandwidth.)

MBps

“Megabytes per second”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

Seems CompTIA really wants people to realize that MBps is different than Mbps. The phrase Mbps refers to bits, not bytes. MBps refers to bytes. (Whether Mega refers to one million or 1024 squared is... perhaps less clear. This may be discussed by section 1.4: MTU and bandwidth.)

MDF

“Main Distribution Frame”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: N10-005 section 3.8: subsection on MDF.

MDI

“Media Dependent Interface”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

MDIX

“Media Dependent Interface Crossover”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

Perhaps a more clear (intermediate) expansion of that acronym would be “MDI with Crossover”. See: crossover cable, auto-MDIX

MIB

“Management Information Base”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

MMF

“Multimode Fiber”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: N10-005 section 3.1 multimode fiber. Perhaps also see: section 3.1: fiber, section 3.1: media converters, section 3.2: fiber connectors

MPLS

“Multi-Protocol Label Switching”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: section 3.5: subsection related to MPLS.

MS-CHAP

“Microsoft Challenge Handshake Authentication Protocol”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

MT-RJ

“Mechanical Transfer-Registered Jack”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: section 3.2 MTRJ. (In the objectives, no hyphen is shown. In the glossary, a hyphen is shown.)

MX

“Mail Exchanger”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

This is refering to DNS. See DNS types.

NAC

“Network Access Control”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: section 5.3: NAC

NaaS

“Network as a Service”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

NAS

“Network Attached Storage”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

A system which stores data, and then shares that data over the network. Unlike a SAN, which essentially makes the device available, a NAS more commonly uses protocols that share files and folders. Perhaps see: filesystems provided over networking, transfering files

NAT

“Network Address Translation”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

Glossary: Network Address Translation, section 2.1: NAT.

NCP

“Network Control Protocol”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

NetBEUI

“Network Basic Input / Output Extended User Interface” (according to a document providing CompTIA's N10-005 Certification Exam Objectives). Actually, the abbreviation is supposed to stand for “NetBIOS Extended User Interface” (where NetBIOS basically stands for “Netowrk Basic Input/Output System”).

This is pronounced as “net boo eee”. (The last two syllables are like the word buoy, which is also not spelled close to how it is pronounced.)

A protocol that was easier to setup than IP as it was rather auto-configured (similar to the automatic address assignment used for link-local addresses). However, like link-local addresses, it was not routable.

NetBIOS

“Network Basic Input / Output System”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

ghacks.net: 2022-Apr-23 article: Microsoft starts to phase out NetBIOS and LLMNR to focus on mDNS” indicates that such network communications may be less prominent in the future. Still, for a trip down memory lane (for some people's memories), compatibility with computers using code that a lot of people may consider historic, or studying content related to the old 10-005 version of the CompTIA Network+ certification, here are some further details:

NetBIOS is a term used by a group of related software/protocol standards that were frequently compatible with other NetBIOS-compatible protocols. These include:

NetBEUI: NetBEUI: A protocol that relied on Layer 2 protocol like Ethernet, just as IPv4 does. However, it was even easier to set up, as it was often completely automatic (similar to using DHCP/IPv4 but without requiring any sort of setup of a DHCP/IPv4 server.) However, like link-local addresses, this protocol was not routable. This basically means that computers within a link, using switches, could communicate with each other well, but it was not designed to work well with larger numbers of computers and did not support the idea of sending traffic through a router to support a different group of computers (comparable to an IPv4 subnet).
NBNS: NetBIOS Name Services: NBNS: NatBIOS Name Services, similar in concept to how DNS is often used to translate names into IP addresses, this helped convert a “NetBIOS Name” into an address that could be used by another protocol like NetBEUI. (This is mentioned by ][CyberPillar][ section about NBNS, a sub-section on the more general topic of ][CyberPillar][ section describing “NetBIOS Names”.)
WINS: Microsoft's created an protocol based on NetBIOS Name Services, designed this protocool for Microsoft Windows and named it “Windows Internet Naming Service” (“WINS&rqduo;. Some people are probably more likely to have seen the name WINS more often than the more generic term of NBNS. “Windows Internet Naming Service” is a technical improvement over NBNS because “Windows Internet Naming Service” violates the “NBNS” standard by not sending some traffic that is not actually required to make things work, but which is required by the “NBNS” specification. (This is also mentioned at: ][CyberPillar][ section describing NBNS.)
NBT: NetBIOS over TCP/IP: NBT implements some NetBIOS functionality (perhaps NBNS?) in environments (operating systems on computers) that implement TCP (or, perhaps more specifically, TCP/IP), which can work even if no NetBEUI support is available. Some Microsoft Windows operating systems don't have NetBEUI support, but some software that was designed to work with some NetBIOS features (probably NBNS) could work when NBT was available. (If memory recalls, Windows 2000 was like that.)

NFS

“Network File Service”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

A remote filesystem used by Unix and similar/compatible operating systems. See: NFS. (That information may currently be quite sparse.)

NIC

“Network Interface Card”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: Glossary: NIC, section 1.2: NIC.

NIPS

“Network Intrusion Prevention System”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: section 5.6 subsection about IDS and IPS. (The text for this section describes NIPS.)

nm

“Nanometer”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

a billionth of a meter. Yeah, that's a millionth of a millimeter. It's pretty small. Hypertextbook: Diameter of a Human Hair notes measurements (from 17 to 181) in micrometers. There are a thousand nanometers in each micrometer.

NNTP

“Network News Transport Protocol”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

Used to distribute Usenet newsgroups. These “newsgroups” were similar in nature to the “bulletin boards” from old “bulletin board systems”, and are roughly analogous to newer web-based “forums”. The big difference is that modern web forums tend to require authentication to post. Usenet was publicly postable, and eventually the unmoderated public newsgroups tended to be overrun by spam.

NTP

“Network Time Protocol”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: section 1.6: NTP

NWLINK

“Microsoft IPX/SPX Protocol”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

Well, actually, IPX/SPX was Novell's protocol. NWLink is a name that Microsoft game to their implementation. NWLink was code that ran under Windows and was designed to let the Windows machine be a client that was able to communicate to a computer using Novell's IPX protocol. This was bundled with (and perhaps installed, by default) some versions of Microsoft Windows. Novell did release their own version of a Netware client for Windows, so Novell's own software could be used to perform these communications.

As IPX/SPX is not routable, it has been abandoned (even by Novell). It is a bit surprising that CompTIA Network+ even lists this in the glossary.

OCx

“Optical Carrier”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: OCx, T1/E1, T3/E3, DS3.

OS

“Operating Systems”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: operating systems.

OSI

“Open Systems Interconnect”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

Creators of the OSI Model. See: section 1.1.

OSPF

“Open Shortest Path First”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: section 1.4: OSPF. Perhaps also about half of the other topics in: section 1.4 may have information related to properties of routing protocols. Some versions of RAS may support some version(s) of this routing protocol. (See section 5.2 subsection on RAS).

network traffic routing protocols (currently has very minimal information, and may have no details about this specific protocol).

OTDR

“Optical Time Domain Reflectometer”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: N10-005 section 4.2: subsection for OTDR.

PAP

“Password Authentication Protocol”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

...

PAT

“Port Address Translation”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: N10-005 section 2.1: subsection about PAT.

PC

“Personal Computer”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

Historically these often had less power (less powerful CPU, memory) than a business workstation, except when heavily invested in (as often happened by people wanting to play games). They may be more likely to have a consumer-based operating system, rather than a server-based operating system.

PGP

“Pretty Good Privacy”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

Software designed to encrypt data (possibly specifically E-Mailed data?). On a side note, “GNU Privacy Guard”, also known as “GnuPG” or “GPG”, is an open source piece of software which performs the same sort of task.

PKI

“Public Key Infrastructure”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

A centralized “certificate authority” can verify the legitimacy of a private key. The private key can be used to send messages to people who have a matching public key. With those messages authenticated, the possessor of the public key can be assured, and can then use the public key to send a message that only the older of the private key can understand.

This whole trust system can also mark a key as invalid when the certificate authority rejects the key.

PoE

“Power over Ethernet”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

POP3

“Post Office Protocol version 3”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: N10-005 section 1.6: POP3.

POTS

“Plain Old Telephone System”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: section 3.4 subsection on dial-up

PPP

“Point-to-Point Protocol”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

(Written off top of head... may need verification...) Capable of encapulating other data and handling logins and negotiation of commonly supported connection options. This has been quite useful when trying to support remote users through some sort of encapsulation process. So useful, in fact, that other protocols (PPTP, PPPoE) have been derived from this standard.

PPPoE

“Point-to-Point Protocol over Ethernet”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

This is sometimes used for authentication, allowing a device like a DSL modem to authenticate to an ISP. Users may need to put mandatory settings into a device in order for the Internet connection to be fully operational.

PPTP

“Point-to-Point Tunneling Protocol”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

Based on PPP.

PRI

“Primary Rate Interface”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

Perhaps contrasted with BRI?

PSTN

“Public Switched Telephone Network”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: section 3.4 subsection on dial-up

PVC

“Permanent Virtual Circuit”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

May also refer to “polyvinyl chloride”, which is a type of covering that might surround some Ethernet cabling.

QoS

“Quality of Service”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: section 4.6: QoS, section 2.1 subsection on QoS.

RADIUS

“Remote Authentication Dial-In User Service”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

section 5.3: RADIUS.

RARP

“Reverse Address Resolution Protocol”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: RARP. This is different from Inverse ARP. (Perhaps see: section 1.6: ARP.)

RAS

“Remote Access Service”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

section 5.2: RAS.

RDP

“Remote Desktop Protocol”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

(This may benefit from some verification, but the following is believed to be true... Most well known for RDC, although RDP may also be used by other software that controls computers (most famously might be MMC snap-ins, such as “Computer Management”, or their non-MMC equivilents. Often they use RDP.)

See: section 5.2: RDP, section 1.5: RDP

RFI

“Radio Frequency Interface”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

RG

“Radio Guide”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

RIP

“Routing Internet Protocol”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: section 1.4: RIP

“Open Shortest Path First”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

network traffic routing protocols (currently has very minimal information, and may have no details about this specific protocol).

RJ

“Registered Jack”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

Computer technicians wanting to be ready for the CompTIA Network+ certification examination should be familiar with RJ45. Perhaps also be familiar with RJ11.

RSA

“Rivest, Shamir, Adelman”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

A team of three people who have created the RSA security standard. A digital key can be of the type known as RSA, or DSA.

RSH

“Remote Shell”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: Remote Access: RSH.

RTP

“Real Time Protocol”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: section 1.6: subsection about “RTP (VoIP)”.

RTSP

“Real Time Streaming Protocol”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

Effectively replacing HTTP as the primary protocol overseeing the task of getting data from a server to a client. Used by some media programs. Standardized by RFC 2326: “Real Time Streaming Protocol (RTSP)”. The first paragraph of Wikipedia's article on RTSP: “Protocol directives” section summarizes nicely: “While similar in some ways to HTTP, RTSP defines control sequences useful in controlling multimedia playback. While HTTP is stateless, RTSP has state; an identifier is used when needed to track concurrent sessions. Like HTTP, RTSP uses TCP to maintain an end-to-end connection and, while most RTSP control messages are sent by the client to the server, some commands travel in the other direction (i.e. from server to client).”

Just because an RFC was published for RTSP does not mean that connections using RTSP are transferring data using wide-open standards. An earlier paragraph from Wikipedia's article for RTSP notes, “The transmission of streaming data itself is not a task of the RTSP protocol. Most RTSP servers use the Real-time Transport Protocol (RTP) in conjunction with Real-time Control Protocol (RTCP) for media stream delivery, however some vendors implement proprietary transport protocols. The RTSP server from RealNetworks, for example, also features RealNetworks' proprietary Real Data Transport (RDT).”

RTT

“Round Trip Time or Real Transfer Time”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

SA

“Security Association”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

SC

“Standard Connector / Subscriber Connector”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

(See fiber connectors: section 3.2: subsection about fiber connectors).

SCP

“Secure Copy Protocol”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: SCP. One thing to note is that it uses the same port number as SSH.

SDSL

“Symmetrical Digital Subscriber Line”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

This gets mentioned by section 3.4: subsection about DSL.

SFTP

“Secure File Transfer Protocol”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

SFTP, as well as other information from Secure standars with “FTP” as part of the name.

SFP

“Small Form-factor Pluggable”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: section 3.2: connectors: subsection about fiber: note made about SFP.

SIP

“Session Initiation Protocol”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

SLIP

“Serial Line Internet Protocol”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

Used around the 1990's for reasons similar to PPP. Might be generally considered obsolete by this time?

SMF

“Single Mode Fiber”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

section 3.1: subsection about Single Mode Fiber.

SMTP

“Simple Mail Transfer Protocol”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: section 1.5: subsection about SMTP

SNAT

“Static Network Address Translation”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

Generally refers to having a set of addresses that correspond to another set of addresses, and then NAT occurs. The NAT makes traffic from or to one address get treated as if a different address was used instead. (See also: NAT.)

SNMP

“Simple Network Management Protocol”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: section 1.6: subscection about SNMP and the various sections under section 4.4.

SNTP

“Simple Network Time Protocol”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: section 1.6: subsection about NTP.

SOA

“Start of Authority”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

This is refering to DNS. See DNS types.

SOHO

“Small Office / Home Office”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

Small offices, similar to the size of businesses that are sometimes run out of people's homes.

A section of the exam objectives deals with SOHO. See: section 2.6: SOHO.

SONET

“Synchronous Optical Network”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: section 3.4: subsection about SONET and also section 3.4: subsection about SDH.

SPS

“Standby Power Supply”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

SSH

“Secure Shell”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: section 1.5: scection about SSH.

SSID

“Service Set Identifier”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

Mentioned by: section 2.2: subsection related to SSID, section 2.4: subsection about SSID mismatch. Perhaps see also: section 2.4: Configurations.

SSL

“Secure Sockets Layer”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

Perhaps see: section 1.6: subsection about TLS, section 5.2: subsection about SSL VPN. Also, section 1.5: subsection about HTTPS utilizes SSL. See also: TLS.

ST

“Straight Tip or Snap Twist”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

(See fiber connectors: section 3.2: subsection about fiber connectors)

STP

“Shielded Twisted Pair”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

The section on Shielded Twisted Pair mentions some of the other meanings that “STP” may refer to.

Perhaps see also: shielded twisted pair.

T1

“T-Carrier Level 1”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See section 3.4 subsection on T1/E1. Also see: section 3.4 subsection on T3/E3. Also note that there is also a successor called “T3”.

For similar topics, see: OCx, T1/E1, T3/E3, DS3.

TA

“Terminal Adaptor”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

TACACS+

“Terminal Access Control Access Control System+”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: section 5.3: note on TACACS+.

TCP

“Transmission Control Protocol”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

section 1.6: subsection about TCP.

TCP / IP

“Transmission Control Protocol / Internet Protocol”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

Generally written out as “TCP/IP” (without spaces surrounding the slashes).

This may refer to using TCP as well as IP, or it may be referring to the title of the protocol suite. Another possibility, of what this term may refer to, may be the TCP/IP Model.

TDM

“Time Division Multiplexing”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

TDR

“Time Domain Reflectometer”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

Telco

“Telephone Company”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

Historically supplying telephone service, these companies now provide Internet access using technologies such as DSL and ISDN.

TFTP

“Trivial File Transfer Protocol”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: section 1.6: subsection about TFTP.

TKIP

“Temporal Key Integrity Protocol”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

TLS

“Transport Layer Security”(according to a document providing CompTIA's N10-005 Certification Exam Objectives).

See: section 1.6: subsection about TLS, section 5.2: subsection about tunneling with TLS, and a different section 5.2: subsection about tunneling with TLS.