 Hello everyone, welcome to the session on talent options, learning outcomes. At the end of the session students will be able to describe the concept of options and sub-option negotiation right. Students will be able to state the concept of controlling the server, content, option, sub-option negotiation, symmetry, sub-option negotiation, controlling the server. These are the topics I am going to cover in this video about talent option. Option is a part of talent. In the previous video we have discussed about what is talent, different types of logins where we have to use the concept of talent and types of talent and the types of logins, local login and remote login, how to use and then where we have to use, we have discussed in the last video. In this video we have discussed about the next part of talent that is talent option. Talent option is an option, is an extra space available to the user to add any extra space in the given packet or segment. Because with simpler terminal can use default features, the types of options are there. Here there are so many options we have to use while transmitting the data from one user to the another user. What are the different options types are there? This is the table can contain some of the options that are, if the table can contains code, option and meaning why we have to use, what is that option? Here the code are 0, code is 0 and then option is binary, it can be used to interpret 8 bit binary transmission. Next code is 1, echo and then it echoes the data issued on the one side of the other. And next suppress, go ahead, status is there and then timing mark, that code is 24 and terminal type, set the terminal type and these are the different options are there and then 32 is a code and then option type is in terminal speed and set the terminal speed while transmitting the data from one user to the another user and then code is in 34 and then option is in line mode, change to line mode. The different modes are there, default mode, character mode, line mode. Here we have to change from one mode to another mode, we have to use the option type is in line mode. In detail we will study about the different types of modes. The first one is binary, it allows the receiver to interpret every 8 bit character issued data. The second one is just it can echoes the whatever the data we have issued from the client or in the server side it can display the client data, in the client side it can echo the receiver issued data. Next one is suppress, go ahead, this option suppresses the whatever the data they want to transfer, yes we have to use the suppress, go ahead to transfer the data to the next user. Next one is status, it allows the process running on the client machine to get the status, how much data is already transferred and then how much data we want to transfer that we have to get in the status part. Next one is terminal timing mark, it means before transmitting the data the user should how to mark the timing, how much time it will takes to reach the data to the destination, it means it allows one party to issue a timing mark. Next one is terminal type, it allows the client to send its terminal type, it means whether the client is using what type of operating system, whether the user is using Unix operating system or Lough operating system or Linux operating system that we have to define in a terminal type. Next one is terminal speed, here we have to check out the speed of the data before transmitting, we have to fix the data then approximately the server can wait only limited amount of time, the data should be reached to the destination within that prescribed time, that is terminal speed, that is line mode, it allows the client to switch to the line mode from default mode. Next option negotiation, to use any of the options mentioned in the previous section first requires option negotiation between the client and server, option negotiation it means how much time and then operating system, everything we have to check out and then plus or minus we have to negotiate the data transmitting and receiving. Four control characters are used for this purpose, that a character code meaning one, meaning two and meaning three, it means it can however we are going for different character mode it can use a different meaning that characters will do don't, these are the four characters we have to use in the option negotiation and then code will 251 code we have to use offering to enable and then meaning to accepting to enable and then third option is meaning is not there and then won't 252 is code rejecting to enable offering to disable and accepting to disable the connection, do 253 is an code approving to enable requesting to enable don't 254 disapproving to enable, disapproving to disable and requesting to disable. These how these characters can works in detail we will study in the next video, this is the NVT character set for option negotiation. Here first one is enable enabling an option and enabling option is enabled either through offer or request, how it can offer to enable a party can offer to enable option the offering can approving a disapproved by the other party it means here sender can send the two characters first one is will and do or don't it means will after sending the client request the server can so I will enable the option and then he can reply I do enable the option or don't enable the option the server can reply to the client for data connection offer to enable an option here request to enable a party can requesting from the other party to enabling enabling of an option it means the client can send or sender machine can send the request do enable the option and the server can reply I will enable or I won't enable both if the user want to enable he can send the request I will enable either he don't want it means he can he won't enable the or I won't enable the option like this they can send the response to the client. Next one is disabling an option to an option that has been enabled can be disabled by one of the parties it means offer to disable a party can offer disable an option the other party must approve the offering it cannot be disapproved it means here is also the client can send the won't I won't use the option anymore then that time receiver can send I don't use it it means I don't directly they can close the option or communication offer to disable an option if client don't want to communicate with the server the server can reply don't use the don't continue to the communication or connection then that time they can disable the connection here next one is request to disable a party can request from another party the disabling of of an option it cannot be rejected it means they must have to disable the connection it means sender can send the don't use the option anymore then that time the server can reply I won't it means they can disable the connection from client and server next thing kind of it can contains one question what is an option described with an example now pass the video and answer the above question now answer for the next question is option is an option options are extra features available to user with a more sophisticated terminal okay the example the client wants the server to echo each character send to the server it means this client is sending some data to the server the data should be echoed to the server side how it can it means the client can send the do enable the echo option here we have to use the echo command do command and IAC IAC is an interpret as a character and then after sending this one the data will goes to the server side the server can reply echo will IAC IAC is an special combination of characters used to display the data in the both sides it means here they have to use echo do enable and then IAC and then in the receiver side the receiver have user echo I will enable and then it can disable display the data in the client side okay I will enable the echo option it means whatever the data is sent by the users that can echo in the client side as well as server side when it can display in the client side means after sending the data from the server side okay this is an echo option symmetry one interesting features of talent is its symmetric option negotiation in which the client and server are given equal opportunity it means both client and server have a equal weightage in a communication it means if while transmitting the data from client to the server and server to the client both the user should be active if any one user is don't want to communicate then that time automatically the whole communication will be disconnected at the beginning of connection it is assumed that both sides are you using a default talent implementation to options enabled okay and then sub-option negotiation some options require additional information that our character decimal binary and then meaning s e and then s e is an uh sub-option end and sub-option beginning for that we have to use a decimal 214 250 then this is a binary value of these values okay symmetry sub-option negotiation example defines the type speed of the terminal the option negotiation includes a string number to define the type of type or speed okay here just in the example how we how to the client our terminal type will i s e and then do enable terminal option and then here terminal type i will i s e and then here do enable terminal option i s e do and then terminal type and then at the end both side we have to use the symmetry character that is s e and s b sub-option end and sub-option beginning and then i s e tv terminal type and i s e is a terminal virtual and then i s e interpret as a control and terminal type we have to mention and then both the users they can display the data in both the side that is uh symmetry that is both client and server how equal weightage okay these are the references I have referred for preparing the above ppt thank you