Transcript Internet Service Provider

Internet Hardware
• Connected ‘Servers’
• Servers provide:
– Web pages
– Email
– File downloads
Internet Hardware
• How do you plug into the internet?
Connect to the
telephone or cable
Your computer is called a client
(you pay to access the internet)
The clients connect
to a router
Internet
access
achieved!
Other devices in your house
are also called clients
Most routers now have
modems built in
Internet Connection
Your computer is called a client
(you pay to access the internet)
Your Internet Service Provider (ISP) has a
Point of Presence (POP) to connect you to the
internet (often in the telephone exchange)
Network Access Point (NAP)
This is where 2 or more networks
connect together
This is too simple a diagram, there
are many more connections!
This is more like it…
Connection Methods
• Wireless (WiFi)
• Broadband (High bandwidth)
• Dial-up (Low bandwidth)
Wireless
Advantages
• Wireless access
point required (most
home routers now provide this)
• Doesn’t require
tricky cabling
• Can be used in any
place where there
is a signal
Disadvantages
• Security issues,
hackers don’t need
to be on premises
• May suffer from
interference (radio noise)
• May be blocked by
walls
• Can be slower
Broadband
Advantages
• Reliable connection,
doesn’t drop out
• Generally faster
Disadvantages
• Distance from POP
can affect speed
• Doesn’t always
achieve the ‘up to’
speed
• Can only be used in
fixed location (end of
the wire)
Dial-up
Advantages
• Can provide
connection through
telephone lines,
further away from
the POP.
Disadvantages
• Slow… measured in KB not MB!
• Cannot make
phone calls when in
use
Internet - Protocols
•
•
•
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•
TCP (Transmission Control Protocol)
IP (Internet Protocol)
FTP (File Transfer Protocol)
SMTP (Simple Mail Transfer Protocol)
POP3 (Post Office Protocol) – Not point of presence, a
term you also need to know but one to do with ISPs!
TCP/IP Work together
TCP
IP
• Organises data being sent and
received over a network
• Breaks data into packets
• Labels the packets with address
details (sender and destination)
• Address is used by routers and
switches to get the packet to the
destination.
• Reassembles packets into correct
order
• Asks for any ‘lost’ packets to be
sent again
A 12 minute guide: https://www.youtube.com/watch?v=n7mtJ3ZV6xM
eMail
2. Using the SMTP protocol,
you send it to your ISP’s server
4. It waits on his ISP’s server until…
3. Your ISP sends it to his ISP
1. You type an email to your friend.
5. He connects and downloads his emails
using the POP3 protocol