General and Misc Flashcards
Error Correcting Code
Error Correcting Code (ECC) RAM is System memory (RAM) with built-in error correction security. It is more expensive than normal memory and requires motherboard support. It is typically only used in servers. It can detect and correct single bit errors. It can detect more than single-bit errors but cannot correct them.
Advanced RISC Machines (ARM)
s a designer of CPU and chipset architectures widely used in mobiles devices. RISC stands for reduced instruction set computing. RISC uses a small number of simple instructions that can be performed as a single operation.
Simultaneous multithreading (SMT) / Hyperthreading
to do the most amount of work possible in a single clock cycle.
Symmetric Multiprocessing (SMT)
Approach in which two or more CPUs are used.
Troubleshooting steps
- Identify the problem.
- Establish a theory.
- Test the theory.
- Establish a plan of action and implement.
- Verify full system functionality.
- Document the findings, actions, and outcomes.
Preboot Execution Environment (PXE)
A network standard that allows a computer to boot up and load an operating system directly from a network server instead of relying on a local hard drive. Commonly used for installing operating systems on multiple computers or troubleshooting issues without physical boot media.
Secure boot
Prevents unauthorized processes from executing during the boot operation. Under secure boot, computer firmware is configured with cryptographic keys that can identify trusted code.
Trusted Platform Module (TPM)
is a specification for hardware-based storage of digital certificates, cryptographic keys, and hashed passwords.
Hardware Security Module (HSM)
A USB thumb drive to store cryptographic material and keys.
Power over Ethernet (PoE)
means of supplying electrical power from a switch port over ordinary data cabling to a powered device such as VoIP handset, camera, or wireless access point. PoE standards: 802.3af (13W)/802.3at (25W)/802.3bt (51W-73W)
Power Injector
For PoE, the switch must be PoE enabled and if not we can use power injector.
Wi-Fi Analyzer
is a device or software that helps measure signal strength across different channels.
Long-range Fixed Wireless
high-gain microwave antennas to establish a point-to-point wireless link over long distances. A wireless signal power has three components: transmit power(dBm), Antenna gain (dBi)
CAT Standards
- CAT 5 (100 Mbps/100BASE-TX)
- CAT 5e (1 Gbps/ 1000BASE-T/ Gigabit Ethernet)
- CAT 6 (1Gbps/ 1000BASE-T/ Gigabit Ethernet)
CAT 6 (10 Gbps/ 10GBASE-T/ 10G Ethernet) - CAT 6A (10Gbps/ 10GBASE-T/ 10G Ethernet)
How to create a loopback plug
Connect one wire to pin 1 and 3 and another wire to 2 and 6
Network Tap
It intercepts the signal passing through a cable and sends them to a packet or protocol analyzer.
Plenum Cable
Type of cable that is fire-retardant and meets other strict fire safety standards.
Fiber Optic Categories
- Single-mode fiber: small core, long wavelength infrared signal, and supports data rates up to 10 Gbps or better.
- Multi-mode fiber: larger core, shorter wavelength infrared light, less expensive, and does not support high signaling speeds or long distance.
Fiber Optic connectors
- Straight tip (ST): push & twist
- Subscriber Connector (SC): push/pull design
- Lucent Connector (LC): tabbed push/pull
Geostationary Orbital Satellite Internet Access
A satellite-based Internet is a system of microwave transmissions where orbital satellite relay signals between receivers on earth and other satellites. Satellite internet connectivity is enabled through a reception antenna connected to the PC or network through a DVB-S modem.
Low Earth Orbital Satellite Internet Access
LEO satellites support better bandwidth and are lower latency. The drawback is that the satellites move relative to the surface of the Earth. The dish construction uses a technology called “phased array” to connect to different satellites as they pass overhead.
Global System for Mobile Communication (GSM)
3G format which allows subscribers to use SIM cards on an unlocked handset.
TCP/IP Layers
- Application: DHCP, DNS, FTP, HTTP/HTTPS, SMB, SMTP, IMAP, POP3, SSH, RDP, Telnet, LDAP, SNMP, Syslog
- Transport: TCP, UDP
- Internet: IP
- Link/ Network Interface: Ethernet Wi-Fi
Transport Layer Protocols
- Transmission Control Protocol: connection oriented, ensures packet delivery, correct order and error checking. Used in web browsing, email, FTP, etc.
- User Datagram Protocol: Connectionless, no guarantee of delivery, no retransmissions, good for video streaming, VoIP, DNS, and online gaming.
