Infrastructure and components

Cable

• The cable and components used in structured cabling systems is defined in the standards

– EIA/TIA 568 x • There are a number of different levels of cables and components known

as Catagories

– ISO 11801 • There are a number of different levels of cables and components known

as Classes

Categories

Specified in TIA/EIA 568 X (i.e. In various 568 standards)Cat 1: Previously used for POTS telephone communications, ISDN and doorbell

wiring.

Cat 2: Previously was frequently used on 4 Mbit/s token ring networks.

Cat 3: used for data networks using frequencies up to 16 MHz. Historically popular for 10 Mbit/s Ethernet networks.

Cat 4: Provided performance of up to 20 MHz, and was frequently used on 16 Mbit/s token ring networks.

Cat 5: Provided performance of up to 100 MHz, and was frequently used on 100 Mbit/s Ethernet networks. May be unsuitable for 1000BASE-T gigabit

ethernet.

Cat 5e: Provides performance of up to 100 MHz, and is frequently used for both 100 Mbit/s and Gigabit Ethernet networks.

Cat 6: Provides performance of up to 250 MHz, more than double category 5 and 5e.

Cat 6a: Provides performance of up to 500 MHz, double that of category 6. Suitable for 10GBase-T.

Categories

• Cat 1: Currently unrecognized by TIA/EIA.

• Cat 2: Currently unrecognized by TIA/EIA.

• Cat 3: Currently defined in TIA/EIA-568-B.

• Cat 4: Currently unrecognized by TIA/EIA.

• Cat 5: Currently unrecognized by TIA/EIA.

• Cat 5e: Currently defined in TIA/EIA-568-B.

• Cat 6: Currently defined in TIA/EIA-568-B.

• Cat 6a: Currently defined in ANSI/TIA/EIA-568-B.2-10.

Category & data networks history

• CAT3 – 10Mbit/s networks

• CAT4 – Developed for increased bit rates but was superseded by CAT5

• CAT5 – 100MHz bandwidth easily carried 100Mbits/s

• CAT5e – Was developed because a badly installed CAT5 system could not

carry Gigabit Ethernet

• CAT6 – Easily carries Gigabit ethernet, future proofs network

• CAT6a – Designed to carry 10 Gigabit Ethernet

Classes

• Specified in ISO 11801– Class A: up to 100 kHz (category 1)– Class B: up to 1 MHz (category 2)– Class C: up to 16 MHz (category 3)– Class D: up to 100 MHz (category 5e)– Class E: up to 250 MHz (category 6)– Class F: up to 600 MHz (category 7)

Twisted pair

• Two conductors are wound together to cancel out EMI– From external sources (entering cable)– From crosstalk (leaving cable)

• The two wires typically carry equal and opposite signals (differential mode)

• Noise on the pairs is mostly cancelled out– Each wire have similar amounts of EMI– EMI is 180 degrees out of phase with each other

• Usually each pair has a different twist ratio

• Primary Colours– White– Red– Black– Yellow– Violet

• Secondary Colours– Blue– Orange– Green– Brown– Slate (grey)

25 pair cable

Telecommunications outlet

• Also known as a TO

• Standard specifies RJ45 connector

• Must be wired T568A or T568B

IDC

• Insulation displacement connector

• Connector that pierces the insulation on a wire to make the connection

• Removes the need to strip the wire before connecting

• Must be wired T568A or T568B

• Cold Welds materials together ????

Comparing an IDC connection (LH) with a crimped connection (RH)

www.ami.ac.uk

Telecommunications outlet 2

• At least one should be– 4 Pair 100 OHM UTP

• The other can be:– 4 Pair 100 OHM UTP OR– 2 Pair 150 OHM STP OR– 2 Strand, 62.5/125

multimode optical fibre

T568A and T568B pinouts

1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8

T568A T568B

1 2 3 4 5 6 7 8

1

2

3 4V VV

V

1 2 3 4 5 6 7 8

1

3

2 4V VV

V

• TIA-568-A and TIA-568-B are referring to the ANSI/EIA/TIA-

568-A and ANSI/EIA/TIA-568-B wiring standards

• T568A is a jack wiring pattern, one of the two in the

standards; the other is T568B

• T568A

– Used in America

• T568B

– Used in Europe

To clear any confusion

Cable types

• The standard recognises the following cable types– 4-pair 100 Ω unshielded twisted-pair (UTP) or screened

twisted-pair (F/UTP)– 4-pair 100 Ω fully shielded twisted-pair (S/FTP) (ISO/IEC

11801:2002 only)– 2-fiber (duplex) 62.5/125µm or 50/125µm

• 62.5/125µm USA standards• 50/125µm & 62.5/125µm European standards• Duplex SC connectors

– Multi-unit cables are allowed, • Must satisfy the hybrid/bundled cable requirements of TIA/EIA-568-B.2,

ISO/IEC 11801:2002 • Under carpet cabling is no longer recognized by that standard ISO/IEC

11801:2002

Work area

• Work area equipment and cables covered by 568-B.1 and 11801:2002

• Work area cables to be a maximum of 3m

• Exception to the 3m length discussed later

• 2 telecommunications outlets per work area minimum

• Patch leads are the same Category as the cabling

Work area II

• 1st outlet– Must be a 4 pair twisted

pair cable• Shielded

• Unshielded

– Category 6 is recommended

• 2nd outlet can be either– A 4 pair twisted pair

cable• Shielded

• Unshielded

– A pair of multimode optical fibres

A.Customer Premises Equipment B.Equipment Cord C.Patchcords/cross-connect jumpers, including equipment cables/cords, should not

exceed 5m (16 ft.).Note: ISO/IEC 11801:2002 specifies a max. patchcord/ cross-connect length of 5m (16.4 ft.), which does not include equipment cables/cords.

D.Horizontal cable 90m (295 ft.) max. total E.Transition point of consolidation point(optional) F. Telecommunications outlet/connector (TO) G.Work Area (WA) Equipment cord

Other Rules

• Bridged taps and splices are not allowed– Fiber splices are allowed for fiber optic cables

• Application specific components shall not be installed as part of the horizontal cabling

– eg. splitters, baluns

• Cabling shall be configured in a star topology

Patch leads and equipment cords

• Maximum combined length of 10m– Parts b,c & g

• Maximum copper link length 100m– 90m + cords (10m)