This document discusses various common networking hardware components and connectors. It describes connectors such as BNC, DB, RJ, fiber optic SC and ST connectors, and the SCSI interface. BNC is used for thinnet coaxial cabling. DB connectors connect data terminal equipment and come in various pin configurations. RJ connectors are used for twisted-pair cabling, with RJ-45 being common for Ethernet. SC and ST are fiber optic connectors, while SCSI is an interface for connecting peripherals.

1. Network Hardware Components
--Mahesh Enumula

2. Introduction to Connectors

3. Connector
• A device that terminates a segment of cabling
or provides a point of entry for networking
devices such as computers, hubs, and routers.
• Connectors can be distinguished according to
their physical appearance and mating
properties, such as jacks and plugs (male
connectors) or sockets and ports (female
connectors).

4. • They can also be distinguished by their
different pinning configurations, such as DB9
and DB15 connectors, which have 9 and 15
pins, respectively.
• In addition, connectors are distinguished by
the kind of electrical interfaces they support.

5. Examples of connectors
• Connectors for serial interfaces, such as RS-
232 and V.35
• Ethernet connectors, such as RJ-45 and BNC
connectors
• Fiber-optic cabling connectors, such as SC and
ST connectors

6. Common networking and
Telecommunications connectors

7. Common networking and
telecommunications connectors-2

8. BNC connector
• BNC connector is a series of connectors used
for connecting thinnet coaxial cabling to
various networking components. BNC
connectors use a twist-and-lock mechanism
that provides a secure connection between
network cabling and components.

9. • BNC cable connector: Soldered or crimped to
the ends of a thinnet cable
• BNC T-connector: Used to connect a network
interface card (NIC) to a thinnet cable
segment
• BNC barrel connector: Used to connect two
pieces of thinnet cable
• BNC terminator: Provides a 50-ohm
termination for the free end of a thinnet cable

10. DB connector
• DB Connector is any connector used for
connecting data terminal equipment (DTE). The
letters “DB” stand for “data bus” and are followed
by a number that indicates the number of lines or
pins in the connector.
• DB connectors were formerly called D-series
connectors. DB connectors can be used for either
serial or parallel connections between devices.
Common members of the DB family include the
following:

11. • DB-9, a 9-pin serial connector for connecting modems,
serial printers, mouse devices, and so on
• DB-15, a 15-pin connector for connecting such devices as
Macintosh monitors and network interface cards
(NICs) for 10Base5 drop cables
• DB-25, a 25-pin connector for connecting Macintosh Small
Computer System Interface (SCSI) devices, modems, serial
printers, parallel cables, switch boxes, and so on
• DB-37, a 37-pin connector for connecting such devices as
routers and Channel Service Units (CSUs)
• DB-60, a 60-pin connector for connecting such devices as
Cisco routers

13. V series
• V series is a series of communication standards
developed by the International Telecommunication
Union (ITU).
• V series protocols define methodologies for exchanging
data over the public telephone system by using
telecommunications devices such as modems and
multiplexers. Various V series protocols define
interfaces between data terminal equipment (DTE)
such as computers and data communications
equipment (DCE) such as modems, or signaling
methods for use over the public telephone system

15. RJ Connectors
RJ Connectors are a family of push-and-click
connectors for twisted-pair wiring in
telephone and network wiring. RJ stands for
Registered Jack. RJ types define both a jack or
receptacle (female) and a plug (male) type of
connector.

17. The most common types of RJ
connectors
• RJ-11 connector: A 4-wire or 6-wire telephone-type connector that connects
telephones to wall plates. RJ-11 supports up to six wires, but usually only four are
used with the two-pair twisted-pair cabling commonly found in telephone cabling.
• RJ-45 connector: An 8-wire telephone-type connector used with twisted-pair
cabling for connecting computers, wall plates, patch panels, and other networking
components. RJ-45 is the standard type of connector for both unshielded twisted-
pair (UTP) and shielded twisted-pair (STP) cabling in star-topology Ethernet
networks such as 10BaseT and 100BaseT4. RJ-45 is defined in International
Organization for Standardization (ISO) standard 8877.
• RJ-48 connector: An 8-wire telephone-type connector used with twisted-pair
cabling for connecting T1 and 56-KB digital data service (DDS) lines. RJ-48 uses the
same jack as RJ-45 but uses a different pinning, with one pair of wires to transmit
signals, one pair to receive signals, one pair for drain, and one unused pair
(reserved for future use). RJ-48 connectors come in three varieties: RJ-48C and RJ-
48X for connecting T1 lines, and RJ-48S for connecting 56-KB DDS lines

18. Fiber Optic Connectors
• SC/ST connectors are used for connecting
fiber-optic cabling to networking devices. SC
stands for subscriber connector and ST stands
for straight tip..

19. • SC stands for subscriber connector and is a standard-duplex
fiber-optic connector with a square molded plastic body and
push-pull locking features. SC connectors are typically used
in data communication, CATV, and telephony environments.
• ST stands for straight tip, a high-performance fiber-optic
connector with round ceramic ferrules and bayonet locking
features. ST connectors are more common than SC
connectors.
• You can generally use SC and ST connectors with either
single-mode or multimode fiber-optic cabling. Coupling
receptacles for these connectors come in either panel-
mount or free-handing designs. For narrow space
installations, you can get 90-degree boot versions instead of
straight versions. SC and ST connectors come in both
simplex and duplex form.

21. SCSI
• SCSI stands for Small Computer System
Interface, is a hardware bus specification for
connecting peripherals to a computer using a
parallel transmission interface.