Network cabling

1.1 Install Physical Hardware

📘CompTIA Server+ (SK0-005) 

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1. Redundant Networking

Redundant networking is all about reliability. In IT environments like data centers, downtime is not acceptable. Redundant networking ensures that if one network path fails, another path can handle the traffic.

Key points to remember:

• Redundant links: Multiple cables connecting switches, servers, or routers.
• Redundant devices: Two or more network switches or routers providing backup.
• Failover: Automatic switching to a backup network connection when the main one fails.
• High availability: Redundancy improves uptime for critical servers and services.

Exam Tip: You may see questions asking why redundancy is important—answer: it prevents network downtime and ensures continuous connectivity.

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2. Twisted Pair Cabling

Twisted pair cables are the most common type of networking cables in IT environments. They consist of pairs of wires twisted together to reduce interference.

Types:

1. Unshielded Twisted Pair (UTP)
   • Most common type.
   • Categories include Cat5e, Cat6, Cat6a, Cat7.
   • Supports different speeds:
     • Cat5e → 1 Gbps (Gigabit Ethernet)
     • Cat6 → 10 Gbps up to 55 meters
     • Cat6a → 10 Gbps up to 100 meters
     • Cat7 → 10 Gbps+, better shielding
2. Shielded Twisted Pair (STP)
   • Has extra shielding to reduce electromagnetic interference.
   • Used in environments with lots of electronic devices that cause interference.

Connector:

• RJ-45 is the standard connector for twisted pair cables.

Exam Tip: Remember the categories (Cat5e, Cat6, etc.) and their speed limits.

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3. Fiber Optic Cabling

Fiber optic cables use light to transmit data, which allows for higher speeds and longer distances than copper cables.

Types of Fiber:

1. Single-mode fiber (SMF)
   • Uses a single light path.
   • Very long distance (up to tens of kilometers).
   • High speed, used for connecting data centers or large networks.
2. Multimode fiber (MMF)
   • Uses multiple light paths.
   • Shorter distances (hundreds of meters).
   • Usually cheaper than single-mode.

Connector Types:

• SC (Subscriber Connector) – Square-shaped, used in data centers.
• LC (Lucent Connector) – Small form factor, widely used in modern switches and servers.
• ST (Straight Tip) – Older style, less common now.

Exam Tip: Know single-mode vs. multimode and SC vs. LC connectors.

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4. Network Speeds

Network speeds determine how fast data moves across the network. In modern IT environments, the following speeds are common:

1. Gigabit Ethernet (1 Gbps)
   • Standard for server connections and office networks.
   • Can run over Cat5e or higher twisted pair cables or fiber.
2. 10 Gigabit Ethernet (10 GbE)
   • Used in data centers and high-speed server connections.
   • Requires Cat6a/Cat7 twisted pair or fiber cabling.
3. 25/40/100 GbE
   • High-speed connections for enterprise data centers.

Exam Tip: You may be asked which cable types support certain speeds:

• Cat5e → 1 Gbps
• Cat6a/Cat7 → 10 Gbps
• Fiber → 10 Gbps+

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5. SFP, SFP+, QSFP+

These are modular transceivers that allow network devices to support different types of cables and speeds.

1. SFP (Small Form-factor Pluggable)
   • Supports speeds up to 1 Gbps.
   • Can be used with copper or fiber.
2. SFP+
   • Enhanced version, supports 10 Gbps.
   • Often used for server uplinks to switches.
3. QSFP+ (Quad SFP+)
   • Supports 40 Gbps.
   • Combines 4 channels of 10 Gbps each.

Exam Tip: Remember the naming:

• SFP = 1 Gbps
• SFP+ = 10 Gbps
• QSFP+ = 40 Gbps

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6. Key Exam Takeaways

• Redundant networking prevents downtime and ensures continuous connectivity.
• Twisted pair cables (UTP/STP) use RJ-45 connectors; categories affect speed and distance.
• Fiber optic cables (single-mode/multimode) use SC or LC connectors and support long distances.
• Gigabit and 10 Gigabit Ethernet are common speeds; cable type matters.
• SFP, SFP+, QSFP+ transceivers allow network devices to adapt to different cable types and speeds.

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✅ Simplified summary for memory:

• Redundancy = backup paths
• Twisted pair = copper, RJ-45, Cat5e/6/6a/7
• Fiber = light, SC/LC, single vs. multimode
• Speed = 1 Gbps (Gigabit), 10 Gbps (10 GigE)
• Modules = SFP (1G), SFP+ (10G), QSFP+ (40G)