Principles of Voice & Data

Lesson 3:Infrastructure Issues

and Standards

Bellevue Community CollegeBob Young, Instructor

Tip and Ring

Uptime (Reliability)

• Typical standard is 99.999%

• Slang term: "Five nines reliability"

• Downtime = 5 min., 15 sec. / year

MTBF

• Mean Time Between Failure

• "Predicted" amount of time a device will function before it needs to be repaired or replaced

• Downtime may occur for scheduled maintenance

ROI• Profit generated minus expense

incurred

• True ROI analysis requires capturing all costs:

– maintenance

– fuel, power

– training

– etc.

Environmental Issues

• Temperature extremes (hot or cold)

• Vibration and shock

• Humidity (too dry or too damp)

• Fire

• Altitude (air pressure affects cooling)

• Noise (humans beings are present)

EMC

• Electromagnetic Compatibility–"It works fine - if you put it in a

room all by itself!"

ESD

Electrostatic Discharge

Static Electricity

Transient

Transients

EMI

• Electromagnetic Interference–Also creates transients–Compounded by having lots

of equipment in the same room

–Motors, pumps, fans/blowers

RFI

Radio Frequency Interference

A device may emit RF energy intentionally or unintentionally

EMI/RFI Suppression

• Capacitors

• Inductors

• Line filters–Line filters are composed of

inductors, capacitors, or both

Shielding

• Shielding protects against EMI/RFI

• Shielding is not part of the ground system, even if the shield is grounded– Often, shielding won't handle the amount of

current that the ground must be able to handle.

Humidity

• Mold

• Corrosion

• Reduced insulation

• If it's too dry, the chance of Electrostatic Discharge (ESD) increases

Personnel Safety #1

• Equipment rooms are often cramped

• Tools

• Loose clothing

• Metal

• Safety glasses (what other clothing?)

• Working "solo"?

Personnel Safety #2• Be observant: wet floors, corrosion, gas

• Dust reduces electrical resistance, can be a fire hazard, is a respiratory concern, and can transport chemicals and bacteria

• Pest control: rattlesnakes, wasps, black widow spiders...

Personnel Safety #3

• Where do you turn off the equipment?

• Where is the main power cutoff?

• Where is the fire alarm?

• Where is firefighting equipment?

• Where is the first aid kit?

• Acid shower?

• Water main shutoff valve?

Moving On...

It's time to talk about

Standards Organizations

and

Regulatory Bodies

NEBS

Network Equipment Building System

3 Levels: Level 3 = Carrier Class

Originally Bellcore

Now Telcordia

NEBS Standards Documents

• GR-63-CORE - Physical Environment

• GR-1089-CORE - Electrical, EMI

• GR-253 - SONET

• GR-1221-CORE - Fiber Optic Networks• GR-326-CORE - Fiber Network Connections

• GR-487 - Outdoor Equipment

BABT

• Formerly "British Approvals Board for Telecommunications"

• Formerly a government entity (UK)

• Now a private corporation

• Serves the European Union (EU)

BABT

• BABT issues standards for telephony equipment

• Standardized metering for billing phone calls

• Evaluates business processes and quality control

BABT CNC"The product’s network connection has

been assessed to meet relevant and recognized standards and the continuing compliance of the product is regularly assessed."

BABT PQ

"This demonstrates that your quality system controlling production has been independently assessed by a radio and telecom terminal expert certification body."

BABT Blue Circle

BABT "Tick Mark"

Oftel

• Regulates telecom in the UK

• Licensing phone companies

• Regulates phone numbers– Specified Numbering Scheme (SNS)

• Regulates prices

• Handles complaints

• Not involved with physical equipment

ISO

• International Organization for Standardization

• From Greek, isos, meaning "equal"

• Develops standards for connecting networks together

ITL

Independent Testing Laboratory

ETSI

• European Telecommunications Standards Institutes

• EN Standards– EN 300 386: Electrical, EMI, RFI– EN 300 132: Standards for Power Supplies– EN 300 019: Environmental Concerns (for

the equipment)

ETSI World Headquarters

FCC #1

• Federal Communications Commission

• Code of Federal Regulations, Title 47

• Telecommunications

• Radio Communications

FCC #2

• Class A device = okay for CO, won't cause interference

• Class B device = approved for non-commercial, residential use

TIA

Telecommunications Industry Association

A private consortium of businesses

EIA

Electronic Industries Alliance

• Private organization

• Not just telecom

BSI

British Standards Institute

A private consortium of businesses

Moving On...

It's time to talk about

Cables

and

Connectors

Cabling Procedures

UTP and STP

• Wire Gauges

• Twisted-pair Categories– Note: CAT 7 is not approved yet

IBM Cabling Standard

DCE and DTE

• DCE–Data Communications Equipment

• DTE–Data Terminal Equipment

RJ-45 Connector

EIA/TIA 568A & B

Crossover Cables

RS-232

Amphenol Connectors

• 25 pair

• 50 wires

• Male and female connectors look very similar.

PVC & Plenum Cabling

• Two options:– Pay for plenum cable– Pay for conduit

Securing the Equipment

• Bolt it down

• Ground it

BT Premise Wiring

BT Master Jack

BT431A Master Jack

BT431A Slave Jack

BT431A Modular Connectors