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diff --git a/doc/rfc/rfc121.txt b/doc/rfc/rfc121.txt new file mode 100644 index 0000000..af0c1f1 --- /dev/null +++ b/doc/rfc/rfc121.txt @@ -0,0 +1,731 @@ + + + + + + +Network Working Group M. Krilanovich +Request for Comments: 121 Computer Research Lab, UCSB +NIC: 5833 21 April 1971 + + + NETWORK ON-LINE OPERATORS + +PREFACE + + The operators described in this document have been implemented within + UCSB's On-Line System and make the Network (via the NCP) accessible + to On-Line System users. + + A set of operators is provided to facilitate the use of the Network + by On-Line System users. The operators are defined on LVL I on + system 'NET', and serve an an interface between the users and the + Network Control Program (NCP), which supervises all Network + operations at this site. + + A concept fundamental to On-Line System Network operations is that of + a completion code variable. Associated with each socket that is not + in the closed state is a unique variable, called a completion code + variable. This variable serves two purpose: it identifies the local + socket referenced, and upon completion of the operation it contains a + completion code to indicate the outcome of the operation to the user. + It may be used at any time for any purpose other than Network + operations. Its value at the beginning of a Network operation is + immaterial rather it is the variable itself that is important. In + all Network operations, whenever a completion code variable is called + for, the only acceptable type variable is a LO storage location, + either case 1 or case 2. + + In those operations requiring a socket to be specified by its socket + identifier, the following format is used: the site number of UCSB is + always used for local sockets, and so this item is never specified. + The site number of a foreign socket, if specified, must be a positive + integer or a LO storage location, and must be less then 256 in value. + If not specified, the site number of a foreign socket will default to + the site number of UCSB. A socket number is specified as an integer, + either unsigned, in which case it is assumed to be positive, or with + an explicit minus sign, or a LO storage location, of any value. + Negative socket numbers are represented internally in two's + complement form and therefore for the purpose of the gender of a + socket, a socket number is even or odd according to whether its + absolute value is even or odd, respectively. + + + + + + +Krilanovich [Page 1] + +RFC 121 Network On-Line Operators April 1971 + + + In all operations involving the On-Line System Network operators, + there are certain conventions concerning the format of the data sent + and received. The data is grouped in 'messages' consisting of three + fields, op code, length, an text, in that order. The op code is one + byte in length and is a code which indicates how the text field is to + be interpreted. The length field is two bytes long, and gives the + length, in bits, of the text field, which contains the actual data. + (The op code and length fields together are termed a header.) + + The following op codes are presently defined: + + op code meaning + + 0 This op code is a NOP. No text field exists, and the + contents of the length field are unpredictable. (This + op code is used mainly as a delimiter.) + + 1 The text field contains EBCDIC characters, one + character per byte. The On-Line System operators + consider the characters as intended for display as + soon as the text field has been received. + + 2 The text contains codes for keypushes, one byte per + key. The On-Line operators consider the keys as + intended for execution as soon as the text field has + been received. + + 3 The same as for an op code of 2, except that the On- + Line operators consider that the execution of the keys + will be delayed until all data for that receive + operation has been received. + + The standard format of data sent or received by the On-Line System + operators is a string of messages, with the last message indicated by + a header with a NOP op code, called a trailer. These conventions are + the default situation; any of them may be overridden by appropriate + programming. Following is a description of each operator, its + function and key sequence. + + (1) OPEN + + By invoking this operator, the user requests that the specified + local socket be removed from the closed state and thus be prepared + to participate in data transfer. There are three distinct + operations that can be performed by this operator and these are + described below: + + + + + +Krilanovich [Page 2] + +RFC 121 Network On-Line Operators April 1971 + + + (A) CONNECT + + By invoking this operator, the user requests that the specified + local socket be logically connected to the specified foreign + socket, and that transfer of data be enabled between the two + sockets. Processing at the terminal is suspended until the + foreign sockets either accepts or rejects the connection + attempt. This operation is valid only when the local socket is + in the closed state. + + The key sequence is as follows: + + UP Q1 Q2,Q3[,Q4] RETURN + + where + + Q1 is the completion code variable to be associated with the + local socket. + Q2 is the socket number of the local socket. + Q3 is the socket number of the foreign socket. + Q4 is the site number of the foreign socket. + + The following completion codes are possible for this operation: + + 0, The operation was successful and the connection has been + established + 4, The specified completion code variable is already + assigned to a socket; the operation was suppressed + 8, The specified local socket is not in the closed state; + the operation was suppressed + 12, All communication paths to the specified foreign site + are in use; the operator was suppressed + 16, Local resources are insufficient to support another + connection; the operation was suppressed + 20, The connection attempt was rejected by the foreign + process + 28, The specified foreign site is invalid; the operation was + suppressed + 36, Either hardware at the foreign site is inoperative or + the NCP's counter-part at the foreign site does not exist + or has failed + 40, Local and foreign sockets are both either send or + receive sockets; the operation was suppressed + 44, By operator command, all Network operations were + terminated; the socket will be closed + 60, An NCP control transmission error occurred; the + operation as suppressed + + + + +Krilanovich [Page 3] + +RFC 121 Network On-Line Operators April 1971 + + + (B) LISTEN + + This operation is a request for notification of any connection + attempt directed toward the specified local socket. Processing + at the terminal is suspended until such a call is received. + This operation is valid only when the designated local socket + is in the closed state. + + The key sequence is as follows: + + UP Q1 Q2 RETURN + + where + + Q1 is the completion code variable to be associated with the + local socket. + Q2 is the socket number of the local socket. + + The following completion codes are possible for this + operation: + + 0, The operation was successful and a call has been received + 4, The specified completion code variable is already + assigned to a socket; the operation was suppressed + 8, The specified local socket is not in the closed state; + the operation was suppressed + 12, Local resource are insufficient to support another + connection; the operation was suppressed + 44, By operator command, all Network operations were + terminated; the socket will be closed + + (C) ACCEPT + + This operation accepts connection with the foreign socket whose + call caused successful completion of a previous LISTEN + operation by the specified local socket. After completion of + this operation, data may be transferred to or from the local + socket, depending on its gender. This operation is valid only + when the last operation referencing the local socket as a + LISTEN operation. Processing at the terminal is suspended + until the operation is completed. + + The key sequence is as follows: + + UP Q RETURN + + + + + + +Krilanovich [Page 4] + +RFC 121 Network On-Line Operators April 1971 + + + where + + Q is the completion code variable associated with the local + socket by a previous LISTEN operation. + + The following completion codes are possible for this + operation: + + 0, The operation as successful, and the connection is + established + 4, The specified local socket is in the closed state + (the NCP may have received an abort notification + from the foreign process); the operation was + suppressed + 8, The previous operation specifying the designated + local socket was not a LISTEN; the operation was + suppressed + 12, All communication paths to the specified foreign + site are in use; the socket has been returned to + the closed state + + + (2) CLOSE + + This operation is a request that the specified local socket be + returned to the closed state. If the last operation involving + this socket was a LISTEN, this operation refuses the foreign + process connection attempt. If the last operation was a CONNECT, + the attempt is aborted. If a connection is established, any data + in transit form the local socket is allowed to reach the foreign + socket and to be either received or flushed before the local + socket is closed. + + Processing at the terminal is suspended until the socket has been + returned to the closed state. + + The key sequence is as follows: + + DWN Q + + + + + + + + + + + + +Krilanovich [Page 5] + +RFC 121 Network On-Line Operators April 1971 + + + where + + Q is the completion code variable associated with the local + socket. + + The following completion codes are possible for this + operation: + + 0, The operation was successful, and the socket has + been returned to the closed state + 8, The specified completion code variable is not + currently assigned to a socket; the operation was + suppressed + 12, The specified local socket is in the process of + being closed the operation was suppressed, but the + local socket will be closed + 36, Either hardware at the foreign site is + inoperative, or the NCP's counterpart at the + foreign site does not exist or has failed + 44, By operator command, all Network operations were + terminated; the socket will be closed + 60, An NCP control transmission error occurred; the + operation was aborted + 64, A transmission error occurred the operation was + aborted, but the socket will be closed + + (3) SEND + + This operation caused data to be sent to the foreign socket. + Processing at the terminal is suspended until the data has been + received by the foreign socket, or until it has been queued + locally by the NCP. + + The possible key sequence are as follows: + + STORE Q1 Q2 text Q2 + STORE +Q1 Q2 text Q2 + STORE -Q1 Q2 text Q2 + STORE .Q1[X]Q3 RETURN + + where + + Q1 is the completion code variable associated with the local + socket. + Q2 is any key except RESET. + 'Text' is a string of any length of any keys except Q2 and + RESET. + Q3 is an unsigned integer. If it is preceded by 'X', the + + + +Krilanovich [Page 6] + +RFC 121 Network On-Line Operators April 1971 + + + integer is assumed to be in hexadecimal. + [X]Q3 should have a value less then 256. + + If Q1 is the first key after STORE, the keys comprising 'text' are + not executed but rather are sent as a one byte code per key, in + one or more standard messages. They are preceded by a header with + the op code which indicates keys to be executed as soon as they + are received, and followed by a trailer. If a '+' precedes Q1, + the headers and the text will be sent, but no trailer. If a '-' + precedes Q1, only the text will be sent. If a '.' precedes Q1, + [X]Q3 will be sent as a one byte number, with no header or + trailer. + + The following completion codes are possible for this operation: + + 0, The operation was successful, and the data has been sent + 4, The specified local socket is not a send socket; the + operation was suppressed + 8, The specified completion code variable is not assigned to + a socket; the operation was suppressed + 12, A previous send operation is in progress ;the operation + was suppressed + 16, The connection is not fully open; the operation was + suppressed + 20, The foreign socket terminated the connection before + completion of the send operation; not all the data was + transmitted + 36, Either hardware at the foreign site is inoperative, or + the NCP's counterpart at the foreign site does not exist + or has failed + 44, By operator command, all Network operations were + terminated the socket will be closed + 52, One or more interrupts were received from the foreign + socket; the operation was suppressed + 60, An NCP control transmission error occurred; the + operation was aborted and the socket will be closed + 64, A transmission error occurred; the operation was aborted + and the socket will be closed + + (4) RECEIVE + + This operation causes data to be received from the foreign socket. + Processing at the terminal is suspended until the data sent by the + foreign socket has been received by the local socket and + processed. + + The possible key sequences are as follows: + + + + +Krilanovich [Page 7] + +RFC 121 Network On-Line Operators April 1971 + + + LOAD Q1 + LOAD +Q1 + LOAD -Q1 Q2, Q3 RETURN + LOAD .Q1 Q4 RETURN + + where + + Q1 is the completion code variable associated with the local + socket. + Q2 is a positive integer, or a LO storage location, less + then 256. + Q3 is a positive integer, or a LO storage location, less + than 65536 + Q4 is a positive integer less than 5. + + If Q1 is the first key after LOAD, one or more standard messages + will be received and executed. The data may or may not be + executed, as soon as it is received, depending on the op code. + Processing of manual keypushes is suspended until a trailer is + received. If Q1 is preceded by a '+', the operation is as above, + except that only one message, with no trailer, is received, and + the operation is only performed if there is data queued for the + local socket, ready to be received. ('LOAD +' is intended mainly + for use with the Network On-Line Interface.) If Q1 is preceded by + a '-', a string of text whose length, in bits, is Q3, is received + and processed according to the op code Q2. If a '.' precedes Q1, + Q4 bytes of data are read and placed, right justified, in the LO + accumulator. + + The following completion codes are possible for this operation: + + 0, The operation was successful and the data has been + received + 4, The specified local socket is not a receive socket; the + operation was suppressed + 8, The specified completion code variable is not assigned to + a socket; the operation was suppressed + 12, A previous receive operation is in progres; the + operation was suppressed + 16, The connection is not fully open; the operation was + suppressed + 20, The foreign socket terminated the connection before + completion of the receive operation; data is + unpredictable + 36, Either hardware at the foreign site is inoperative, or + the NCP's counterpart at the foreign site does not exist + or has failed + 44, By operator command, all Network operations were + + + +Krilanovich [Page 8] + +RFC 121 Network On-Line Operators April 1971 + + + terminated; the socket will be closed + 52, One or more interrupts were received from the foreign + socket; the operation was suppressed + 60, An NCP control transmission error occurred; the + operation was suppressed and the socket will be closed + 200, There was no data queued for the local socket; the + operation was suppressed (applicable only to 'LOAD +') + + (5) CHECK + + This operation causes the status of the specified local socket to + be displayed. There is no completion code variable associated + with this operation, since it is always successful and the socket + is identified by its socket number. This operation is valid at + any time, and with one exception, noted below, is always completed + immediately. + + The possible key sequences are as follows: + + DISPLAY (Q RETURN...)... + DISPLAY (Q?)... + DISPLAY RETURN... + + where + + Q is the socket number of the local socket whose status is + to be displayed. + + Successive RETURN'S will display the status of local sockets with + successively higher socket numbers, and once DISPLAY has been + pushed, it need not be pushed for subsequent occurrences of Q. + + If Q is followed by a '?', processing at the terminal will be + suspended until the socket is not in the closed state, at which + time the status will be displayed. If the socket is not closed at + the time the '?' is pushed, response is as if the '?' were a + RETURN. + + If DISPLAY is followed immediately by a RETURN, the status of all + non-closed sockets owned by the terminal is displayed, each + preceded by its associated completion code variable. If this + information is more than will fit on one tube, successive RETURN'S + will display the remainder of the information. + + + + + + + + +Krilanovich [Page 9] + +RFC 121 Network On-Line Operators April 1971 + + + The status has the following format: + + 'lclno' 'mnem' 'fgnsite' 'fgnno' 'deficit' + + where + + 'lclno' is the socket number of the local socket. + 'mnem' is a mnemonic of up to eight characters for the + status. + 'fgnsite' is the site number of the foreign socket, or + blank. + 'fgnno' is the socket number of the foreign socket, or + blank. + 'deficit' is the send/receive deficit in the form + 'bytes.bits', or blank. + + Following are the possible mnemonics, together with their + interpretations: + + 'MNEM' MEANING + ______ _______ + + OPEN A connection is fully established. + No SEND/RECEIVE operation is in progress. + 'fgnsite' and 'fgnno' are the site number and + the socket number of the connected socket. + 'deficit' is the number of bits queued locally + at the socket by the NCP and available to + satisfy a future RECEIVE operation, or awaiting + output as the result of a previous SEND + operation. + + LISTEN A LISTEN has been issued. + + CONNECT A CONNECT has been issued. 'fngsite' and 'fgnno' + are the site and socket numbers of the foreign + socket. + + DECISION A LISTEN has been completed. 'fgnsite' and + 'fgnno' are the site and socket numbers of the + calling socket. + + CALL(S) One or more calls have been received for the + local socket. No LISTEN or CONNECT has been + issued. + + I/O A connection is fully established. A + SEND/RECEIVE operation is in progress. 'fgnsite' + + + +Krilanovich [Page 10] + +RFC 121 Network On-Line Operators April 1971 + + + and 'fgnno' are the site and socket numbers of + the connected socket. 'deficit' is the number of + bits yet to be sent or received. + + CLOSED The socket is in the closed state. + + <--DRAIN The foreign socket is attempting to close the + connection. The NCP has data yet to be read by + the local socket. 'fgnsite' and 'fgnno' are the + site and socket numbers of the connected socket. + 'deficit' is the number of bits yet to be + received. + + DRAINED The foreign socket is attempting to close the + connection. The NCP is awaiting arrival at the + foreign site of data currently in transit. + 'fgnsite' and 'fgnno' are the site and socket + numbers of the connected socket. + + CLOSING The local socket has issued a CLOSE. The NCP is + in the process of returning the local socket to + the closed state. 'fgnsite' and 'fgnno' are the + site and socket numbers of the connected socket. + + DRAIN--> The local socket has issued a CLOSE. The NCP is + completing the last SEND operation before + returning the local socket to the closed state. + 'fgnsite' and 'fgnno' are the site and socket + numbers of the connected socket. 'deficit' is + the number of bits the NCP has yet to transmit. + + (6) IDENTIFY + + This operation is used to identify a local socket by its + completion code variable. The operation is valid at any time, and + is always completed immediately. Since it is always successful, + there are no completion codes for the operation, and the contents + of the completion code variable are not changed. + + The key sequence is: + + ID Q... + + where + + Q is the completion code variable associated with the local + socket. + + + + +Krilanovich [Page 11] + +RFC 121 Network On-Line Operators April 1971 + + + The response is a display of Q, followed by 'IS UNDEFINED' if the + socket is in the closed state, or the socket number associated + with it if it is not closed. After ID has been pushed once, it + need not be pushed again for subsequent occurrences of Q. + + (7) PURGE + + This operator is used to dissociate all completion code variables + from sockets, and to issue a CLOSE to all sockets currently in use + at the terminal. The operation is valid at any time, and is + always completed immediately. Since it is always successful. + there are no completion codes for the operation, and the contents + of the completion code variables are not changed. + + The key sequence is: + + DEL RETURN + + (8) SIGNAL + + This operation is used to convey a signal to the foreign process. + The significance of the signal is completely user-dependent. The + effect is that the next time the foreign socket attempts to + initiate a RECEIVE or SEND operation, the operation will be + suppressed, and a completion code supplied indicating that a + signal had been received. Processing at the terminal is suspended + until the signal has been sent to the foreign NCP. This operation + is valid only when the socket is fully open. + + The key sequence is: + + REFL Q + + where + + Q is the completion code variable associated with the local + socket. + + The following completion codes are possible for this operation: + + 0, The operation was successful, and the signal has been + sent + 4, The specified completion code variable is not assigned to + a socket; the operation was suppressed + 8, The connection is not fully open;the operation was + suppressed + + + + + +Krilanovich [Page 12] + +RFC 121 Network On-Line Operators April 1971 + + + (9) CONVERSATIONAL CONTROLLER + + This operator is intended primarily for use with the Network On- + Line Interface, and is used to carry on a 'conversation' with the + foreign process. Any data queued locally for the specified local + receive socket is received and displayed as characters. Any keys + pushed will be sent from the specified local send socket. The + user has the option of specifying whether or not upper keyboard + buttons are to be sent. In any case, the buttons ERASE, REPEAT, + ENTER, PRED, and RESET, will not be sent, and pushing any of + these, except RESET, will cause suspension of data reception until + a button other than these four is pushed. Pushing RESET always + terminates the operation. + + The key sequence is as follows: + + ARG [,] [-]Q1[-]Q2 + + where + + Q1 is the completion code variable associated with the local + send socket. + Q2 is the completion code variable associated with the local + receive socket. + + If ARG is followed by ',', both upper and lower keyboard buttons + will be sent, and the operation will be terminated only by pushing + RESET. If no ',' follows ARG, only lower keyboard buttons will be + sent, and the operation is terminated by pushing RESET or any + upper keyboard button. If a '-' precedes Q1, no headers will be + sent, and if a '-' precedes Q2, no headers will be received. In + any case, if headers are to be received, the operation is + terminated when a trailer is received, and a corresponding trailer + is sent if headers are to be sent. + + The completion codes for the send socket are the same as for the + SEND operation, and the completion codes for the receive socket + are the same as for the RECEIVE operation. If a non-zero + completion code is found, a message is displayed, either 'OUTPUT + ERROR' or 'INPUT ERROR', depending on whether the send socket for + the receive socket encountered the non-zero completion code, and + the operation is terminated. + + + [ This RFC was put into machine readable form for entry ] + [ into the online RFC archives by Gruss Gottfried 01/98 ] + + + + + +Krilanovich [Page 13] + |