Technical Overview

Network Transport and Transmission Technologies

&Networking Terminology

Presented By Michael Restagno

Network Transport and Technologies

• ISDN

• T-carrier

• Sonet

ISDN

• Integrated Services Digital Network • Two types of channels, B (for "Bearer")

and D (for "Delta"). • B Channels have a bandwidth of 64kb

each and D Channels have a bandwidth of 16kb

• B Channels are used for data or voice, and D Channels are primarily used for signaling and control.

• 2 “flavors” of ISDN

– ISDN-BRI• 2 “B” Channels and “1” D Channel• Maximum combined bandwidth of 128kb

– ISDN-PRI• 23 “B” Channels and 1 “D” Channel• Maximum combined bandwidth of 1.544 Mbits

Each “B” channel can be designated for either voice or data.

Channels can be “pooled” to provide greater bandwidth.

ISDN

ISDN

• NCFS Responsibilities

– Extend Circuit if necessary– Install and maintain hardware– Connect ISDN circuit to interface card

ISDN

• Customer Utilization– Data transmission– Connection to voice PBX– Backup for T1

T-carrier (Digital Signal)

• T1 or DS1 contains 24 channels and delivers a bandwidth of 1.544 Mbit/s equivalent to ISDN-PRI– Uses STP cable (RJ45 or RJ48)

• T3 or DS3 contains 672 channels and is the equivalent of 28 T1’s with a bandwidth of 44.736 Mbit/s– Uses a pair of coax cables (BNC connectors)

for transmit and receive.

T-carrier (Digital Signal)

• T-carrier is connected to a CSU/DSU which is connected to the router’s serial port.

• Some routers use a combination CSU/DSU-serial card.

• CSU/DSU-Channel Service Unit/Data Service Unit – Used to split off the voice channels from the data

channels, allowing the voice channels to be connected to a phone system or PBX. The data lines are then connected to a router serial interface and often are used to provide Internet connectivity.

Installation

T-carrier (Digital Signal)

• NCFS Responsibilities– Locate MPOE (minimum point of entry) or

DEMARC– Extend T1 circuit to equipment location (if

necessary)– Connect circuit to equipment– Provide hard loopback if requested for

troubleshooting

T-carrier (Digital Signal)

• Typical T1 hard loopback plug

                                                          

1 loops back on to 4 2 loops back on to 5

• Basic example of channeled T1 – Router setup.

SONET

• Synchronous Optical Network• SONET commonly transmits data at speeds

between 155 megabits per second (Mbps) and 2.5 gigabits per second (Gbps).

• An optical fiber point-to-point or ring network backbone

• Connected using Sonet multiplexers• Sometimes referred to as “The Ring”

SONET

• A SONET/SDH transmission network is composed of several pieces of equipment, including:

– Add-drop multiplexer (ADM) – Digital cross-connect system (DCS)

SONET

• Classifications and Speeds– North America

uses the terms STS (synchronous transport signal) or OC (optical carrier)

SONET STANDARD LINE SPEEDS

 

    DS1/T1 DS3

LEVEL RATE (Mbps)

EQUIVALENT EQUIVALENT

       

OC-1/STS-1

51.84 28 1

OC-3/STS-3

155.52 84 3

OC-12/STS-12

622.08 336 12

OC-48/STS-48

2,488.32 1,344 48

OC-192 9,953.28 (est)

5,376 (est) 192 (est)

NCFS Network Installation Terminology and Acronyms

• MPOE• DEMARC (extension)• Smart Jack• WIC• POE• Single-mode fiber vs. multi-mode fiber• More Telco Acronyms

MPOE

• Short for minimum point of entry, the closest practical point to where the cables of a telecommunications service carrier (i.e., a phone or cable company) cross a property line or where its wiring enters a multi-unit building. The MPOE of a multi-unit building is typically 12 inches inside the building’s foundation.

DEMARC

• In telephone networks, the demarcation point is the point at which the telephone company's local loop network ends and connects with the telephone system or wiring at the customer's premises. The DEMARC may be terminated on a 66 block, 110 block or a Smart Jack

66 Block 110 Block

Smart Jack

• A smart jack (also known as an NIU or Network Interface Unit) is a device that provides remote loopback capability so that intrusive bit error rate testing can be performed to help isolate trouble. Additionally, it is typically considered the demarcation point for service responsibility.

WIC

• A WAN interface card, or WIC, is a specialized network interface card (NIC) that allows devices to connect to a wide area network. A WIC has a built-in Channel Service Unit/Data Service Unit (CSU/DSU) interface that allows the card to communicate with a router that is connected to a WAN. This is where the T1 gets plugged into.

PoE

• Power over Ethernet or PoE technology describes a system to transmit electrical power, along with data, to remote devices over standard twisted-pair cable in an Ethernet network. This technology is useful for powering IP telephones, wireless LAN access points, webcams, Ethernet hubs, embedded computers, and other appliances where it would be inconvenient or infeasible to supply power separately.

Single Mode Fiber/Multimode FiberIn optical fiber technology, multimode fiber is optical fiber that is designed to carry multiple light rays or modes concurrently, each at a slightly different reflection angle within the optical fiber core. Multimode fiber transmission is used for relatively short distances because the modes tend to disperse over longer lengths

In optical fiber technology, single mode fiber is optical fiber that is designed for the transmission of a single ray or mode of light as a carrier and is used for long-distance signal transmission

Single Mode/Multimode Fiber

Fiber Connectors

Depending on the interface of the equipment, there are several fiber connector options available.

Telco Acronyms

• LEC/IEC• CO• PSTN/POTS• PBX• POP • SPID

LEC/IEC

• Local Exchange Carrier

• This could be Verizon, Sprint, or even AT&T depending upon the location.

• They are responsible for bringing the circuits in to the building.

• Their responsibility ends at the initial DEMARC or Smart Jack

• Inter Exchange Carrier

• AT&T

• “Long Distance” carrier handles interstate calls

CO• Central Office• Basically, it’s a

central point where all local voice and data runs through, then gets rerouted to the proper destination

PSTN/POTS

• Public Switched Telephone Network/Plain Old Telephone ServicePSTN (public switched telephone network) is the world's collection of interconnected voice-oriented public telephone networks, both commercial and government-owned. It's also referred to as the Plain Old Telephone Service (POTS). Today, it is almost entirely digital in technology except for the final link from the central (local) telephone office to the user.

There are digital conversions within the PSTN cloud, but at the 2 endpoints, it will always be analog

PBX• Private Branch Exchange• Connects to a pool of

local phone lines• Incoming and Outgoing

calls are routed to the first available line. The PBX then sends the call either to the intended user extension or out over the PSTN

• Most PBX systems today will use ISDN technology where you can have a pool of up to 23 phone lines over one ISDN-PRI

POP

• Point Of Presence. The local facility where your IEC maintains a switch. This is where your long distance calls get routed so that your IEC can handle them

• Sometimes the local phone company will rent or co-own space with the long distance company within it’s CO (i.e. Broad Street in Newark…Horse Hill Rd. in Cedar Knolls) to provide better service for both local and long distance

SPID• Service Profile Identifier- On

the "National ISDN", "AT&T Custom Point to Multipoint" and "Custom DMS" ISDN protocols, the Telco switch must receive correct SPID(s) from the CPE (customer premise equipment) before it will allow access to ISDN service. Intended to allow multiple configurations on ISDN lines shared among different types of CPE equipment.

Each ISDN channel will have a unique SPID which usually contains the ISDN phone number along with 2 additional numbers