11/10/2010

1

Ing. Manuel Benitesg

7 Multiplexing7 Multiplexinga. Frequency division (FDM )b. Time division (TDM)c. Applications and hierarchies

8 El Modelo OSIa  Architecture and layers of the modela. Architecture and layers of the modelb. Functions and interconnection of layers

11/10/2010

2

Multiplexing categories

7 Multiplexing

7 Multiplexinga. Frequency division (FDM)

11/10/2010

3

7 Multiplexinga. Frequency division (FDM )

7 Multiplexinga. Frequency division (FDM)

FDM is a multiplexing technique that combines analog signals.

11/10/2010

4

FDM Process

7 Multiplexinga. Frequency division (FDM)

Example of FDM multiplexing

7 Multiplexinga. Frequency division (FDM)

11/10/2010

5

7 Multiplexingb. Time division (TDM)

7 Multiplexingb. Time division (TDM)

TDM is a digital multiplexing technique for combining several low‐speed channels into one high‐capacity channel.

11/10/2010

6

Synchronous TDM multiplexing

7 Multiplexingb. Time division (TDM)

Figure 3-37

7 Multiplexingb. Time division (TDM)

Synchronous TDM multiplexingy p g

11/10/2010

7

7 Multiplexingb. Time division (TDM)

In the synchronous TDM, the data rate of the link is n times faster, and the unit of duration is n times shorter.

Figure 3-39

Asynchronous TDM

7 Multiplexingb. Time division (TDM)

11/10/2010

8

7 Multiplexingc. Applications and hierarchies

Analog hierarchy

7 Multiplexingc. Applications and hierarchies

11/10/2010

9

8  The OSI Model8  The OSI Modela. Architecture and layers of the modelb. Functions and interconnection of layers

EstablishedEstablished inin 19471947 thethe InternationalInternational StandardsStandards

8 The OSI Modela. Architecture and layers of the model

EstablishedEstablished inin 19471947,, thethe InternationalInternational StandardsStandardsOrganizationOrganization (OSI)(OSI) isis aa multinationalmultinational organizationorganizationconcernedconcerned withwith attainingattaining agreementagreement onon internationalinternationalstandardsstandards..

AnAn OSIOSI standardstandard thatthat coverscovers allall aspectsaspects ofof networknetworkpp ffcommunicationscommunications isis thethe OpenOpen SystemsSystems InterconnectionInterconnectionmodelmodel.. ItIt waswas thethe firstfirst modelmodel introducedintroduced inin thethe 19701970ss..

11/10/2010

10

8 The OSI modela. Architecture and layers of the model

The OSI seven‐layer model

ISO model – Interaction between layers

8 The OSI modela. Architecture and layers of the model

11/10/2010

11

An exchange using the ISO model

8 The OSI modelb. Functions and interconnection of layers

Physical layer

8 The OSI modelb. Functions and interconnectin of layers

11/10/2010

12

8 The OSI modelb. Functions and interconnection of layers

The physical layer is responsible for the movement of individual bits from one node (hop) to the next

Data link layer

8 The OSI modelb. Functions and interconnection of layers

11/10/2010

13

8 The OSI modelb. Functions and interconnection of layers

The data link layer is responsible for moving frames from one hop to the next.

Hop-to-hop delivery

8 The OSI modelb. Functions and interconnection of layers

11/10/2010

14

Network layer

8 The OSI modelb. Functions and interconnection of layers

8 The OSI modelb. �Functions and interconnection of levels

The network layer is responsible for delivering individual packets from the source host to the destination host.

11/10/2010

15

Source – destination delivery

8 The OSI modelb. Functions and interconnection of layers

Transport layer

8 The OSI Modelb. Functions and interconnection of layers

11/10/2010

16

8 The OSI modelb. Functions and interconnection of layers

The transport layer is responsible for delivering a message from one process to another.

Reliability in message deliveryProcess - process

8 The OSI modelb. Functions and interconnection of layers

11/10/2010

17

Session layer

8 The OSI modelb. Functions and interconnection of layers

8 The OSI modelb. Functions and interconnection of layers

The session layer is responsible for dialogue control and syncronization.

11/10/2010

18

Presentation layer

8 The OSI modelb. Functions and interconnection of layers

8 The OSI modelb. Functions and interconnection of layers

The presentation layer is responsible for translation, compression and encryption

11/10/2010

19

Application layer

8 The OSI modelb. Functions and interconnection of layers

8 The OSI modelb. Functions and interconnection of layers

The application layer is responsible for the provision of services to the user.

11/10/2010

20

Summary of layers

8 The OSI modelb. Functions and interconnection of layers