Net. Topologies and Cabling

Network Standard Topologies

Mesh Topology

Description: Every system is connected to every other system, providing multiple paths for data transmission.

• Types:

  • Full Mesh: Every node connects to every other node. Common in critical networks like bank networks.
  • Partial Mesh: Some nodes are connected to all others, but some only to a few. Useful when full mesh is too costly or complex.

• Advantages:

  • High Redundancy: Ensures data transmission even if some connections fail.
  • Fault Tolerance: Can handle multiple failures without affecting connectivity.

• Example Hardware/Software:

  • BitTorrent. When you download files via BitTorrent, your computer connects to multiple other computers that have the same file. There's no central server. Each computer (or peer) shares a piece of the file with each other.
  • Cryptocurrencies like Bitcoin and Ethereum utilize blockchain technology

Mesh topology is prevalent in WANs, such as the Internet backbone, where constant connectivity is crucial.

Ring Topology

Description: Systems are connected in a circular fashion. Data often travels in one direction.

• Traffic Management: A 'token' system is utilized to prevent collisions and manage traffic.

• Example Hardware/Software:

  • IBM's Token Ring network in the past used MAUs (Multistation Access Units) as a hardware device to create and maintain the ring topology.
  • FDDI (Fiber Distributed Data Interface): Another ring-based technology, but focused on fiber optics.

Ring topologies have become less common due to technological advances and maintenance challenges.

Bus Topology

Description: All devices share a single communication line or 'bus'.

• Functionality: Possible data collisions if multiple devices transmit simultaneously.

• Example Hardware/Software:

  • 10Base2 (Thin Ethernet) and 10Base5 (Thick Ethernet): Ethernet standards that used coaxial cables in bus topology.
  • BNC connectors and T-connectors were standard for attaching devices to the bus in 10Base2 networks.

Collisions such as in early Ethernet setups, can hinder network performance. Today, this design is largely obsolete.

Star Topology

Description: All devices connect to a central hub or switch.

• Advantages:

  • Ease of Installation & Maintenance: Simplified troubleshooting and scalability.
  • Isolation of Devices: Individual device failures don't cripple the whole network.

Example Hardware/Software:

• Ethernet switches (e.g., Cisco Catalyst switches, Netgear ProSafe switches): Modern devices that intelligently forward data only to the intended recipient.
• Call of Duty's P2P System: Operates like a star topology where one player's system is the central host. All players connect to this host. If the host disconnects, the game briefly pauses for "host migration" to a new player.

Star topology, especially with switches like Cisco's, is predominant in modern LANs due to its robustness and simplicity.

Cabling Types & Throughput

UTP Categories - Copper Cable

UTP, which stands for Unshielded Twisted Pair, refers to a type of cable construction rather than a specific kind of data communication.

Cat	Data Rate	Max Length	Time	Application
Cat 3	10 Mbps	100 meters	Early 1990s	10BASE-T Ethernet (Original Ethernet) and voice services, Token Ring
Cat 5	100 Mbps	100 meters	Mid 1990s	100BASE-TX Ethernet (FastEthernet), Token Ring
Cat 5e	1 Gbps	100 meters	Late 1990s	1000BASE-T (Gigabit Ethernet) and 100BASE-TX
Cat 6	1 Gbps (10 Gbps up to 55m)	100 meters	Early 2000s	1000BASE-T (Gigabit Ethernet) and 10GBASE-T (short distances),
Cat 6a	10 Gbps	100 meters	Late 2000s	10GBASE-T (10 Gigabit Ethernet)
Cat 7	10 Gbps	100 meters	2010s	10GBASE-T for more industrial applications
Cat 7a	40 Gbps (up to 50m) / 100 Gbps (up to 15m)	100 meters	Mid-2010s	High-speed data centers and 10GBASE-T
Cat 8	25-40 Gbps	30 meters	Late 2010s	Data centers for 25GBASE-T and 40GBASE-T

While UTP is commonly associated with Ethernet networking because of its widespread use in this application, the construction itself is not exclusive to Ethernet.

Ethernet Standards

Ethernet Standard	Max Speed	Max Distance	Installation Difficulty	Susceptibility to EMI
10BASE2	10 Mbps	185 meters	Moderate	Medium
10BASE5	10 Mbps	500 meters	Hard	Low
10BASE-T (UTP)	10 Mbps	100 meters	Easy	High
STP	155 Mbps	100 meters	Moderate	Low
100BASE-T/100BASE-TX	100 Mbps	100 meters	Easy	Moderate
1000BASE-T	1 Gbps	100 meters	Easy	Moderate to Low
Fiber-optic	2+ Gbps	2000+ meters	Hard	Very Low

Notes on Installation Difficulty and Susceptibility to EMI:

• 10BASE2 (Thinnet): Requires BNC connectors and terminators, making it more cumbersome than UTP installations.

• 10BASE5 (Thicknet): Its nickname "Thicknet" suggests its bulkiness. Requires AUI connectors, making installation more difficult than Thinnet or UTP.

• UTP (like for 10BASE-T): Generally easier to install, but more susceptible to EMI compared to shielded or coaxial cables.

• STP: Provides some shielding against EMI. It can be slightly more challenging to install than UTP due to the shielding and the need to ground.

• Fiber-optic: Installation is difficult due to the precision required when handling and connecting fibers. However, they offer the best protection against EMI since light signals are immune to electromagnetic interference.

---

Fiber Channel

Definition: A high-speed network technology primarily used for storage networking.

Key Features:

• Data Storage Solutions: Typically found in SAN (Storage Area Network) or NAS (Network-Attached Storage) solutions. Fibre Channel is often associated with SANs due to its high-speed capabilities.

• Transmission Mechanism: Uses fibre channeling to connect storage devices to a switch or network.

---

FCoE (Fiber Channel over Ethernet)

Definition: A mapping of Fibre Channel frames over Ethernet networks.

Key Features:

• Encapsulation: Allows Fibre Channel communications to be encapsulated and sent over Ethernet networks.

  Success: FCoE combines the robustness of Fibre Channel with the widespread infrastructure of Ethernet.

• Usage: Typically seen in data center settings to simplify and consolidate networking and storage communication.

---

iSCSI (Internet Small Computer System Interface)

Definition: An IP-based storage networking standard that links data storage facilities.

Key Features:

• IP-based: Allows for data transfers over local area networks (LANs), wide area networks (WANs), or the internet.

  Information: iSCSI offers an alternative to Fibre Channel, leveraging existing IP infrastructure.