Remote Connectivity
(PSTN) Public Switched Telephone Network or (POTS) Plain old telephone systems
Dial Up services: Customer pays on a per use basis (Analog Modem 56Kbps)
Modem converts Analog to Digital signals using an RJ11 connector
Internal Modem (PCI, ISA, AMR, PCMCIA, or integrated to the motherboard)
Modem converts Analog to Digital signals using an RJ11 connector
Internal Modem (PCI, ISA, AMR, PCMCIA, or integrated to the motherboard)
External Modem (USB or RS232 Serial COM)
Noise line, drivers and Call waiting can create havoc with modem connectivity
Noise line, drivers and Call waiting can create havoc with modem connectivity
external modem 
internal modem Modem manufacturers Hayes, 3COM/US Robotics, Diamond, Zoom
AT modem commands (Most Modem supports PPP and SLIP Protocols)
AT ok
ATA answer
ATD dial
ATDT dial tone
ATH hang up
ATZ reset
Other Internet connectivity
ATA answer
ATD dial
ATDT dial tone
ATH hang up
ATZ reset
Other Internet connectivity
DSL – Digital Subscriber Line is an Internet Access method that uses a standard phone line to provide high speed Internet access. (To get fast connection you must be close to the CO - central office)
Types of DSL – The most popular are the ADSL – Asymmetric most common and SDSL – Symmetric (business)
Types of DSL – The most popular are the ADSL – Asymmetric most common and SDSL – Symmetric (business)
DSLCable Modem – Coaxial broadband communication (Shared bandwidth)
Wireless Internet – Connecting to the Internet using wireless must subscribe to a Wireless Internet Service Provider
Wireless Internet – Connecting to the Internet using wireless must subscribe to a Wireless Internet Service Provider
cable modem Satellite – Uses satellite technology for Internet connection
satellite Packet vs. Circuit Switching Technology
Packet Switching – Technology that break messages into packets, each of which can take a different route through the network to the destination where packets are reassembled. So, in a packet-switched network, resources are not reserved and can take travel several routes through various routers
Circuit Switching – Technology that use a dedicated connection between receiver and sender when sending packets. Network resources are static before the start and until the end of data transfer, creating a logical circuit.
Switching Method Pros, Cons and Key Features
Packet Switching Packets can be routed around network congestion
Packet switching makes efficient use of bandwidth Packets can become lost while taking different routes to destination
Messages on packets contain information Packets can look for best path
There are 2 types of packet switching: datagram and virtual-circuit
Circuit Switching Offers dedicated transmission
Multiple devices have the capability to share bandwidth Dedicated channels can cause delays if it’s not available
The dedicated line between sending and receiving devices can have problems Offers the capability of storing messages temporarily to reduce network congestion
If you want to setup Internet connection in Windows follow the following steps:
Remote Access – Dial Up, Private Dial Up, VPN, Dedicated Connection
There are 2 types of packet switching: datagram and virtual-circuit
Circuit Switching Offers dedicated transmission
Multiple devices have the capability to share bandwidth Dedicated channels can cause delays if it’s not available
The dedicated line between sending and receiving devices can have problems Offers the capability of storing messages temporarily to reduce network congestion
If you want to setup Internet connection in Windows follow the following steps:
Remote Access – Dial Up, Private Dial Up, VPN, Dedicated Connection
Start>Programs>Accessories>Communication>New Connection Wizard
WAN Technologies CHART
WAN Technology Speed Supported Media Switching method Characteristics
ISDN- Integrated Services Digital Network
WAN Technologies CHART
WAN Technology Speed Supported Media Switching method Characteristics
ISDN- Integrated Services Digital Network
ISDNBRI - Basic Rate Interface 2B+ D Channels 64-128Kbps (home)
PRI – Primary Rate Interface 1.5Mpbs (business) Copper/Fiber optic Circuit Switching or
Packet Switching BRI uses 2B+D channels, PRI uses 23+D channels
ISDN uses the public network and requires dial up access
Packet Switching BRI uses 2B+D channels, PRI uses 23+D channels
ISDN uses the public network and requires dial up access
T-Connections
T-1 and J-1 1.5Mbps
E-1 2.048Mbps
T-3 44.736Mbps
T-3 44.736Mbps
E-3 34.368Mbps
J-3 32Mbps
E (Europe) and J (Japan)
Copper/Fiber Optic
Circuit Switching
T-carrier is used to create point-to-point network connections for private networks which is a dedicated lease line
Circuit Switching
T-carrier is used to create point-to-point network connections for private networks which is a dedicated lease line
FDDI – Fiber Distributed Data Interface
100Mbps Fiber Optic Dual Ring
Uses a dual ring configuration for fault tolerance. Uses a token passing media access method.
100Mbps Fiber Optic Dual Ring
Uses a dual ring configuration for fault tolerance. Uses a token passing media access method.
FDDIFrame Relay 56Kbps up to 44.736Mbps
(Fractional T1 or T3)
Copper/Fiber Optic Packet Switching
A packet-switching technology use for connecting devices on a WAN Frame Relay networks in the U.S. support data transfer rates at T-1 (1.544 Mbps and T-3 (45 Mbps) speeds
Frame RelayX. 25
56Kbps or 64Kbps
Copper/Fiber Optic Packet Switching
X.25 is an older technology that provides packet switching over standard phone lines
56Kbps or 64Kbps
Copper/Fiber Optic Packet Switching
X.25 is an older technology that provides packet switching over standard phone lines
ATM – Asynchronous Transfer Mode
155-622Mbps
Fiber Optic Packet Switching
Asynchronous Transfer Mode is considered best choice for mixing voice, video and data ATM uses fixed cells that are 53 bytes long
155-622Mbps
Fiber Optic Packet Switching
Asynchronous Transfer Mode is considered best choice for mixing voice, video and data ATM uses fixed cells that are 53 bytes long
ATMSONET – Synchronous Optical Network
sonetOptical carriers
OC-1- 51.85Mbps
OC-3 - 155.52Mbps
OC-12 - 622Mbps
OC-24 - 1.2Gbps
OC-48 - 2.4Gbps
OC-192 - 9.9Gbps
OC-255 - 13.21Gbps
OC-768 – 39.82Gbps
Fiber Optic
Point to Point
SONET defines synchronous data transfer over optical cable.
OC-3 - 155.52Mbps
OC-12 - 622Mbps
OC-24 - 1.2Gbps
OC-48 - 2.4Gbps
OC-192 - 9.9Gbps
OC-255 - 13.21Gbps
OC-768 – 39.82Gbps
Fiber Optic
Point to Point
SONET defines synchronous data transfer over optical cable.
The European and Asian equivalent of SONET is SDH (synchronous digital hierarchy)
