Thought For The Week
No Question Is A Bad Question!
Key Point
T-Carriers Are A Primary Means Of
Point-To-Point Network Connectivity.
T-carriers Have Existed In The
Telecommunications Industry For
Quite Some Time.
At The End Of Lesson 4, You Should Be
Able To:
Describe The Differences Between T1, FT1,
And Digital Signal Level 3 (DS3) Systems
List Applications That Use T1, FT1, And DS3
Technologies
Digitizing Voice
Digital Voice Transmission Offers Several
Advantages:
Digital Signals Are Less Susceptible To
Interference; It Is Easier To Distinguish Noise
From Signal.
Binary Patterns Can Be Reproduced Exactly,
And “Cleaned Up,” When They Pass Through
Switches, Multiplexers (Muxs), Or Repeaters.
Digital Voice Signals Can Be Multiplexed With
Other Digital Data.
T-Carriers
T-carrier Rates Are Shown In The T-Carrier
Rates Table.
Standard
Line Type
Number of
Voice Circuits
Bit Rate
DS0
N/A
1
64 Kbps
DS1
T1
24
1.544 Mbps
DS1C
T1C/D
48
3.152 Mbps
DS2
T2
96
6.312 Mbps
DS3
T3
672
44.736 Mbps
DS4
T4
4032
274.176 Mbps
North America
T-Carriers
Standard
Line Type
Number of
Voice Circuits
Bit Rate
E1
M1
30
2.048 Mbps
E2
M2
120
8.448 Mbps
E3
M3
480
34.368 Mbps
E4
M4
1920
139.264 Mbps
E5
M5
7680
565.148 Mbps
Europe
T-Carriers
Standard
Line Type
Number of
Voice Circuits
Bit Rate
1
F-1
24
1.544 Mbps
2
F-6M
96
6.312 Mbps
3
F-32M
480
34.064 Mbps
4
F-100M
1440
97.728 Mbps
5
F-400M
5760
397.20 Mbps
6
F-4.6G
23040
1588.80 Mbps
Japan
T1
T1 Circuits Are Dedicated Services
Connecting Networks Or LANs Over
Extended Distances.
The Sample T1 Configuration Diagram
Presents a Typical Configuration.
Sample T1
Configuration
T1
As With A DDS Circuit, We Lease A T1 Circuit
Between Two Locations.
The DS-0 Network Diagram Demonstrates This By
Showing A Typical Four-Office Telephone Network
Built Using Individual DS-0 Lines.
DS-0 Network
T1
The T1 Network Diagram Demonstrates A Way
To Consolidate Interoffice Communications Into A
Single Backbone Consisting Of Four T1 Lines,
Capable Of Meeting Changing Traffic Demands
On The Fly.
T1 Network
T1
The T1 WAN Diagram Illustrates A Typical T1Based WAN.
T1 WAN
T3 And North American Digital Hierarchy
The North American Digital Hierarchy Is Created
Using A Series Of TDMs As Shown On The North
American Digital Hierarchy Diagram.
North American Digital Hierarchy
Circuit Costs
Lower T1 Circuit Costs Are Enabling More
And More Companies To Carry BandwidthIntensive Applications.