Ethernet Cable Types and Connectors

Ethernet Cable Types

• Cat 3 Ethernet cables support a maximum speed of 10 Mbps and a frequency of 16 MHz, often found in older telephone systems.
• Cat 5 Ethernet cables support 100 Mbps and a frequency of 100 MHz, offering faster speeds than Cat 3.
• Cat 5e Ethernet cables support 1 Gbps and a frequency of 100 MHz, enabling Gigabit Ethernet connectivity.
• Cat 6 Ethernet cables support 1 Gbps and a frequency exceeding 250 MHz, providing improved performance over Cat 5e.
• Cat 6a Ethernet cables support 10 Gbps and a frequency of 500 MHz, capable of higher speeds and improved signal integrity.
• Cat 7 Ethernet cables support 10 Gbps and a frequency of 600 MHz, offering even better performance than Cat 6a.
• Cat 8 Ethernet cables support 25/40 Gbps and a frequency of 2000 MHz, enabling even higher bandwidths and advanced applications.

Twisted Pair Cable Connectors

• RJ-45 connectors are the most common type for UTP cables, with 8 pins adhering to the TIA/EIA 568 standard.
• RJ-11 connectors are smaller versions of RJ-45 with 4 pins, primarily used for phone connections (regular and ADSL).
• Most RJ-45 plugs (female) can accommodate an RJ-11 jack due to their size compatibility.

RJ-45 Patch Cables

• RJ-45 patch cables feature an RJ-45 jack (male connector) at both ends.
• The T568 Specification outlines two pinout patterns: T568A and T568B.
• Straight Through Cables use the same pinout at both ends (either T568A or T568B), used for connecting unlike devices (PC to Switch, Router to Switch).
• Cross Over Cables utilize different pinouts at each end (one T568A, the other T568B), used for connecting like devices (Switch to Switch, PC to PC, Router to Router, PC to Router).

Fiber Optic Cables

• Fiber optic cables transmit data using light waves.
• They consist of a thin glass tube, similar in diameter to a human hair.
• Fiber optic cables offer high bitrates over long distances, up to 1 Tbps (1000 Gbps) over 100 Km (single mode).
• Light signals are unaffected by electrical noise, providing improved signal integrity.

Open Networking Standards Organizations

• IANA (Internet Assigned Numbers Authority): Responsible for assigning IP addresses to Regional Numbering Authorities.
• IEEE (Institute of Electrical and Electronic Engineers): Sets standards for physical equipment and MAC addresses.
• ANSI (American National Standards Institute): Develops and disseminates various standards and measures, including business norms and standards within the United States.
• ITU (International Telecommunication Union): Coordinates telecommunication operations and services worldwide.
• ISO (International Organization for Standardization): Develops and publishes international standards in all technical and nontechnical fields, excluding electrical and electronic engineering, including the OSI 7-Layer Reference Model.

Data Network Reference Models

• The OSI (Open System Interconnect) Model consists of 7 layers, breaking down network communications into smaller, manageable components, facilitating easier troubleshooting and technology evolution.
• The TCP/IP Model combines OSI functions into fewer layers, providing a simplified view of network communications with 4 layers.

Purposes of Layers in Network Models

• Reduces Problem Complexity: Breaks down complex problems into smaller, easier to solve ones.
• Isolates Problems: Allows engineers to focus on specific layers without needing knowledge of other layers, streamlining troubleshooting.
• Accelerates Technology Evolution: Changes in one layer do not necessitate modifications in other layers, promoting faster development.

Reference Models

• Protocol Data Unit (PDU): The unit of information at each layer of the OSI Model, gaining additional information and control fields as it passes through the layers (encapsulation).
• Jumbo Frames: Frames with data exceeding 1500 bytes are considered jumbo or baby giant frames, typically supported by modern switches and NICs.
• Dropped Frames: Frames smaller or larger than the allowed minimum or maximum size are considered invalid and are dropped.

Network Topologies

• Physical Topology: The arrangement of devices physically connected to each other.
• Logical Topology: How devices communicate within the network.
• Bus Topology: All nodes connect to a common media, resembling wireless network functionality.
• Ring Topology: Each node has two connections, one to each neighbor. Traffic circulates unidirectionally through all nodes.
• Star Topology: Each node connects to a central point, often a switch, commonly used for small networks.
• Mesh Topology:
  • Full Mesh: Each node is connected to every other node via a point-to-point connection.
  • Partial Mesh: Some nodes connect to all other nodes, while others connect to only specific nodes.

Forwarding Frames

• Hubs and Switches:
  • Switches operate at Layer 2 of the OSI Model. They learn MAC addresses and forward frames directly to the destination device.
  • Hubs operate at Layer 1. They act as a broadcast device, forwarding all data to every port, leading to collisions on the media. Hubs require half-duplex operation.
• Collision Domains: Collision domains are media segments where collisions can occur.

IPv4 Address Types

• Unicast Address: Used for single hosts, where the host portion cannot be all 1's or all 0's. (One-to-One).
• Network Address (Subnet Address): Represents the entire network, with the network portion set to all 1's and the host portion to all 0's.
• Directed Broadcast: The network portion is all 1's and the host portion is all 1's. All hosts on the network receive this packet (One-to-All).
• Multicast: Uses Class D addresses, where all devices in a multicast group receive the packet (One-to-Many).

IPv4 Address Types - Special Addresses

• Loopback Addresses: A reserved range from 127.0.0.0 to 127.255.255.255, used for testing and internal process communication on a single host. Usually represented as 127.0.0.1/8.
• APIPA (Automatic Private IP Addressing): A Microsoft protocol allowing devices to self-assign addresses within a local network when unable to contact a DHCP server, using the address space 169.254.0.0/16.

IPv6 Characteristics

• Connectionless: No awareness of the destination, meaning delivery is not guaranteed.
• Best Effort: Delivery is unreliable, with no guarantees of success.
• Media Independent: Can be carried by any Layer 2 protocol, with the L2 protocol informing IP of the MTU.
• No Acknowledgement: No confirmation of packet receipt at the IP layer.
• Layer 4 Reliability: TCP provides reliability, not IP.
• Fragmentation: IPv4 can fragment packets to adapt to different Layer 2 MTU sizes.
• Routable Addresses: IPv6 does not require NAT, all addresses are routable on public networks.

IPv6 Packet Header

• Version: Indicates IPv6 with 6 decimal (0110 binary).
• Traffic Class: Defines priorities for Quality of Service (QoS).
• Hop Limit: Indicates the number of hops a packet can travel before being discarded.

APIs (Application Programming Interfaces)

• Application: Refers to software with a distinct function.
• Interface: Represents a contract between two applications, defining how they communicate using requests and responses.
• API Documentation: Documents the structure of requests and responses for developers.

Web APIs

• Web API: Provides an interface between a web server and web browser, handling data exchange.
• REST APIs: A type of Web API that uses the REST architectural style, employing standard methods like GET, POST, PUT, and DELETE.
• SOAP APIs: These APIs utilize the Simple Object Access Protocol, exchanging XML messages between client and server.
• RPC APIs: These APIs utilize Remote Procedure Calls, enabling the client to execute functions on the server.
• WebSocket APIs: Modern web APIs employing JSON objects for data exchange, supporting two-way communication between client and server.

API Integrations

• API integrations connect client and server applications for automatic data updates.
• Examples include automatic syncing of images from your phone to the cloud, and automatic time and date updates on your laptop when you travel.