This document provides an overview of real time messaging technologies like instant messages, video calls, and group calling. It discusses basic instant messages, advanced features like video calling and group chats. It explains how instant messaging works by comparing it to models like email and Skype. The document provides guidance on using instant messaging safely, including using reputable providers and exercising caution when receiving attachments or sharing personal information. Overall, the document serves as an introduction to real-time communication technologies and offers tips for secure usage.

1. Follow the course on the
web at wingvillagehall.club
1

2. 2

3. Session 4
Real Time Messaging
Instant Messages
Free Phone Calls
Video Phone Calls
Group Calling
3

4. Introduction
tell you “Click X to do Y“
teach you step-by-step how to send
an email/Skype your son/etc
advise you on the best computer
etc…
4
Why Not?
Because nobody can remember that stuff
It will be different next week
Everyone’s needs are different
“I can’t be bothered with all this medical
stuff, show me how to do brain surgery”
These Sessions Will Not:

5. Introduction
Show you HOW to be comfortable with
new technologies
Show you WHY the new ways may be
advantageous for you
Help overcome the fear
Accept change
By
Explaining the jargon
Introducing the concepts
Getting you to think “Oh, this is like…”
Showing you can’t “break” a computer…
usually
These Sessions Will Try to:
5

6. What are basic Instant Messages?
• Real time i.e. you send it now,
your “target” sees it now.
• Like mobile phone Text - but
free and on a computer
• Short text messages… but often
there is no limit on message size
• Usually 1:1
• It can be a conversation
• Usually provide “Presence
Awareness”
• Both sides of the conversation
need to use the same protocol

7. What are advanced Instant Messages?
• You can also talk with your
“target” - usually for FREE
• With some IM systems you can
also see the “target” LIVE. It’s
a VideoPhone!
• Usually 1:1
• Sometimes you can send and
receive files i.e. photos,
documents
• Both sides of the conversation
need to use the same protocol

8. What are advanced Instant Messages?
• You can have a conversation with several people at the
same time - its a Conference Phone
• Both sides of the conversation need to use the same
protocol

9. Other ISP
Their
Broadband
Modem
Your
Broadband
Modem
Their ISP
Backbone Network
Your ISP
How does email work?
Domain
Name
Server
Mail
Server
Relay
Server
Mail
Server
Other ISP
ISP - Internet Service Provider
Your
email
app
It’s “Store and Forward”
It’s “Store and Forward”

10. Your
Broadband
GooglePlex
Backbone Network
Your ISP
How does Google work?
Domain
Name
Server
Mail
Server
Relay
Server
Search
Engines
It’s “Conversation” oriented
Request
Response

11. Harry’s
Modem
Sally’s
Modem
How does Instant Message work?
ISP - Internet Service Provider
to:harry
It’s “Store and Forward”34.73.46.10
It’s “Client Server” oriented
IM Server
IM
Name
Server
IM
Session
Server
Relay
Server
Relay Server
Relay
Server
Relay
Server
Relay
Server
IM
Server
Relay Server
Relay Server
Relay Server
Relay Server
Relay Server

12. Harry’s
Modem
Sally’s
Modem
IM Directory
How does Skype work?
ISP - Internet Service Provider
to:harry
It’s “Store and Forward”
Sally (moonpie)
Harry (hunkie)
34.73.46.10
It’s “Peer-to-Peer” oriented
IM
Name
Server
IM
Session
Server
Relay
Server
Relay Server
Relay
Server
Relay
Server
Relay
Server
IM
Server
Relay Server
Relay Server
Relay Server

13. Domain Names
International Company for Assignment
of Network Names (ICANN) assigns the
addresses to Domain Names
• e.g.
• google.com
• gmail.com
• bbc.co.uk
• facebook.com
• Registered with ICANN
• ANYONE can have a Domain Name
(from £2 - £100000+ a year)
• Each Domain can have lots of Servers
• Each Server can have several Hosts
i.e. Apps that provide a service
8 Main St
Wing
UK
LE15 8SE
HQ
BBC
CO.UK
212.58.246.000
www.bbc.co.uk/iplayer
www.bbc.co.uk/sport
www.bbc.co.uk/weather
www.bbc.co.uk=212.58.246.129
news.bbc.co.uk=212.58.246.81
Snail Internet
www.bbc.co.uk/news/england

14. The Internet as a House

15. Domain Name Server
(DNS)
I never use the address for
anything, I use a name.
• Your computer goes to a
DNS server
• It keeps a list of names and
corresponding IP addresses
• It tells your computer what
IP address to use

16. • All devices have a unique
address
• like a serial number - the
Media Access Code (MAC).
• Usually found on the bottom
or back of the device
• Defined by manufacturer
• e.g. 7A:79:19:73:D2:05
Media Access Code (MAC)

17. The Internet has a special networking
language - the Internet Protocol
Anyone who wants to use the
Internet has to have an address -
the Internet Protocol (IP) address
• Google is 31.55.163.183
• The BBC is 212.58.246.104
• First part defined by the
Internet Corporation for
Assigned Names and Numbers
(ICANN) e.g. Google 31, BBC
212 ( for big companies).
• The rest is defined by the
requesting company

18. The Internet

19. The Internet - a network of computers
So to put a server on the Internet you:
1. buy a Domain name from an ISP
• wingvillagehall.club
2. ISP sends details to ICANN
3. ICANN assigns an IP address
• e.g. wingvillagehall.club has address
65.39.140.84
4. ISP adds name/address pair to its DNS
server.
5. DNS entry is propagated around the
world to all other DNS servers

20. Instant Message Protocols
Its better if we both speak the
same “language”
AIM America On Line
Gtalk Google
ICQ mail.ru
Windows Live Messenger
Yahoo! Messenger
Jabber
Facebook Chat
Skype

21. Instant Message Apps
Client Apps
• installed on your computer
Skype
Google Hangout
AOL Instant Message (AIM)
Yahoo IM
…….
Web Apps
• Nothing installed on your computer
• messages STORED on a server
• lose computer, get another one and carry on
Google Hangout
AIM Express
ChatAB

22. Most IM systems are client-server
IM apps are often called
IM Clients - because the
client is used to connect
to a server
Just like eMail
Skype is Peer-to-Peer

23. What is Peer-to-Peer?
There is NO server! Each computer is
equal to every other computer.
Each computer has a list of the
computers DIRECTLY connected to it.
If the address is one of the links it uses
it. If not it just sends the message to
any one of the others.

24. Is Instant Message “safe”?
Used properly and with some
caution, YES
Used without some thought and
care, NO

25. Rules!
1.Use a reputable IM provider
They filter out most bad stuff, SPAM, before you see it
e.g. xxx@gmail.com
yyy@exchange.com
zzz@zoho.com
2.Do NOT use a cheap unknown IM provider
e.g. xxx@cheapemail.ru
3.NEVER open an attachment from someone you don't know
4.NEVER give your password to anyone on line or telephone
5.NEVER give credit card details unless it is httpS://xxxxx in
the address bar and then ONLY if you recognize the domain
Why? Because the bad guys will attack well-known domains
because more people are using them. They are unlikely to know
your private domain.

26. More Rules!
1.Always install an anti-virus app on
Windows PCs
Set it up to scan at least once a week
AVG
Avast
2.Always install an anti-malware app
Set it up to scan at least once a week
Malwarebytes
3.Open source apps are FREE and safer
Open source programs are written by
enthusiastic nerds who are volunteers and
passionate. There will be hundreds of
nerds checking the app for anything evil.

27. I don’t want ANYONE to
see my messages
Too bad!
Always assume that government agencies MAY
be reading.
For most normal, law-abiding citizens you CAN
keep your messages away from prying eyes
Skype encrypts all messages
but for telephone calls, only to receiving
exchange server
Many other IM protocols now support “Off The
Record” conversations (OTR)
WWII Enigma messages can all be decoded in
under a minute with a PC

28. The Internet
Part 1
Millions of computers
interconnected with a
common “language”

29. Questions?
About today
Still unanswered
Anything else
21

30. Follow the course on the
web at wingvillagehall.club
22