617 skills found · Page 6 of 21
OPTIMUM-LINKUP / Latest Optimum School SystemThis is the latest school management system. Available for all type of schools. will work on Phone, Laptop, Tabs, monitors - any screen size. It is available with 100% source code. The features are listed below: INSTALLATION Upload the downloaded zip file to your server in the public_html directory. Extract the zip file. Create a new database from your server mysql. Create user to the database and link the database to the user. Open the file database.php from the directory yourfolder/application/config/database.php. Fill up this information with your database hostname, database username, database password, database name respectively which you have created in the previous step. Now from server phpmyadmin go to your database. Select import and choose the file install.sql located in yourfolder/database/blank_db.sql (demo_db.sql for demo database) And you are ready to go now to browse the application Default admin credentials Email: admin@admin.com Password: admin ADMIN PANEL Managing User accounts (teacher, student, parent) Managing classes, subjects Managing exam, grades Managing exam marks Managing Loan Information Managing Computer Based Test (CBT) Sending exam marks via sms Managing students attendance Managing accounting, income and expenses Managing school events Managing Teachers Managing Libratrian Managing Accountant Manage Circular Manage Task Managing Parents Managing Alumni Managing Academic Sysllabus Managing Helpful Links Managing Help Desk Managing Front-End Information Managing School Session Attendance Reports Managing Staff ID Cards Records management. Notification board management. Management relationships between different type of users. Online Payment acceptance of FEE. Section Management. Reports generator. SMS Alerts. Managing Hostel Manager Managing library, dormitory, transport Messaging between other users Managing system settings (general, sms, language) Managing Media Subject management. Class management. Student payments management. Student behaviour management. Payments Overview. Subjects and assignments management. Fees management. Student assignment results management. Student search. Overdue students list. Student management. Student-Teacher interaction. And many more … TEACHERS Manage Students homework. Assign homework. Share homework on social networking sites (facebook). Manage classes. Manage Student Report. Generate Remarks on Student Reports. Generate Student Attendence. Subject management. Loan Application Class management. Student behaviour management. Subjects and assignments management. Student assignment results management. Student search. Student management. Student-Teacher interaction. Managing Helpful Links Managing Media Assignments Attendance Provide Daily Quotes Holidays Studennts Study Materials Message Noticeboard Transportations And many more… STUDENT PANEL Get class Routine Attempt Online Exam View Online Exam Result Get Exam Marks Message View Noticeboard Transportatio Receive SMS Get attendance status Get study materials / files from teacher Get payment invoice, Pay Online Communicate with teacher Managing Media accounts View Event Schedule, Notice and Holidays Get Helpful Links View Daily Quotes Contact Help Desks And many more …. PARENT PANEL View Children Marks View Children Class Routine Make payment View Payment Invoice Message Admin Message Teachers View Received Messkages Checkin kids progress. Parent-Teacher interaction. Get alerts from School Administration or Teachers. View events Noticeborad Todays Thought News Helpful Links Help Desk Receive SMS And many more … LIBRARIAN Add books Update books Record Lost Books Generate Reports on Books Subject Management. Loan Application Student Search. Student Management. Student-Librarian Interaction. View Helpful Links View Media Holidays Studennts Study Materials Message Transportations Noticeboard View Notification And many more …. ACCOUNTANTS Create Student Payments Students Payment Expenses Expenses Category Vew all Accountants Loan Application Todays Thought News Holidays Message k Noticeboard And many more …. HOSTEL MANAGER ViewAll Hostel Managers Manage Hostels Loan Application Todays Thought News Holidays Message Noticeboard And many more …. ………………………………………………………………………………………………… ADMIN PANEL DASHBORD ………………………………………………………………………………………………… Total number of students, teachers, librarian, accountants, hostel manager, alumni, parents and attendance of students for that day at a glance, Dashboard also holds a calendar for showing events, charts for various percentages of teachers, parents, students attendance, grades, students performances, etc. MANAGING SESSION From navigation go to manage session Add / edit / delete MANAGING ACADEMIC SYLLABUS From navigation go to manage academic syllabus Add / edit / delete MANAGING MEDIA From navigation go to manage media Add / edit / delete MANAGING STUDENTS Admit Students From navigation, go to students > admit students Fill up the necessary information Save student Admit Bulk Students From navigation, go to student > admit bulk student Download the blank Excel file Fill up the information Select class Upload the filled up Excel file Save Student Information From navigation go to student > student information Here you can see the students class wise If a class has sections then you can also browse the students as per class sections Student mark sheets From navigation go to student > student mark sheet Here you can see all the students marks class wise If the class has sections then you can also see them along with class MANAGING TEACHERS From navigation go to teacher Here you can see the list of teachers of your school in a tabular form To add a new teacher, click the top right button named add new teacher and fill up the information and save For editing or deleting a teacher information click the action button assigned to each entry of the table. That will bring two options for editing and deleting. Click on the required action editing and deleting MANAGING ACCOUNTANTS From navigation go to accountant Here you can see the list of accountants of your school in a tabular form To add a new accountant, click the top right button named add new accountant and fill up the information and save For editing or deleting a teacher information click the action button assigned to each entry of the table. That will bring two options for editing and deleting. Click on the required action editing and deleting MANAGING LIBRARIANS From navigation go to librarian Here you can see the list of librarians of your school in a tabular form To add a new librarian, click the top right button named add new librarian and fill up the information and save For editing or deleting a teacher information click the action button assigned to each entry of the table. That will bring two options for editing and deleting. Click on the required action editing and deleting MANAGING HOSTEL MANAGERS From navigation go to hostel manager Here you can see the list of hostel managers of your school in a tabular form To add a new hostel manager, click the top right button named add new hostel manager and fill up the information and save For editing or deleting a teacher information click the action button assigned to each entry of the table. That will bring two options for editing and deleting. Click on the required action editing and deleting MANAGING ALUMNI From navigation go to alumni Here you can see the list of alumni of your school in a tabular form To add a new alumni, click the top right button named add new alumni and fill up the information and save For editing or deleting a teacher information click the action button assigned to each entry of the table. That will bring two options for editing and deleting. Click on the required action editing and deleting MANAGING PARENTS From navigation go to parents Here you can see the list of parents of the students of your school in a tabular form To add a new parent, click the top right button named add new parent and fill up the information and save For editing or deleting a parent information click the action button assigned to each entry of the table. That will bring two options for editing and deleting. Click on the required action for editing and deleting MANAGING CLASSES From navigation go to > manage sections Add new class section for a class and assign teacher for each of them View the class sections in a tabular form class wise Edit and delete class section information MANAGING CLASS SECTION From navigation go to class > manage sections Add new class section for a class and assign a teacher for each of them View the class sections in a tabular for class wise Edit and deklete class section information MANAGING SUBJECTS From navigation go to subject If you have already added classes then under this you will see a list of the classes added. If you have not created classes, please create class first Here you can see the subjects class wise Add or edit or delete subjects MANAGING CLASS ROUTINE From navigation go to class routine View all the class routines in accordion Add class routine Click on the subject name on routine to edit and delete MANAGING DIALY STUDENT’S ATTENDENCE From navigation go to daily attendance Select the date and class and click manage attendance That will bring up the students name and attendance information in a tabular form To update the attendance status or for taking the attendance for that particular date of that particular class which you have selected earlier, click the button named update attendance Put the status for all at once and click save changes MANAGING EXAMS Exam list From navigation, go to exam > exam list Add an exam for all Edit and delete exam Exam grade From navigation go to exam > exam grades Add exam grades as per the requirements of your institution Edit or delete exam grades Manage exam marks From navigation go to > manage marks Select exam, class and subject and click manage marks for changing or updating marks That will bring up the form for updating the students marks for that particular subject Enter the marks and click update Sending exam marks by SMS From navigation go to exam > send mark by SMS Select exakm and class and receive (students/parent) Click the button named send mark via SMS That will send SMS with the marks for that exam you have selected if a SMS service is already activated MANAGING PAYMENTS From navigation go to payment Add invoice and take manual payment multiple time under the same invoice If a payment is due, then an option will be there for taking the payment in the action button of the table that contains the list of all the invoices with the basic information. Edit or delete invoice LOAN MANAGEMENT From navigation go to loan application See all the applied loans Click on apply loan Fill forms to apply Wait for loan approval COMPUTER BASED TEST (CBT) From navigation, go to Manage CBT Click on Add Exam Set Class, Exam Time, Exam Duration, Subject, Question Count and Session Click on continue to Add Questions Click on List Exams to View Exams Click on View Result to View Exams Scores ACCOUNTING Incomes From navigation, go to accounting > incomes Here you can see all the incomes for your school that means students fee in a tabular form with their payment time and amount EXPENSES From navigation, go to accounting > expenses Add expenses for the school Edit or delete them GENERATING STAFF IDCARD Teacher, librarian, accounant, hostel manager From navigation, go to staff > ID CARD Here you can you will see a button asking you to click generate ID CARD EXPENSE CATEGORY From navigation, go to accounting > expense category Add expense category Edit or delete them MANAGING BOOKS From navigation go to library Add books Edit or delete them MANAGING TRANSPORT From navigation go to transport Add transport information Edit or delete them MANAGING DORMITORY From navigation go to dormitory Add / edit / delete MANAGING ASSIGNMENT From navigation go to assignment Add / edit / delete MANAGING HOLIDAYS From navigation go to holiday Add / edit / delete MANAGING TODAY’S THOUGHT From navigation go to today’s thought Add / edit / delete MANAGING CIRCULAR From navigation go to circular Add / edit / delete MANAGING SCHOOL CLUBS From navigation go to school club Add / edit / delete MANAGING TASK From navigation go to task manager Add / edit / delete MANAGING HELPFUL LINK From navigation go to Helpful Links Add / edit / delete MANAGING ENQUIRY From navigation go to enquiry Add / edit / delete MANAGING ENQUIRY CATEFORY From navigation go to enquiry category Add / edit / delete MANAGING HELP DESK From navigation go to task Helpdesk Add / edit / delete NOTICEBOARD From navigation go to notice board Add / edit / delete them For sending the notice to all as SMS, yes while creating the notice This will send SMS to all the users about that notice PRIVATE MESSAGING From navigation, go to message Admin can send message to all users For sending message, select user and type the message and click send You can also see all the message sent to you or sent from you SYSTEM SETTINGS From navigation go to settings > general settings You can change basic system settings here and also can select language You can also upload logo from here THEME SETTINGS From navigation go to setting > general settings On the right of the page there is a panel named theme settings You find several skin options for you application Select you desire one to make changes SMS SETTINGS From navigation go to settings > sms settings Here you will find 2 SMS services, one is Clickatell and another is Twilio You have to activate a service first Then put the necessary information for a service Visit https://www.twilio.com/user/acount/settings/international /sms LANGUAGE SETTINGS From navigation go to setting > language settings Change phrase or add new phrase for a particular language Add new language MANAGE BANNER SETTINGS From navigation go to setting > banner settings Add / edit / delete MANAGE FRONT END SETTINGS From navigation go to setting > front end settings Add / edit / delete MANAGE NEWS SETTINGS From navigation go to setting > news settings Add / edit / delete ACCOUNT SETTINGS From navigation go to account Change basic account information Update your password Change profile image ……………………………………………………………………………………………….. TEACHER PANEL DASHBOARD ………………………………………………………………………………………………. Total number of students, parents and attendance of students for that day at a glance Dashboard also holds a calendar for showing events. MANAGING STUDENTS Admit students From navigation go to student > admit student Fill up the necessary information Save student Student information From navigation go to student > student information Here you can see the student class wise If a class has sections then you can also browse the students as per class sections Student mark sheets From navigation go to student > student mark sheet Here you can see all the students marks class wise If the class has sections then you can also see them along with class MANAGING DAILY STUDENT’S ATTENDANCE From navigation go to daily attendance Select the date and class and click mange attendance That will bring up the students name and attendance information in a tabular form To update the attendance status or for taking the attendance for that particular date of that particular class which you have selected earlier, click the button named update attendance Put the status for all at once and click save changes MANAGING DAILY STUDENT’S ATTENDANCE From navigation go to daily attendance Select the date and class and click manage attendance That will bring up the students name and attendance information in a tabular form To update the attendance status or for taking the attendance for that particular date of that particular class which you have selected earlier, click the button named update attendance Put the status for all at once and click save changes MANAGING ASSIGNMENT From navigation go to assignment That will bring up the assignemnt page in a tabular form, you can click on add assignment on left corner of the page to add assignment. MANAGING CLASSES From navigation go to > manage sections Add new class section for a class and assign teacher for each of them View the class sections in a tabular form class wise Edit and delete class section information MANAGING CLASS SECTION From navigation go to class > manage sections Add new class section for a class and assign a teacher for each of them View the class sections in a tabular for class wise Edit and deklete class section information MANAGING SUBJECTS From navigation go to subject If you have already added classes then under this you will see a list of the classes added. If you have not created classes, please create class first Here you can see the subjects class wise Add or edit or delete subjects MANAGING CLASS ROUTINE From navigation go to class routine View all the class routines in accordion Add class routine Click on the subject name on routine to edit and delete MANAGING DIALY STUDENT’S ATTENDENCE From navigation go to daily attendance Select the date and class and click manage attendance That will bring up the students name and attendance information in a tabular form To update the attendance status or for taking the attendance for that particular date of that particular class which you have selected earlier, click the button named update attendance Put the status for all at once and click save changes MANAGING EXAMS Manage exam marks From navigation go to > manage marks Select exam, class and subject and click manage marks for changing or updating marks That will bring up the form for updating the students marks for that particular subject Enter the marks and click update MANAGING HELPFUL LINK From navigation go to Helpful Links Add / edit / delete NEWS From navigation go to view news View all the uploaded news TODAY’S THOUGHT From navigation go to today’s thought View all the uploaded today’s thought HOLIDAY DATES From navigation go to holiday View all the holiday with their respectives dates ……………………………………………………………………………………………………. STUDENT PANEL DASHBOARD ……………………………………………………………………………………………………. Total number of students, teachers, parents and attendance of students for that day at a glance, dashboard also holds a calendar for showing event CLASS ROUTINE Form navigation go to class routine View the class routine of the logged in student EXAM MARKS From navigation go to exam > manage marks Select exam and subject See the mark for the selected exam in the selected subject COMPUTER BASED TEST (CBT) From navigation go to online CBT See all the uploaded test for your class Attemtp the uploaded test View your results STUDY MATERIALS From navigation go to study materials See all the uploaded study materials for your class Download the materials ASSIGNMENT From navigation go to assignment See all the uploaded assignments for your class Download the assignment MEDIA From navigation go to media See all the uploaded media for your class Download or watch media NEWS From navigation go to view news View all the uploaded news TODAY’S THOUGHT From navigation go to today’s thought View all the uploaded today’s thought HOLIDAY DATES From navigation go to holiday View all the holiday with their respectives dates HELPFUL LINKS From navigation go to helpful links View all the helpful links HELP DESK From navigation go to help desk Submit or create help desk to the administrator STUDY MATERIALS From navigation go to study material See all the uploaded study material for your class Download the study material PAYMENT / PAY WITH PAYPAL From navigation go to payment See the list of invoices Pay online with paypal for the unpaid invoices COMMUNICATE WITH TEACHERS / ADMIN From navigation go to message Send new message to teachers and admin Get the sent message to you ………………………………………………………………………………………………...... ACCOUNTANT PANEL DASHBOARD ………………………………………………………………………………………………….. Total number of students, accountants, parents and attendance of student for that day at a glance. Dashboard also holds a calendar for showing events. MANAGING PAYMENTS From navigation go to payment Add invoice and take manual payment multiple time under the same invoice If a payment is due, then an option will be there for taking the payment in the action button of the table that contains the list of all the invoices with the basic information. Edit or delete invoice LOAN MANAGEMENT From navigation go to loan application See all the applied loans Click on apply loan Fill forms to apply Wait for loan approval MESSAGING From navigating go to message Send message to teachers and admin Get the message sent to you NEWS From navigation go to view news View all the uploaded news TODAY’S THOUGHT From navigation go to today’s thought View all the uploaded today’s thought HOLIDAY DATES From navigation go to holiday View all the holiday with their respectives dates HELPFUL LINKS From navigation go to helpful links View all the helpful links HELP DESK From navigation go to help desk Submit or create help desk to the administrator TRANSPORTATION From navigation go to transportation View transportation available ………………………………………………………………………………………………...... LIBRARIAN PANEL DASHBOARD ………………………………………………………………………………………………….. Total number of students, librarian, parents and attendance of student for that day at a glance. Dashboard also holds a calendar for showing events. MANAGING BOOKS From navigation go to library Add books Edit or delete them LOAN MANAGEMENT From navigation go to loan application See all the applied loans Click on apply loan Fill forms to apply Wait for loan approval MESSAGING From navigating go to message Send message to teachers and admin Get the message sent to you NEWS From navigation go to view news View all the uploaded news TODAY’S THOUGHT From navigation go to today’s thought View all the uploaded today’s thought HOLIDAY DATES From navigation go to holiday View all the holiday with their respectives dates HELPFUL LINKS From navigation go to helpful links View all the helpful links HELP DESK From navigation go to help desk Submit or create help desk to the administrator TRANSPORTATION From navigation go to transportation View transportation available ………………………………………………………………………………………………...... HOSTEL MANAGER PANEL DASHBOARD ………………………………………………………………………………………………….. Total number of students, hostel managers, parents and attendance of student for that day at a glance. Dashboard also holds a calendar for showing events. MANAGING DORMITORY From navigation go to dormitory Add / edit / delete LOAN MANAGEMENT From navigation go to loan application See all the applied loans Click on apply loan Fill forms to apply Wait for loan approval MESSAGING From navigating go to message Send message to teachers and admin Get the message sent to you NEWS From navigation go to view news View all the uploaded news TODAY’S THOUGHT From navigation go to today’s thought View all the uploaded today’s thought HOLIDAY DATES From navigation go to holiday View all the holiday with their respectives dates HELPFUL LINKS From navigation go to helpful links View all the helpful links HELP DESK From navigation go to help desk Submit or create help desk to the administrator TRANSPORTATION From navigation go to transportation View transportation available ………………………………………………………………………………………………...... PARENT PANEL DASHBOARD ………………………………………………………………………………………………….. Total number of students, teachers, parents and attendance of student for that day at a glance. Dashboard also holds a calendar for showing events. CHILDREN MARKS From navigation go to exam marks See the mark of your children individually One parent can have multiple children PAYMENTS From navigation go to exam > payment View the invoices of your children and individually Make payment via paypal online CLASS ROUTINE From navigation go to class routine Get the class routine for each of your child separately MESSAGING From navigating go to message Send message to teachers and admin Get the message sent to you NEWS From navigation go to view news View all the uploaded news TODAY’S THOUGHT From navigation go to today’s thought View all the uploaded today’s thought HOLIDAY DATES From navigation go to holiday View all the holiday with their respectives dates HELPFUL LINKS From navigation go to helpful links View all the helpful links HELP DESK From navigation go to help desk Submit or create help desk to the administrator
travisjeffery / TRVSEventSourceServer-sent events EventSource client using NSURLSession
Xingsandesu / CarrotAICarrotAI is a cutting-edge AI agent application that delivers real-time streaming chat via Server-Sent Events (SSE) with built-in Model Control Protocol (MCP) integration. It supports concurrent connections to multiple SSE MCP servers and provides user interfaces in English, Chinese, and Japanese.
render-examples / Go Gin Web ServerDeploy Go Gin on Render
axway-streams / Axway Amplify Streams JsAMPLIFY Streams Javascript package containing SDK, documentation and sample applications
roniemartinez / Real Time Charts With FlaskSample application for the blog "Creating Real-Time Charts with Flask"
triblondon / Node Sse PubsubServer sent events for NodeJS
benwilber / TinysseA programmable server for Server-Sent Events (SSE).
launchdarkly / Dotnet EventsourceServer-sent events (SSE) client implementation for .NET
niwinz / SseServer Sent Events protocol implemetation on python2/3
mariomac / JeasseJava Easy SSE (Server-Sent Events) implementation
MaxHalford / Flask Sse No DepsAn example of server-sent events in Flask without extra dependencies
SOYJUN / FTP Implement Based On UDPThe aim of this assignment is to have you do UDP socket client / server programming with a focus on two broad aspects : Setting up the exchange between the client and server in a secure way despite the lack of a formal connection (as in TCP) between the two, so that ‘outsider’ UDP datagrams (broadcast, multicast, unicast - fortuitously or maliciously) cannot intrude on the communication. Introducing application-layer protocol data-transmission reliability, flow control and congestion control in the client and server using TCP-like ARQ sliding window mechanisms. The second item above is much more of a challenge to implement than the first, though neither is particularly trivial. But they are not tightly interdependent; each can be worked on separately at first and then integrated together at a later stage. Apart from the material in Chapters 8, 14 & 22 (especially Sections 22.5 - 22.7), and the experience you gained from the preceding assignment, you will also need to refer to the following : ioctl function (Chapter 17). get_ifi_info function (Section 17.6, Chapter 17). This function will be used by the server code to discover its node’s network interfaces so that it can bind all its interface IP addresses (see Section 22.6). ‘Race’ conditions (Section 20.5, Chapter 20) You also need a thorough understanding of how the TCP protocol implements reliable data transfer, flow control and congestion control. Chapters 17- 24 of TCP/IP Illustrated, Volume 1 by W. Richard Stevens gives a good overview of TCP. Though somewhat dated for some things (it was published in 1994), it remains, overall, a good basic reference. Overview This assignment asks you to implement a primitive file transfer protocol for Unix platforms, based on UDP, and with TCP-like reliability added to the transfer operation using timeouts and sliding-window mechanisms, and implementing flow and congestion control. The server is a concurrent server which can handle multiple clients simultaneously. A client gives the server the name of a file. The server forks off a child which reads directly from the file and transfers the contents over to the client using UDP datagrams. The client prints out the file contents as they come in, in order, with nothing missing and with no duplication of content, directly on to stdout (via the receiver sliding window, of course, but with no other intermediate buffering). The file to be transferred can be of arbitrary length, but its contents are always straightforward ascii text. As an aside let me mention that assuming the file contents ascii is not as restrictive as it sounds. We can always pretend, for example, that binary files are base64 encoded (“ASCII armor”). A real file transfer protocol would, of course, have to worry about transferring files between heterogeneous platforms with different file structure conventions and semantics. The sender would first have to transform the file into a platform-independent, protocol-defined, format (using, say, ASN.1, or some such standard), and the receiver would have to transform the received file into its platform’s native file format. This kind of thing can be fairly time consuming, and is certainly very tedious, to implement, with little educational value - it is not part of this assignment. Arguments for the server You should provide the server with an input file server.in from which it reads the following information, in the order shown, one item per line : Well-known port number for server. Maximum sending sliding-window size (in datagram units). You will not be handing in your server.in file. We shall create our own when we come to test your code. So it is important that you stick strictly to the file name and content conventions specified above. The same applies to the client.in input file below. Arguments for the client The client is to be provided with an input file client.in from which it reads the following information, in the order shown, one item per line : IP address of server (not the hostname). Well-known port number of server. filename to be transferred. Receiving sliding-window size (in datagram units). Random generator seed value. Probability p of datagram loss. This should be a real number in the range [ 0.0 , 1.0 ] (value 0.0 means no loss occurs; value 1.0 means all datagrams all lost). The mean µ, in milliseconds, for an exponential distribution controlling the rate at which the client reads received datagram payloads from its receive buffer. Operation Server starts up and reads its arguments from file server.in. As we shall see, when a client communicates with the server, the server will want to know what IP address that client is using to identify the server (i.e. , the destination IP address in the incoming datagram). Normally, this can be done relatively straightforwardly using the IP_RECVDESTADDR socket option, and picking up the information using the ancillary data (‘control information’) capability of the recvmsg function. Unfortunately, Solaris 2.10 does not support the IP_RECVDESTADDR option (nor, incidentally, does it support the msg_flags option in msghdr - see p.390). This considerably complicates things. In the absence of IP_RECVDESTADDR, what the server has to do as part of its initialization phase is to bind each IP address it has (and, simultaneously, its well-known port number, which it has read in from server.in) to a separate UDP socket. The code in Section 22.6, which uses the get_ifi_info function, shows you how to do that. However, there are important differences between that code and the version you want to implement. The code of Section 22.6 binds the IP addresses and forks off a child for each address that is bound to. We do not want to do that. Instead you should have an array of socket descriptors. For each IP address, create a new socket and bind the address (and well-known port number) to the socket without forking off child processes. Creating child processes comes later, when clients arrive. The code of Section 22.6 also attempts to bind broadcast addresses. We do not want to do this. It binds a wildcard IP address, which we certainly do not want to do either. We should bind strictly only unicast addresses (including the loopback address). The get_ifi_info function (which the code in Section 22.6 uses) has to be modified so that it also gets the network masks for the IP addresses of the node, and adds these to the information stored in the linked list of ifi_info structures (see Figure 17.5, p.471) it produces. As you go binding each IP address to a distinct socket, it will be useful for later processing to build your own array of structures, where a structure element records the following information for each socket : sockfd IP address bound to the socket network mask for the IP address subnet address (obtained by doing a bit-wise and between the IP address and its network mask) Report, in a ReadMe file which you hand in with your code, on the modifications you had to introduce to ensure that only unicast addresses are bound, and on your implementation of the array of structures described above. You should print out on stdout, with an appropriate message and appropriately formatted in dotted decimal notation, the IP address, network mask, and subnet address for each socket in your array of structures (you do not need to print the sockfd). The server now uses select to monitor the sockets it has created for incoming datagrams. When it returns from select, it must use recvfrom or recvmsg to read the incoming datagram (see 6. below). When a client starts, it first reads its arguments from the file client.in. The client checks if the server host is ‘local’ to its (extended) Ethernet. If so, all its communication to the server is to occur as MSG_DONTROUTE (or SO_DONTROUTE socket option). It determines if the server host is ‘local’ as follows. The first thing the client should do is to use the modified get_ifi_info function to obtain all of its IP addresses and associated network masks. Print out on stdout, in dotted decimal notation and with an appropriate message, the IP addresses and network masks obtained. In the following, IPserver designates the IP address the client will use to identify the server, and IPclient designates the IP address the client will choose to identify itself. The client checks whether the server is on the same host. If so, it should use the loopback address 127.0.0.1 for the server (i.e. , IPserver = 127.0.0.1). IPclient should also be set to the loopback address. Otherwise it proceeds as follows: IPserver is set to the IP address for the server in the client.in file. Given IPserver and the (unicast) IP addresses and network masks for the client returned by get_ifi_info in the linked list of ifi_info structures, you should be able to figure out if the server node is ‘local’ or not. This will be discussed in class; but let me just remind you here that you should use ‘longest prefix matching’ where applicable. If there are multiple client addresses, and the server host is ‘local’, the client chooses an IP address for itself, IPclient, which matches up as ‘local’ according to your examination above. If the server host is not ‘local’, then IPclient can be chosen arbitrarily. Print out on stdout the results of your examination, as to whether the server host is ‘local’ or not, as well as the IPclient and IPserver addresses selected. Note that this manner of determining whether the server is local or not is somewhat clumsy and ‘over-engineered’, and, as such, should be viewed more in the nature of a pedagogical exercise. Ideally, we would like to look up the server IP address(es) in the routing table (see Section 18.3). This requires that a routing socket be created, for which we need superuser privilege. Alternatively, we might want to dump out the routing table, using the sysctl function for example (see Section 18.4), and examine it directly. Unfortunately, Solaris 2.10 does not support sysctl. Furthermore, note that there is a slight problem with the address 130.245.1.123/24 assigned to compserv3 (see rightmost column of file hosts, and note that this particular compserv3 address “overlaps” with the 130.245.1.x/28 addresses in that same column assigned to compserv1, compserv2 & comserv4). In particular, if the client is running on compserv3 and the server on any of the other three compservs, and if that server node is also being identified to the client by its /28 (rather than its /24) address, then the client will get a “false positive” when it tests as to whether the server node is local or not. In other words, the client will deem the server node to be local, whereas in fact it should not be considered local. Because of this, it is perhaps best simply not to use compserv3 to run the client (but it is o.k. to use it to run the server). Finally, using MSG_DONTROUTE where possible would seem to gain us efficiency, in as much as the kernel does not need to consult the routing table for every datagram sent. But, in fact, that is not so. Recall that one effect of connect with UDP sockets is that routing information is obtained by the kernel at the time the connect is issued. That information is cached and used for subsequent sends from the connected socket (see p.255). The client now creates a UDP socket and calls bind on IPclient, with 0 as the port number. This will cause the kernel to bind an ephemeral port to the socket. After the bind, use the getsockname function (Section 4.10) to obtain IPclient and the ephemeral port number that has been assigned to the socket, and print that information out on stdout, with an appropriate message and appropriately formatted. The client connects its socket to IPserver and the well-known port number of the server. After the connect, use the getpeername function (Section 4.10) to obtain IPserver and the well-known port number of the server, and print that information out on stdout, with an appropriate message and appropriately formatted. The client sends a datagram to the server giving the filename for the transfer. This send needs to be backed up by a timeout in case the datagram is lost. Note that the incoming datagram from the client will be delivered to the server at the socket to which the destination IP address that the datagram is carrying has been bound. Thus, the server can obtain that address (it is, of course, IPserver) and thereby achieve what IP_RECVDESTADDR would have given us had it been available. Furthermore, the server process can obtain the IP address (this will, of course, be IPclient) and ephemeral port number of the client through the recvfrom or recvmsg functions. The server forks off a child process to handle the client. The server parent process goes back to the select to listen for new clients. Hereafter, and unless otherwise stated, whenever we refer to the ‘server’, we mean the server child process handling the client’s file transfer, not the server parent process. Typically, the first thing the server child would be expected to do is to close all sockets it ‘inherits’ from its parent. However, this is not the case with us. The server child does indeed close the sockets it inherited, but not the socket on which the client request arrived. It leaves that socket open for now. Call this socket the ‘listening’ socket. The server (child) then checks if the client host is local to its (extended) Ethernet. If so, all its communication to the client is to occur as MSG_DONTROUTE (or SO_DONTROUTE socket option). If IPserver (obtained in 5. above) is the loopback address, then we are done. Otherwise, the server has to proceed with the following step. Use the array of structures you built in 1. above, together with the addresses IPserver and IPclient to determine if the client is ‘local’. Print out on stdout the results of your examination, as to whether the client host is ‘local’ or not. The server (child) creates a UDP socket to handle file transfer to the client. Call this socket the ‘connection’ socket. It binds the socket to IPserver, with port number 0 so that its kernel assigns an ephemeral port. After the bind, use the getsockname function (Section 4.10) to obtain IPserver and the ephemeral port number that has been assigned to the socket, and print that information out on stdout, with an appropriate message and appropriately formatted. The server then connects this ‘connection’ socket to the client’s IPclient and ephemeral port number. The server now sends the client a datagram, in which it passes it the ephemeral port number of its ‘connection’ socket as the data payload of the datagram. This datagram is sent using the ‘listening’ socket inherited from its parent, otherwise the client (whose socket is connected to the server’s ‘listening’ socket at the latter’s well-known port number) will reject it. This datagram must be backed up by the ARQ mechanism, and retransmitted in the event of loss. Note that if this datagram is indeed lost, the client might well time out and retransmit its original request message (the one carrying the file name). In this event, you must somehow ensure that the parent server does not mistake this retransmitted request for a new client coming in, and spawn off yet another child to handle it. How do you do that? It is potentially more involved than it might seem. I will be discussing this in class, as well as ‘race’ conditions that could potentially arise, depending on how you code the mechanisms I present. When the client receives the datagram carrying the ephemeral port number of the server’s ‘connection’ socket, it reconnects its socket to the server’s ‘connection’ socket, using IPserver and the ephemeral port number received in the datagram (see p.254). It now uses this reconnected socket to send the server an acknowledgment. Note that this implies that, in the event of the server timing out, it should retransmit two copies of its ‘ephemeral port number’ message, one on its ‘listening’ socket and the other on its ‘connection’ socket (why?). When the server receives the acknowledgment, it closes the ‘listening’ socket it inherited from its parent. The server can now commence the file transfer through its ‘connection’ socket. The net effect of all these binds and connects at server and client is that no ‘outsider’ UDP datagram (broadcast, multicast, unicast - fortuitously or maliciously) can now intrude on the communication between server and client. Starting with the first datagram sent out, the client behaves as follows. Whenever a datagram arrives, or an ACK is about to be sent out (or, indeed, the initial datagram to the server giving the filename for the transfer), the client uses some random number generator function random() (initialized by the client.in argument value seed) to decide with probability p (another client.in argument value) if the datagram or ACK should be discarded by way of simulating transmission loss across the network. (I will briefly discuss in class how you do this.) Adding reliability to UDP The mechanisms you are to implement are based on TCP Reno. These include : Reliable data transmission using ARQ sliding-windows, with Fast Retransmit. Flow control via receiver window advertisements. Congestion control that implements : SlowStart Congestion Avoidance (‘Additive-Increase/Multiplicative Decrease’ – AIMD) Fast Recovery (but without the window-inflation aspect of Fast Recovery) Only some, and by no means all, of the details for these are covered below. The rest will be presented in class, especially those concerning flow control and TCP Reno’s congestion control mechanisms in general : Slow Start, Congestion Avoidance, Fast Retransmit and Fast Recovery. Implement a timeout mechanism on the sender (server) side. This is available to you from Stevens, Section 22.5 . Note, however, that you will need to modify the basic driving mechanism of Figure 22.7 appropriately since the situation at the sender side is not a repetitive cycle of send-receive, but rather a straightforward progression of send-send-send-send- . . . . . . . . . . . Also, modify the RTT and RTO mechanisms of Section 22.5 as specified below. I will be discussing the details of these modifications and the reasons for them in class. Modify function rtt_stop (Fig. 22.13) so that it uses integer arithmetic rather than floating point. This will entail your also having to modify some of the variable and function parameter declarations throughout Section 22.5 from float to int, as appropriate. In the unprrt.h header file (Fig. 22.10) set : RTT_RXTMIN to 1000 msec. (1 sec. instead of the current value 3 sec.) RTT_RXTMAX to 3000 msec. (3 sec. instead of the current value 60 sec.) RTT_MAXNREXMT to 12 (instead of the current value 3) In function rtt_timeout (Fig. 22.14), after doubling the RTO in line 86, pass its value through the function rtt_minmax of Fig. 22.11 (somewhat along the lines of what is done in line 77 of rtt_stop, Fig. 22.13). Finally, note that with the modification to integer calculation of the smoothed RTT and its variation, and given the small RTT values you will experience on the cs / sbpub network, these calculations should probably now be done on a millisecond or even microsecond scale (rather than in seconds, as is the case with Stevens’ code). Otherwise, small measured RTTs could show up as 0 on a scale of seconds, yielding a negative result when we subtract the smoothed RTT from the measured RTT (line 72 of rtt_stop, Fig. 22.13). Report the details of your modifications to the code of Section 22.5 in the ReadMe file which you hand in with your code. We need to have a sender sliding window mechanism for the retransmission of lost datagrams; and a receiver sliding window in order to ensure correct sequencing of received file contents, and some measure of flow control. You should implement something based on TCP Reno’s mechanisms, with cumulative acknowledgments, receiver window advertisements, and a congestion control mechanism I will explain in detail in class. For a reference on TCP’s mechanisms generally, see W. Richard Stevens, TCP/IP Illustrated, Volume 1 , especially Sections 20.2 - 20.4 of Chapter 20 , and Sections 21.1 - 21.8 of Chapter 21 . Bear in mind that our sequence numbers should count datagrams, not bytes as in TCP. Remember that the sender and receiver window sizes have to be set according to the argument values in client.in and server.in, respectively. Whenever the sender window becomes full and so ‘locks’, the server should print out a message to that effect on stdout. Similarly, whenever the receiver window ‘locks’, the client should print out a message on stdout. Be aware of the potential for deadlock when the receiver window ‘locks’. This situation is handled by having the receiver process send a duplicate ACK which acts as a window update when its window opens again (see Figure 20.3 and the discussion about it in TCP/IP Illustrated). However, this is not enough, because ACKs are not backed up by a timeout mechanism in the event they are lost. So we will also need to implement a persist timer driving window probes in the sender process (see Sections 22.1 & 22.2 in Chapter 22 of TCP/IP Illustrated). Note that you do not have to worry about the Silly Window Syndrome discussed in Section 22.3 of TCP/IP Illustrated since the receiver process consumes ‘full sized’ 512-byte messages from the receiver buffer (see 3. below). Report on the details of the ARQ mechanism you implemented in the ReadMe file you hand in. Indeed, you should report on all the TCP mechanisms you implemented in the ReadMe file, both the ones discussed here, and the ones I will be discussing in class. Make your datagram payload a fixed 512 bytes, inclusive of the file transfer protocol header (which must, at the very least, carry: the sequence number of the datagram; ACKs; and advertised window notifications). The client reads the file contents in its receive buffer and prints them out on stdout using a separate thread. This thread sits in a repetitive loop till all the file contents have been printed out, doing the following. It samples from an exponential distribution with mean µ milliseconds (read from the client.in file), sleeps for that number of milliseconds; wakes up to read and print all in-order file contents available in the receive buffer at that point; samples again from the exponential distribution; sleeps; and so on. The formula -1 × µ × ln( random( ) ) , where ln is the natural logarithm, yields variates from an exponential distribution with mean µ, based on the uniformly-distributed variates over ( 0 , 1 ) returned by random(). Note that you will need to implement some sort of mutual exclusion/semaphore mechanism on the client side so that the thread that sleeps and wakes up to consume from the receive buffer is not updating the state variables of the buffer at the same time as the main thread reading from the socket and depositing into the buffer is doing the same. Furthermore, we need to ensure that the main thread does not effectively monopolize the semaphore (and thus lock out for prolonged periods of time) the sleeping thread when the latter wakes up. See the textbook, Section 26.7, ‘Mutexes: Mutual Exclusion’, pp.697-701. You might also find Section 26.8, ‘Condition Variables’, pp.701-705, useful. You will need to devise some way by which the sender can notify the receiver when it has sent the last datagram of the file transfer, without the receiver mistaking that EOF marker as part of the file contents. (Also, note that the last data segment could be a “short” segment of less than 512 bytes – your client needs to be able to handle this correctly somehow.) When the sender receives an ACK for the last datagram of the transfer, the (child) server terminates. The parent server has to take care of cleaning up zombie children. Note that if we want a clean closing, the client process cannot simply terminate when the receiver ACKs the last datagram. This ACK could be lost, which would leave the (child) server process ‘hanging’, timing out, and retransmitting the last datagram. TCP attempts to deal with this problem by means of the TIME_WAIT state. You should have your receiver process behave similarly, sticking around in something akin to a TIME_WAIT state in case in case it needs to retransmit the ACK. In the ReadMe file you hand in, report on how you dealt with the issues raised here: sender notifying receiver of the last datagram, clean closing, and so on. Output Some of the output required from your program has been described in the section Operation above. I expect you to provide further output – clear, well-structured, well-laid-out, concise but sufficient and helpful – in the client and server windows by means of which we can trace the correct evolution of your TCP’s behaviour in all its intricacies : information (e.g., sequence number) on datagrams and acks sent and dropped, window advertisements, datagram retransmissions (and why : dup acks or RTO); entering/exiting Slow Start and Congestion Avoidance, ssthresh and cwnd values; sender and receiver windows locking/unlocking; etc., etc. . . . . The onus is on you to convince us that the TCP mechanisms you implemented are working correctly. Too many students do not put sufficient thought, creative imagination, time or effort into this. It is not the TA’s nor my responsibility to sit staring at an essentially blank screen, trying to summon up our paranormal psychology skills to figure out if your TCP implementation is really working correctly in all its very intricate aspects, simply because the transferred file seems to be printing o.k. in the client window. Nor is it our responsibility to strain our eyes and our patience wading through a mountain of obscure, ill-structured, hyper-messy, debugging-style output because, for example, your effort-conserving concept of what is ‘suitable’ is to dump your debugging output on us, relevant, irrelevant, and everything in between.
lukas-reining / EventsourceEventSource implementation that is fully compliant with the WHATWG Server-Sent Events specification but takes more arguments.
vgno / SsehubServer Sent Events Hub
kEND / MCP SseAn elixir Model Context Protocal (MCP) server library which uses the Server-Sent Events (SSE) transport type
segment-boneyard / Sse StreamA Server-Sent Events transform stream
roniemartinez / Real Time Charts With FastapiSample application for the blog "Creating Real-Time Charts with FastAPI"
saasscaleup / Laravel Console LogPHP version of console log for Laravel. Easily stream your Laravel application logs to the browser console tab (console.log) in real-time using server-sent event (SSE)
JohT / Showcase Quarkus EventsourcingShows an example on how to use AxonFramework in conjunction with microprofile on quarkus
