Internet Services

What levels are there to ISDN?

Basic/Primary Rate Interface-a digital service, over a switched network BRI- (3 channels) -2 64 Kbps data channels 1 16 Kbps control channel PRI-(24 channels) up to 23 64 Kbps data and 1 64 Kbps control channel

What is Satellite Connection?

Requires line-of-site access to satellite. (suffers high latency) Early use was sat of down modem for up. Current dish for both up/down

Why do Satellite connections suffer high latency?

The distance the signal has to travel can be up to 1 second or more from computer to satellite and then back to the computer

What is Cable Internet?

The signal is brought by coax in using TV channel lines to transmit data to the cable modem.

How does DSL work

Transmits digital and voice signals over the phone line. Uses a form of multiplexing where-DSL >3.4KHz Voice <3.4KHz

What is Cellular Networking?

Using a cellular phone signal to access the internet from. This can be done using a cellular adapter or hotspot to provide internet access, as opposed to hooking the phone up to the computer directly.

In general how do you connect to the internet?

from device to access point, access point to ISP which then connects to the internet

What hardware is required to connect by Satellite?

Nic or modem to dish, dish to satellite (may be restricted to downloads only) if restricted you need a modem connection (phone/DSL)

What hardware is required to connect by dialup?

A modem and UTP RJ11, where your modem calls out to a modem at the ISP to establish a connection

What are the two types of DSL?

ADSL(Asymmetric) -Upload rate is throttled (cheaper) SDSL (symmetric)- Upload and download rate is the same

What device converts digital to analog, then analog to digital?

A modem- (modulator/demodulator)

What is Meshed Wireless?

A network with many wireless access points interconnected (meshed) to provide a network

What are the levels of Cellular networks?

2G- second gen-offered 14.4 Kbps 3G-third gen-offered simultaneous voice/data 2Mbps 4G-fourth gen-(WiMax) minmum speeds of 3-8Mbps (can be faster)

What hardware is required to connect by DSL?

A DSL router or interface card to connect to the phone line by UTP and RJ11, to the switch moves the digital data onto the digital network to the ISP

What hardware is required to connect by ISDN?

A NIC or router using UTP and RJ45 to ISDN network out to ISP(like DSL may need to contract with both phone and ISP)

What hardware is required to connect by Fiber?

A NIC to the box(eithernet or UTP-RJ45) to fiber, fiber to backbone and then backbone out to ISP (may need to contract seperately with ISP)

What hardware is required to connect by Cable?

A NIC to the modem then Coax cable with F-type connectors to the Cable company then out to ISP (can deal directly with company)

What hardware is required to connect by Cellular?

Contract with wireless company for access-wireless card to cell tower(may need additional hardware/software) or can hook up phone via USB to access internet (tethering)

What is DSL?

Digital Subscriber Line

How does ISDN work?

Divides the phone line into multiple channels.

What is the PSTN?

Public Switch Telephone Network-Transmits signal over telephone network using 56 Kilo bits per second using a modem

What is the ISDN?

Integrated Services Digital Network-similar to DSL (common in Europe)

What is VoIP?

Voice over IP- sends voice phone calls using the TCP/IP protocol over digital data lines instead of phone (ex skype)