Unfamiliar Acronyms Flashcards
(129 cards)
APT
Advanced Persistent Threat / Advanced Persistent Tool
An unauthorized person in a network, undetected, for an exceedingly long period of time. (e.g. Russia in our infrastructure after SolarWinds hack)
ASIC
Application Specific Integrated Circuit
A specialized microchip designed to provide customized features to a specific application.
[Apparently used by Layer 3 Switches]
ASP
Application Service Provider
A business that provides software services (e.g. CRM, credit card processing) over a network (and the Internet) using standard protocol like HTTP. Has generally been replaced by SaaS, and differs from SaaS in the following ways:
- ASPs try to focus on managing and hosting 3rd-party software, while SaaS vendors manage the software they have developed on their own.
- ASPs provide more traditional client-server apps, requiring installation of “thin client” software on users’ PCs. On the other hand, SaaS rely solely on the Web and can be accessed via a web browser.
- ASPs’ software architecture requires that, for each business, whereas SaaS solutions use multi-tenant architecture in which they serves multiple users and businesses.
- ASPs don’t provide the same scalability and cost-saving as SaaS
- ASP is basically a failed model [says one site]
BCP
Business Continuity Plan
A document that details how an organization intends to maintain business operations during a disaster.
i.e. The strategy for addressing potential threats to a company and creation of systems to aid in the prevention of threats and recovery from problems.
BERT
Bit-Error Rate Test
A test to see the percentage of received bits of a data stream that has changed due to noise, interference, or other distortion.
BERT contains both a stress pattern generator (which can generate a variety of bit patterns) and an error detector (which is synchronized with the pattern generator and can determine the number of bit errors).
Unlike many other forms of testing, bit error rate, BER measures the full end to end performance of a system including the transmitter, receiver and the medium between the two.
[Pretty sure this is for Layer 1 testing]
BLE
Bluetooth Low Energy (or Bluetooth LE)
Also called Bluetooth Smart, a new version of Bluetooth that provides a range comparable to the earlier version of Bluetooth, but that consumes less power.
A Bluetooth variant designed for use in IoT networks by battery-powered devices.
BSSID
Basic Service Set Identifier
Identifier for a particular access point within a wireless LAN (WLAN). The MAC address of the AP is used as this identifier.
While an SSID (i.e. network name like ‘Mouse’) is sufficient for a WLAN with only one access point, when a WLAN contains multiple access points, the network needs a way to associate client traffic with a particular AP.
[See also ESSID]
Good overview: https://www.juniper.net/documentation/en_US/junos-space-apps/network-director3.7/topics/concept/wireless-ssid-bssid-essid.html
CaaS
Communication as a Service
A service model in which communication services are provided virtually, such as VoIP or video conferencing.
e.g. Skype, Zoom, FaceTime, Facebook Messenger, Discord, Slack
[Ugh. Apparently also being used for Containers as a Service, like Kubernetes]
[See also DaaS, MaaS, and SECaaS]
CAM
Content Addressable Memory
A special kind of high-speed computer memory optimized for searching (rather than random access) often used in routers and switches for table lookup functions. (e.g. A switch stores its MAC address table in CAM.)
[Remember MAC / CAM related. In fact, MAC table often referred to as CAM table]
Also remember CAM v. RAM]
CARP
Common Address Redundancy Protocol
A protocol that enables multiple hosts on the same network to share a set of IP addresses and thus provides failover redundancy. It is commonly used with routers and firewalls and can provide load balancing.
A redundancy protocol that allows a number of devices to be grouped together to use a single virtual network interface among them.
[Remember Address Redundancy Protocol… but don’t get confused with ARP]
In some cases, you might have a set of IP addresses to share among multiple hosts. For example, if you have multiple routers that support multiple interfaces, and you want to interlace those routers as a fault-tolerant cluster, you would have a list of several IP addresses pointing to the cluster as a group. This is accomplished with CARP (Common Address Redundancy Protocol), which allows a pool of computers or interfaces to share
one or more IP addresses. This pool is known as a group of redundancy or redundancy group. When using CARP, one device, acting as the group master, receives requests for an IP address, then parcels out the requests to one of several devices in the group.
CARP is a free alternative to VRRP (Virtual Router Redundancy Protocol), or Cisco’s propriety version called HSRP (Hot Standby Routing Protocol). Although VRRP and HSRP function somewhat differently than CARP and are used solely for routers, the general idea is the same.
[See also: VRRP and HSRP]
[See also: GLBP]
CHAP
Challenge Handshake Authentication Protocol
A protocol that challenges a system to verify identity. CHAP is an improvement over Password Authentication Protocol (PAP) in which one-way hashing is incorporated into a three-way handshake. RFC 1334 applies to both PAP and CHAP.
An authentication protocol that operates over PPP and also encrypts usernames and passwords for transmission.
A remote-access authentication protocol used by PPP. [Sounds more like CHAP uses PPP??]
[Related to EAP, WiFi authentication]
[See also PAP and MS-CHAP]
CRAM-MD5
Challenge-Response Authentication Mechanism-Message Digest 5
An authentication mechanism built on the MD5 algorithm that provides some additional security when communicating over an unencrypted connection.
A challenge-response authentication mechanism.
N+ material is pretty vague on this, if even mentions at all. From website:
CRAM-MD5 is a widely used challenge-response mechanism that transfers hashed passwords instead of clear text passwords. It is official deprecated, initially in favor of first DIGEST-MD5 but today SCRAM-SHA-1. For insecure channels (e.g., when TLS is not used), it is has better properties than PLAIN since the unhashed password is not leaked. The disadvantage with hashed passwords is that the server cannot use normal authentication infrastructures such as PAM, because the server must have access to the unhashed password in order to validate every authentication attempt.
CVE
Common Vulnerabilities and Exposure
Website that catalogs / indexes cybersecurity vulnerabilities. May be incorporated into security tools, etc.
https://cve.mitre.org/
[This was in Messer’s section on zero-day attacks, but I ignored it, thinking it wouldn’t be on test]
CVW
Collaborative Virtual Workspace
A software tool designed to support teams working across geographical distances.
–
An environment used for collaboration and interaction of participants that may be spread over large distances.
[May be set up as metaphorical “room” or “building” or “world.” You can access resources, chat room, etc. Was used by US military. MOOCs maybe?]
CWDM
Coarse Wave Division Multiplexing
One of the three types of multiplexing technologies used with fiber-optic cable (the other two being WDM and CWDM.)
[Note: Original WDM carries multiple light signals simultaneously by dividing a light beam into different wavelengths, or colors, on a single fiber. Like a prism. Originally only provided two wavelengths / channels per strand of fiber]
CWDM lowers cost by spacing frequency bands wider apart to allow for cheaper transceiver equipment. Coarse WDM multiplexers typically can support 4, 8, 16, or 18 channels per fiber. The effective distance of CWDM is more limited than DWDM because signal is not amplified.
An alternative to DWDM that is commonly used with television cable networks. The main thing to know about it is that it has relaxed stabilization requirements; thus, you can have vastly different speeds for download than upload.
[See also DWDM]
[Good write-up of these in Jill West book]
DaaS
Desktop as a Service
A service model in which desktop services, such as VDI, are provided virtually from a third-party provider, eliminating the need to build and manage your own infrastructure. [So basically, it’s operating system as a service?]
e.g. Citrix, Microsoft, Amazon, VMWare
VDI - Virtual desktop infrastructure (VDI) is a desktop virtualization technology wherein a desktop operating system, typically Microsoft Windows, runs and is managed in a data center. The virtual desktop image is delivered over a network to an endpoint device, which allows the user to interact with the operating system and its applications as if they were running locally. The endpoint may be a traditional PC, thin client device or a mobile device.
[Apparently also used for Data as a Service]
[See also CaaS, MaaS, and SECaaS]
DCS
Distributed Computer System or Distributed Control System
A computerized control system for a process or plant usually with many control loops, in which autonomous controllers are distributed throughout the system, but there is no central operator supervisory control. This is in contrast to systems that use centralized controllers; either discrete controllers located at a central control room or within a central computer. The DCS concept increases reliability and reduces installation costs by localizing control functions near the process plant, with remote monitoring and supervision.
Distributed control systems first emerged in large, high value, safety critical process industries, and were attractive because the DCS manufacturer would supply both the local control level and central supervisory equipment as an integrated package, thus reducing design integration risk. Today the functionality of SCADA and DCS systems are very similar, but DCS tends to be used on large continuous process plants where high reliability and security is important, and the control room is not geographically remote.
[See ICS and SCADA]
DLR
Device Level Ring
A protocol that provides a means of detecting, managing, and recovering from faults in a ring-based topology network. If a failure occurs in the ring, the communication essentially turns around and starts traveling around the ring in the opposite direction, reaching their destination like nothing ever happened.
In short, it allows a system to tolerate a disconnect or failure without any consequences to performance and recover before the system even notices.
(‘Ring topology’ here does not refer to a backbone network ring of switches, but rather a ring that you would find inside of a cabinet with daisy-chained devices leveraging the dual Ethernet ports found on some pieces of hardware.)
DPI
Deep Packet Inspection
A type of data processing that inspects in detail the data being sent over a computer network, and may take actions such as alerting, blocking, re-routing, or logging it accordingly. Deep packet inspection is often used to baseline application behavior, analyze network usage, troubleshoot network performance, ensure that data is in the correct format, check for malicious code, eavesdropping, and internet censorship.
WireShark offers DPI. So do NGFW. Wiki says could be at Layer 2 and 3. Or could be Layers 2 to 7. One of my books emphasizes Layer 7.
DR
Designated Router
An OSPF router intended to reduce network traffic by maintaining the complete routing database and then sending updates to the other routers on the shared network segment.
OR: In the context of OSPF, a router normally selected automatically to serve as a central collection point for routing information on a network.
[Is this really not in Messer notes?]
DSSS v. FHSS
Direct Sequence Spread Spectrum v.
Frequency Hopping Spread Spectrum
[For short definitions, see bottom]
Two variations in the initial 802.11 wireless standard. These original standards are far too slow for modern networking needs and are no longer deployed.
Spread spectrum refers to the manner in which data signals travel through a radio frequency. With spread spectrum, data does not travel straight through a single RF band; this type of transmission is known as narrowband transmission. Spread spectrum, however, requires that data signals either alternate between carrier frequencies or constantly change their data pattern. Although the shortest distance between two points is a straight line (narrowband), spread spectrum is designed to trade bandwidth efficiency for reliability, integrity, and security. Spread-spectrum signal strategies use more bandwidth than in the case of narrowband transmission, but the trade-off is a data signal that is clearer and easier to detect.
Frequency-hopping spread-spectrum (FHSS) requires the use of narrowband signals that change frequencies in a predictable pattern. The term frequency hopping refers to data signals hopping between narrow channels. For example, consider the 2.4 GHz frequency band used by 802.11b/g. This range is divided into 70 narrow channels of 1 MHz each. Somewhere between 20 and several hundred milliseconds, the signal hops to a new channel following a predetermined cyclical pattern.
Because data signals using FHSS switch between RF bands, they have a strong resistance to interference and environmental factors. The FHSS signal strategy makes it well suited for installations designed to cover a large geographic area and where using directional antennas to minimize the influence of environmental factors is not possible.
FHSS is not the preferred spread-spectrum technology for today’s wireless standards. However, FHSS is used for some lesser-used standards and for cellular deployments for fixed broadband wireless access (BWA), where the use of DSSS (discussed next) is virtually impossible because of its limitations.
With DSSS transmissions, the signal is spread over a full transmission frequency spectrum. For every bit of data sent, a redundant bit pattern is also sent. This 32-bit pattern is called a chip. These redundant bits of data provide both security and delivery assurance. The reason transmissions are so safe and reliable is because the system sends so many redundant copies of the data, and only a single copy is required to have complete transmission of the data or information. DSSS can minimize the effects of interference and background noise.
As for a comparison between the two, DSSS has the advantage of providing better security and signal delivery than FHSS, but it is a sensitive technology, affected by many environmental factors.
SUMMARIES:
DSSS:
A modulation technique that, like other spread-spectrum technologies, distributes lower-level signals over several frequencies simultaneously.
Or:
A modulation technique in which the transmitted signal takes up more than the information signal that modulates the carrier or broadcast frequency. [Huh?]
-
FHSS:
A wireless signaling technique in which a signal jumps
between several different frequencies within a band
in a synchronization pattern known to the channel’s
receiver and transmitter.
OR
A multiple access method of transferring radio signals in the frequency-hopping code division multiple access (FH-CDMA) scheme. [Huh?
DWDM
Dense Wavelength Division Multiplexing
One of the three types of multiplexing technologies used with fiber-optic cable (the other two being WDM and CWDM.)
[Note: Original WDM carries multiple light signals simultaneously by dividing a light beam into different wavelengths, or colors, on a single fiber. Like a prism. Originally only provided two wavelengths / channels per strand of fiber]
Increases the number of channels provided by normal WDM to between 80 and 320 channels. Dense WDM can be amplified en route and is typically used on high-bandwidth or long-distance WAN links, such as the connection between a large ISP and its (even larger) NSP (network service provider). [HOW??]
A form of multiplexing optical signals that replaces SONET/SDH regenerators with erbium doped fiber amplifiers (EDFAs) and can also amplify the signal and enable it to travel a greater distance. The main components of a DWDM system include the following:
Terminal multiplexer
Line repeaters
Terminal demultiplexer
[Huh??]
[Book says make you understand that DWDM works with SONET/SDH. So doesn’t replace them. Replaces something they used previously?]
[See also CWDM]
[Messer does mention this in passing. He said it’s a topology that may run under ethernet inside a provider’s network (Metropolitan-area Network). Not sure it made it into flashcards.
EBCDIC
Extended Binary Coded Decimal Interchange Code
A data format used by IBM mainframes? Makes no sense why this is included on text. Not mentioned in most of the books. Only place I see it mentioned is in references of it being converted to and from ASCII as an example of something that occurs that OSI Layer 6 (Presentation Layer.)
EDNS
Extension Mechanism for DNS
As specified by the Internet Engineering Task Force as RFC 2671, EDNS increases the size of the flags fields, return codes, and label types available in basic DNS
[Okay. But what’s the context / point??]
A mechanism that expands DNS parameters, thereby
increasing the protocol’s functionality.
From Meyers:
If you think about what DNS does, you can appreciate that it can be a big security issue. Simply querying a DNS server gives you a list of every computer name and IP address that it serves. This isn’t the kind of
information we want bad guys to have. The big fix is called DNS Security Extensions (DNSSEC). DNSSEC is an authorization and integrity protocol designed to prevent bad guys from impersonating legitimate DNS servers. It’s implemented through extension mechanisms for DNS (EDNS), a specification that expanded several parameter sizes but maintained backward compatibility with earlier DNS servers.
[Funny, because I was actually reading that EDNS opened door for amplified attacks?]
