“REMOTE FRAME BUFFER PROTOCOL PPT SEMINAR FREE DOWNLOAD

 

Introduction

RFB (remote framebuffer) is a simple and efficient protocol which provide remote

access to graphical user interfaces.As its Name Suggests it works at the framebuffer

level and thus it is applicable to all windowing systems and applications. Eg. X11,

Windows and Macintosh. It should also be noted that there are other Protocols available

and RFB is the protocol which is used in Virtual Network Computing (VNC)

and its various forms. Due to increase in number of Software products and Services

such protocols play a very important role nowadays.

Figure 1.1: Working of VNC

1.1 Basic Parts Of RFB Protocol

Display Protocol - the display part of the protocol is based on a simple idea. It is

actually based around a single graphics primitive: put a rectangle of pixel data at a

given x,y position.

Input Protocol - based on a normal workstation model of a keyboard and multibutton

pointing device. Every keypress and mouse events and transferred and simulated

at the remote site.

1.2 Features of RFB

RFB protocol specifies the rules for communication between 2 entities RFB client

and RFB server. In Current versions it supports multiple Clients also.RFB is truly a

thin client protocol. The emphasis in the design of this protocol is to make a client

with very less requirements. Thus,Clients can run on widest range of hardware, and

the task of implementing a client is made very simple RFB protocol makes the client

stateless.

RFB protocol gained significance after it was used in VNC (Virtual Network Computing)

and is very popular protocol nowadays RFB protocol is Open unlike many

other Remote Access Protocols.

1.3 Organization Of the Report

1. Chapter 2 describes the Representation of Pixel Data and Protocol Extensions

2. Chapter 3 Introduces the Various Protocol Messages

3. Chapter 4 describes the Handshaking Messages and Security Types

4. Chapter 5 describes Initialisation Messages

5. Chapter 6 describes Client to Server Messages

6. Chapter 7 describes Server to Client Messages

7. Chapter 8 describes Various Encodings

8. Chapter 9 shows Protocol Implementation

9. Chapter 10 is the conclusion

Chapter 2

REPRESENTATION OF PIXEL

DATA

The Interaction between server and client begins with a negotiation of the format and

encoding which will be used to send the pixel data. This step is included to make the

job of client easy. The server must always be able to supply the pixel data in the form

the client needs. In case the client can handle different formats,client can choose any

one it wishes. That is why this protocol is called a thin-Client Protocol.

Pixel Format refers to the representation of various individual colors by pixel values.

The most common formats are 24-bit or 16-bit where bit-fields translate directly

to the primary colors , and 8-bit color map where a mapping can be used to obtain

RGB intensities.

Encoding refers to how a rectangle of the above said pixel data will be sent across

the channel. Every triangle of this pixel data is prefixed by a header which contains

the X,Y position of the rectangle on the screen,the width and height of this triangle,

and an encoding type which specifies how the pixel data is encoded. In practice

we normally use only the ZRLE, Hextile and CopyRect encodings since they provide

the best compression as far as typical desktops are concerned.