Network + 5.2 Common Cabling and Physical Interface Issues

Cable Issues

different types of cables and their appropriate use is crucial for ensuring optimal network functionality.

Incorrect Cable Use

Using the wrong cable type causes failures, poor performance, and errors.

Single-mode fiber

Long distance, small core, high bandwidth, low attenuation.

Multimode fiber

Short distance, larger core, more dispersion.

Fiber mismatch

Causes signal loss, attenuation, and reduced bandwidth.

Category 5/6/7/8 Cable Issues

Limited data transfer speeds and leads to increased errors

Cat mismatch impact

Causes latency, slowdowns, and unsupported high-speed apps.

UTP in high EMI environments

Leads to signal degradation and corruption.

Shielding mismatch impact

Causes retransmissions and poor reliability.

Signal degradation

Loss of signal quality due to distance, interference, or damage.

Effects of degradation

Slow speeds, errors, and intermittent connectivity.

Crosstalk

Signal interference between adjacent cables.

Near-End Crosstalk (NEXT)

Interference measured at the transmitting end.

Far-End Crosstalk (FEXT)

Interference measured at the receiving end.

Crosstalk impact

Corrupted data and reduced throughput.

Interference

disruption of signal transmission caused by electromagnetic signals from other electronic devices or cables

Attenuation

Gradual loss of signal strength as it travels through a cable or medium

Improper Termination

When network cables aren’t correctly terminated with the appropriate connectors or techniques

Transmitter (TX)/Receiver (RX) Transposed

Happens when a transmitter and receiver wires are incorrectly connected, causing communication failuresI

Interface Issues

Impact network performance, leading to reduced efficiency and increased troubleshooting effortsIn

Increasing Interface Counters

Tracks various metrics related to network traffic and errors.

Cyclic Redundancy Check (CRC) Errors

When a mismatch in the data checksum, indicating data corruption during transmission

Runts

Packets that’s smaller than the minimum allowed size (less than 64 bytes)

Giants

Packets axceed the maximum allowed size (usually greater than 1518 bytes for Ethernet frames)

Drops

Packets are discarded due to congestion, buffer overflow, or configuration issues

Port Status Issues

affect network connectivity and performance, requiring attention to maintain proper network operation.

Error-disabled

Port shut down automatically due to errors or security violations.

Administratively down

Port manually disabled by an administrator.

Suspended

Port temporarily disabled due to policy or protocol violations.

Hardware Issues

Significantly impact network performance and reliability, necessitating timely identification and resolution

Power over Ethernet (PoE) Issues

Allos network cables to carry electrical power, simplifying the installation of networked devices like IP cameras and wireless access points

Power Budget Exceeded

Devices fail to power on or behave intermittently.

Incorrect Standard

Causes insufficient or no power delivery.

Mismatched transceivers

Cause no link, errors, or unstable connections.

Poor signal strength

Leads to high errors, packet loss, or no connectivity.