Network Services
Content
F0026
Network Services
allows for the sharing of network
resources
Files and Printing
Messaging – i.e. emails, chat, bulletin
boards
Web information
Network applications allow end-user to
interface and utilize the shared network
resources.
Network Services
* Property of STI
Page 1 of 33
F0026
Types of Network Services
End-user applications
services are access directly by end-users
i.e. web, mail, file, print, etc.
Utility applications
services that are utilized indirectly by endusers
use is triggered by an end-user applications
i.e. name resolution, address acquisition,
etc.
Network Services
* Property of STI
Page 2 of 33
F0026
File Services
service that allows exchanging of files
between hosts/users
Internet standard protocol is known as FTP
– file transfer protocol
specified in RFC 959
reliable protocol that uses TCP
• Data (actual file transfer) port number = 20
• Control (commands execution) port
number = 21
Network Services
* Property of STI
Page 3 of 33
F0026
FTP Session Port
Numbers
Network Services
* Property of STI
Page 4 of 33
F0026
An anonymous FTP
Session
Network Services
* Property of STI
Page 5 of 33
F0026
Print Services
service that allows remote printing – when
the printer is not locally connected
Internet standard protocol is known as LDP
– line daemon protocol
specified in RFC 1179
reliable protocol that uses TCP port
number 515
Network Services
* Property of STI
Page 6 of 33
F0026
LDP Session
Network Services
* Property of STI
Page 7 of 33
F0026
Web Services
service that allows end-user to browse
from information servers
Internet standard protocol is known as
HTTP – hypertext transfer protocol
specified in RFC 2616
reliable protocol that uses TCP port
number 80 by default
Network Services
* Property of STI
Page 8 of 33
F0026
Web Links
Hyperlink
linking information objects without
necessarily following a sequenced structure
Hypertext
information object linked through
hyperlinks
also known as hypermedia
may be in various format – text, image,
video, audio, etc.
Network Services
* Property of STI
Page 9 of 33
F0026
Web Pages
file that outlines a collection of nonhypermedia and hypermedia data
hypermedia information may be linked to
other web pages or URLs
written in codes known as HTML –
hypertext mark-up language
can be viewed or accessed through an
application called a web browser:
Internet Explorer
Netscape
Opera
Network Services
* Property of STI
Page 10 of 33
F0026
HTML Codes: Sample Web
Page
Network Services
* Property of STI
Page 11 of 33
F0026
Viewing the Sample Web
Page
Network Services
* Property of STI
Page 12 of 33
F0026
HTTP Session
Network Services
* Property of STI
Page 13 of 33
F0026
Mail Services
service that allows an end-user to send
and receive electronic mails
Internet standard protocol is known as
SMTP – simple mail transfer protocol
specified in RFC 2821
reliable protocol that uses TCP port
number 25
Network Services
* Property of STI
Page 14 of 33
F0026
SMTP Sessions
Network Services
* Property of STI
Page 15 of 33
F0026
Mail Retrieval Modes of
Operation
Online
Offline
mails remain stored in the mail server
access and manipulation of the mails is
done from the client computer remotely
mails are fetched and then stored locally
by the client computer
access and manipulation of the mails are
done locally
Disconnected
mails are temporarily copied within the
client computer
access and manipulation can be done
locally in the client computer
any changes due to manipulation can be
synchronized with the mail server
Network Services
* Property of STI
Page 16 of 33
F0026
Message Retrieval
Protocols
POP – Post Office Protocol
specified in RFC 1725 (POP version 3)
uses TCP port number 110
IMAP – Internet Message Access Protocol
specified in RFC 1730 (IMAP version 4)
uses TCP port number 143
Network Services
* Property of STI
Page 17 of 33
F0026
POP and IMAP Sessions
Network Services
* Property of STI
Page 18 of 33
F0026
Remote Login Facility
service that allows an end-user to access a
computer remotely
access is limited to executing commands
commands are native to the remote
computer’s environment
Internet standard is known as TELNET
specified in RFC 854
uses TCP port number 23
Network Services
* Property of STI
Page 19 of 33
F0026
TELNET Session
Network Services
* Property of STI
Page 20 of 33
F0026
A Sample TELNET
Dialogue
Network Services
* Property of STI
Page 21 of 33
F0026
Name Resolution Service
utility application used to retrieve the
assigned IP address for a domain name
Internet standard is known as DNS –
Domain Name Service
specified in RFC 1034
uses UDP port number 53
Network Services
* Property of STI
Page 22 of 33
F0026
Domain Names
identifiers used to distinguish domain
networks
labels are separated by “dots” - i.e.
sti.edu.ph
domain is an independent network that
observes rules and policies defined by
private organizations
stored as database entries within the DNS
Server
Network Services
* Property of STI
Page 23 of 33
F0026
Top-Level Domain (TLD)
Hierarchy
way to interpret domain names for
systematic database organization
Interpretation is parsing the name from
right to left – ex. sti.edu.ph
.PH: Top-Level Domain
.EDU: Sub-Domain
STI
Network Services
* Property of STI
Page 24 of 33
F0026
Types of TLD’s
Country-Code TLD:
two letters long, associated with a country
or independent territory – i.e.:
• Country: CA – Canada, JP – Japan, MY –
Malaysia, PH – Philippines, SE – Sweden
• Independent Territory: HK – Hong Kong
Generic TLD:
three letters long, associated with a class
of organization – i.e. .COM, .NET, .ORG,
etc.
Network Services
* Property of STI
Page 25 of 33
F0026
Generic TLD’s
TLD
Suffix
Description
COM
Intended for use by commercial organizations,
or companies
EDU
Intended for use by educational institutions
GOV
Intended for use by any kind of government
agency or institution within the United States.
Agencies or institutions of other countries can
only use their respective Country-Code TLD
INT
Intended for use by organizations setup by
international treaties
MIL
Intended for exclusive use of the United States
Military
NET
Intended for use by computer network service
providers
ORG
Intended for use by miscellaneous organizations
that do not fit in the other mentioned TLD’s
Network Services
* Property of STI
Page 26 of 33
F0026
DNS Hierarchy
Network Services
* Property of STI
Page 27 of 33
F0026
DNS Query
Network Services
* Property of STI
Page 28 of 33
F0026
DNS Session
Network Services
* Property of STI
Page 29 of 33
F0026
Network Management
service that allows for remote
management of the network, or individual
network components
Internet standard is known as SNMP –
simple network management protocol
specified in RFC 1157
uses UDP port number 161 and 162
Network Services
* Property of STI
Page 30 of 33
F0026
SNMP Model
Agents
Management Information Base (MIB)
small programs running in the background
that monitors the network device
network devices that are monitored can be
servers, hubs, switches or routers
file that is used by the agent within the
network device that outlines the
items/parameters that are being
monitored
Manager
application running in the client computer
that allows end-users to monitor,
configure, or operate remote network
devices
Network Services
* Property of STI
Page 31 of 33
F0026
SNMP Structure
Network Services
* Property of STI
Page 32 of 33
F0026
SNMP Session
Network Services
* Property of STI
Page 33 of 33
Network Services
allows for the sharing of network
resources
Files and Printing
Messaging – i.e. emails, chat, bulletin
boards
Web information
Network applications allow end-user to
interface and utilize the shared network
resources.
Network Services
* Property of STI
Page 1 of 33
F0026
Types of Network Services
End-user applications
services are access directly by end-users
i.e. web, mail, file, print, etc.
Utility applications
services that are utilized indirectly by endusers
use is triggered by an end-user applications
i.e. name resolution, address acquisition,
etc.
Network Services
* Property of STI
Page 2 of 33
F0026
File Services
service that allows exchanging of files
between hosts/users
Internet standard protocol is known as FTP
– file transfer protocol
specified in RFC 959
reliable protocol that uses TCP
• Data (actual file transfer) port number = 20
• Control (commands execution) port
number = 21
Network Services
* Property of STI
Page 3 of 33
F0026
FTP Session Port
Numbers
Network Services
* Property of STI
Page 4 of 33
F0026
An anonymous FTP
Session
Network Services
* Property of STI
Page 5 of 33
F0026
Print Services
service that allows remote printing – when
the printer is not locally connected
Internet standard protocol is known as LDP
– line daemon protocol
specified in RFC 1179
reliable protocol that uses TCP port
number 515
Network Services
* Property of STI
Page 6 of 33
F0026
LDP Session
Network Services
* Property of STI
Page 7 of 33
F0026
Web Services
service that allows end-user to browse
from information servers
Internet standard protocol is known as
HTTP – hypertext transfer protocol
specified in RFC 2616
reliable protocol that uses TCP port
number 80 by default
Network Services
* Property of STI
Page 8 of 33
F0026
Web Links
Hyperlink
linking information objects without
necessarily following a sequenced structure
Hypertext
information object linked through
hyperlinks
also known as hypermedia
may be in various format – text, image,
video, audio, etc.
Network Services
* Property of STI
Page 9 of 33
F0026
Web Pages
file that outlines a collection of nonhypermedia and hypermedia data
hypermedia information may be linked to
other web pages or URLs
written in codes known as HTML –
hypertext mark-up language
can be viewed or accessed through an
application called a web browser:
Internet Explorer
Netscape
Opera
Network Services
* Property of STI
Page 10 of 33
F0026
HTML Codes: Sample Web
Page
Network Services
* Property of STI
Page 11 of 33
F0026
Viewing the Sample Web
Page
Network Services
* Property of STI
Page 12 of 33
F0026
HTTP Session
Network Services
* Property of STI
Page 13 of 33
F0026
Mail Services
service that allows an end-user to send
and receive electronic mails
Internet standard protocol is known as
SMTP – simple mail transfer protocol
specified in RFC 2821
reliable protocol that uses TCP port
number 25
Network Services
* Property of STI
Page 14 of 33
F0026
SMTP Sessions
Network Services
* Property of STI
Page 15 of 33
F0026
Mail Retrieval Modes of
Operation
Online
Offline
mails remain stored in the mail server
access and manipulation of the mails is
done from the client computer remotely
mails are fetched and then stored locally
by the client computer
access and manipulation of the mails are
done locally
Disconnected
mails are temporarily copied within the
client computer
access and manipulation can be done
locally in the client computer
any changes due to manipulation can be
synchronized with the mail server
Network Services
* Property of STI
Page 16 of 33
F0026
Message Retrieval
Protocols
POP – Post Office Protocol
specified in RFC 1725 (POP version 3)
uses TCP port number 110
IMAP – Internet Message Access Protocol
specified in RFC 1730 (IMAP version 4)
uses TCP port number 143
Network Services
* Property of STI
Page 17 of 33
F0026
POP and IMAP Sessions
Network Services
* Property of STI
Page 18 of 33
F0026
Remote Login Facility
service that allows an end-user to access a
computer remotely
access is limited to executing commands
commands are native to the remote
computer’s environment
Internet standard is known as TELNET
specified in RFC 854
uses TCP port number 23
Network Services
* Property of STI
Page 19 of 33
F0026
TELNET Session
Network Services
* Property of STI
Page 20 of 33
F0026
A Sample TELNET
Dialogue
Network Services
* Property of STI
Page 21 of 33
F0026
Name Resolution Service
utility application used to retrieve the
assigned IP address for a domain name
Internet standard is known as DNS –
Domain Name Service
specified in RFC 1034
uses UDP port number 53
Network Services
* Property of STI
Page 22 of 33
F0026
Domain Names
identifiers used to distinguish domain
networks
labels are separated by “dots” - i.e.
sti.edu.ph
domain is an independent network that
observes rules and policies defined by
private organizations
stored as database entries within the DNS
Server
Network Services
* Property of STI
Page 23 of 33
F0026
Top-Level Domain (TLD)
Hierarchy
way to interpret domain names for
systematic database organization
Interpretation is parsing the name from
right to left – ex. sti.edu.ph
.PH: Top-Level Domain
.EDU: Sub-Domain
STI
Network Services
* Property of STI
Page 24 of 33
F0026
Types of TLD’s
Country-Code TLD:
two letters long, associated with a country
or independent territory – i.e.:
• Country: CA – Canada, JP – Japan, MY –
Malaysia, PH – Philippines, SE – Sweden
• Independent Territory: HK – Hong Kong
Generic TLD:
three letters long, associated with a class
of organization – i.e. .COM, .NET, .ORG,
etc.
Network Services
* Property of STI
Page 25 of 33
F0026
Generic TLD’s
TLD
Suffix
Description
COM
Intended for use by commercial organizations,
or companies
EDU
Intended for use by educational institutions
GOV
Intended for use by any kind of government
agency or institution within the United States.
Agencies or institutions of other countries can
only use their respective Country-Code TLD
INT
Intended for use by organizations setup by
international treaties
MIL
Intended for exclusive use of the United States
Military
NET
Intended for use by computer network service
providers
ORG
Intended for use by miscellaneous organizations
that do not fit in the other mentioned TLD’s
Network Services
* Property of STI
Page 26 of 33
F0026
DNS Hierarchy
Network Services
* Property of STI
Page 27 of 33
F0026
DNS Query
Network Services
* Property of STI
Page 28 of 33
F0026
DNS Session
Network Services
* Property of STI
Page 29 of 33
F0026
Network Management
service that allows for remote
management of the network, or individual
network components
Internet standard is known as SNMP –
simple network management protocol
specified in RFC 1157
uses UDP port number 161 and 162
Network Services
* Property of STI
Page 30 of 33
F0026
SNMP Model
Agents
Management Information Base (MIB)
small programs running in the background
that monitors the network device
network devices that are monitored can be
servers, hubs, switches or routers
file that is used by the agent within the
network device that outlines the
items/parameters that are being
monitored
Manager
application running in the client computer
that allows end-users to monitor,
configure, or operate remote network
devices
Network Services
* Property of STI
Page 31 of 33
F0026
SNMP Structure
Network Services
* Property of STI
Page 32 of 33
F0026
SNMP Session
Network Services
* Property of STI
Page 33 of 33
