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Versions: 00 01                                                         
Internet-Draft        Expires: June 1997         Internet-Draft

Category: Informational                          S. Ryckman
                                                 SIMS, Inc.


   Security Industry Internet Protocol for Alarm Transmission (SIIPAT)
                 <draft-rfced-info-ryckman-01.txt>

Status of this Memo

   This memo provides information for the Internet community.  This memo
   does not specify an Internet standard of any kind.  Distribution of
   this memo is unlimited.

   This document is an Internet-Draft.  Internet-Drafts are working
   documents of the Internet Engineering task Force (IETF), its areas,
   and its working groups.  Note that other groups may also distribute
   working documents as Internet-Drafts.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
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   To learn the current status of any Internet-Draft, please check the
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   ftp.isi.edu (US West Coast).

Abstract

   This document suggests a method for delivering alarm information over
   the Internet.  All communication shall use an encryption algorithm
   for transmission of the data.  An immediate response from the host
   will be used for verification of receipt of the message.

   This transmission method may be use as a backup transmission method
   to traditional dial-up or leased line methods, or as a primary
   transmission method with traditional methods becomming the backup.

   Due to the required security of the data being transmitted, the
   encryption algorithm used will only be released on a need to know
   basis to software developers in the Alarm/Security Industry.
   A non-disclosure agreement will be required.  Terms and conditions
   of the licensing will depend on the intended purpose for use and
   may require a non-competition agreement or licensing fees.

   The Internet Assigned Numbers Authority (IANA) has assigned port
   1733 for the registered use of SIIPAT transmissions.


1. Introduction

   This transmission protocol was developed to eliminate the need
   for dial-up communications to send short data bursts of alarm
   information.  Many times, the amount of time it takes to seize
   the dial-up phone line, dial the number and wait for an answer
   by the alarm receiving equipment is much greater than the amount
   of time it takes to transmit the data itself (even at 300 baud).
   Since many corporations and government agencies as well as alarm
   companies already have dedicated Internet connections, it seems
   resonable that it could be used as a quick transmission method.
   Due to the inherent probability of failures of the network at
   some point between origination and reception of the alarm signal,
   it should NOT be used for the sole transmission path for any
   signal.  This transmission method can be treated with the same
   concerns as a typical radio alarm transmission, quick but not
   entirely absolute.

   Throughout the remainder of this document the following terms
   will be used.

   Port/Socket - Used interchangably to refer to the logical
   connection created when the client software polls the host
   on a particular port number, in this case port 1733.

   SIIPAT - Security Industry Internet Protocol for Alarm
   Transmission (Pronounced Si-Pay).

   Server - The software running at the Alarm Company which is
   connected to the Internet and monitoring an IP address port.

   Subscriber - The software/device at the protected location.



2. System Philosophy

   Proposing an alternative method of transportation of alarm signals
   is not as easy to implement as it sounds.  A very simple adoption
   of such a feat could be accomplished with normal Email.  This would
   not provide immediate notification of receipt however, and would
   open the system up to tampering from external sources.  Clearly a
   secured encryption routine must be used, to prevent people from
   creating false signals or using the protocol for sending non-alarm
   information, as is possible with existing transmission formats.
   The principle of SIIPAT is to provide security to the alarm transmission
   process not found currently.  This is security both for the originator
   of the alarm signal (increased transmission speed) and for the
   alarm company (reduction of false signals due to tampering).
   Until every home has it's own direct connection to the Internet,
   SIIPAT can not be used for every alarm system.  It's primary purpose
   is for commercial applications or where the alarm signal may
   originate from a non-customary device such as a program on a
   computer used for monitoring network or environmental conditions,
   home automation/access control computerized systems or from
   radio network providers for vehicle location/tracking purposes.

   SIIPAT itself does not include definition for the equipment on either
   end of the transmission, only the format of the data in between.
   Implementation of SIIPAT may include a dedicated machine to
   act as the server or use of an automation software package which
   supports the SIIPAT interface directly.  The way the protocol is
   designed supports simple "generic" transmissions as well as
   emulating specific receiver signals so that an automation package
   can pass the message to an existing receiver interface.


3. Why use the Internet to send alarm messages ?

   Every day, more and more alarm companies are changing from small
   "mom and pop" companies, to nationwide or global monitoring stations.
   With the ever increasing competition from other companies, an alarm
   company must remain unique to remain in business.  Switching from
   a local geopgraphical area of coverage to a larger scale brings
   with it increased advantages, but also increased problems.  Using
   customary techniques requires either the use of "800" numbers at
   the alarm company (at great expense to the company) or long distance
   calls from the subscriber (where they eat the cost of the phone call).
   As contracts between large corporations and a single alarm company
   continue, the ability of one central location to monitor a chain
   of stores around the world becomes more and more expensive.  Sending
   open and close activity reports from a panel around the world could
   easily add up to the hundreds or thousands of dollars a month in
   customary phone long distance charages.  Because of this expense
   most sites do not implement test supervision signals unless maybe
   they are only once a day.  With SIIPAT supervision is a two-way
   street with the alarm company able to "inquiry" the status of a
   particular system at any moment, even every couple seconds if
   high-security warrants it.


4. The SIIPAT Protocol

   The SIIPAT protocol is a sequence of commands and replies, and is based
   loosely on the design of many other Internet protocols currently
   in use.  Please note that the protocol as described does not take
   into consideration the encryption process which occurs before the
   data is actually transferred across the Internet, if implemented.

   SIIPAT has several input commands (the first 6 characters of each are
   significant) that solicit various server responses.  A "burst mode"
   transmission is also supported whereas the entire authentication
   and alarm message can be sent on the initial request for the socket.
   SIIPAT also supports several status commands which can be used by the
   server to check the status of a subscriber at any time.

   The messages the subscriber equipment may send vary depending on the
   equipment in use.  Not all subscriber equipment may be capable of
   or have need to transmit all the various types of messages.  All
   servers should be capable of receiving them all however.

   Each message transmitted is prefixed by an STX character (Ascii 2)
   followed by a two character alphabetic 'Message Type' code. The
   Message Type determines what the remainder of the message contains
   as well as the length of the entire message.  All messages will
   conform to the following message format:

    <stx>    - Start of Transmission identifier (Ascii 2).
    msg type - Two character Message Type.
    length   - Two digit length of variable data to follow (01-99).
    data     - Raw data message of length characters total.
    <etx>    - End of Transmission identifier (Ascii 3).


   The server sends replies or status inquiries prefixed by an ENQ char-
   acter (Ascii 5) and terminated by an EOT (Ascii 4).
   The messages the server should be expected to return are grouped in
   the following catagories to make it easier for the subscriber equipment
   to determine the necessary action based solely on the first character.

    1xxx - Success, Proceed, Verified
    2xxx - Accepted but Incomplete
    3xxx - Authentication Error
    4xxx - Protocol Error
    5xxx - Duplicate Transmission
    8xxx - Network Busy/Error
    9xxx - Status Inquiries


   Typically, the subscriber initiates the connection with the server.
   Upon opening the connection, the server issues a "1RDY" message
   (indicating the willingness of the server to accept SIIPAT commands).
   At that point, the subscriber sends it's data stream and awaits
   a response from the server indicating the success or failure of
   the transmission.  The subscribers unit should also be capable
   of determining no response within a set time frame and resort to
   customary alarm transmision paths or attempt to contact a differant
   server at a differant IP address.

   Status messages can be initiated by the server if the subscriber
   unit supports it.  Each subscriber unit shall at minimum support
   the type 9999 server response for inquires.  The subscriber unit
   simply needs to respond with a status message with no variable
   length data supplied.  This signifies to the server that this
   host does not support/want additional status messages to be
   performed against it.  If the subscriber unit supports additional
   status messages, it will respond with the types of the status
   messages that it supports in the variable data.  This allows for
   multiple vendors equipments with differant capabilities or for
   the subscriber to limit the status inquires that can be performed
   on their unit.


4.1 Examples of "simple" SIIPAT Transmissions

   The following are two examples of how an alarm message may be
   sent to the server using SIIPAT.  Note that the data transferred
   between subscriber and server may be encrypted before it is sent
   which is not shown in these examples.

   Both these examples show the authentication of site 1234 with a
   password of PASSWORD.  Two alarm messages are being sent for the
   alarm account number of 4321, one is a code 99 and the other is
   a code 31, both using the SIIPAT 4x2 format.


4.1.1 Standard Transmission

    Subscriber                         Server
    --------------------------         -----------------------------------
    Open Connection               -->
                                  <--  1RDY17ABC ALARM COMPANYv1.00
    ID041234                      -->
                                  <--  1PW?14Enter Password
    PW08PASSWORD                  -->
                                  <--  1BGN18Begin Transmission
    AM11!!4X2432199               -->
                                  <--  1RCV11!!4X2432199
    AM11!!4X2432131               -->
                                  <--  1RCV11!!4X2432131
    CC                            -->
                                  <--  1SNT152 Messages Rcvd
    Close Connection


4.1.2 Burst Transmission

    When a burst transmission is sent, all the data is sent on one
    stream.  This stream can occur at the time of opening the connection
    or after the 1RDY message is returned depending on the subscriber
    unit and it's capabilities.


    Subscriber                         Server
    --------------------------         -----------------------------------
    Open Connection               -->
                                  <--  1RDY17ABC ALARM COMPANYv1.00
    ID041234PW08PASSWORDAM11!!4X2432199AM11!!4X2432131
                                  <--  1SNT152 Messages Rcvd
    Close Connection


4.2 Subscriber Messages

    The following sections briefly describe the possible messages that
    a subscriber unit can send.  All these messages are prefixed by
    an STX character (Ascii 2) and terminated by an ETX (Ascii 3).


4.2.1 "ID" Messages - Logon Information

    Each transmission must be authenticated against a table the server
    maintains to ensure that no tampering is being attempted.  Therefore
    each transmission must include an ID type message before actual
    messages will be acknowledged from the subscriber unit.

    ID             - Message Code.
    xx             - Length of ID to follow (01-99).
    .....          - Actual ID transmitted.
                     (This ID may or may not coincide with the
                      actual alarm number depending on preferance.)


4.2.2 "PW" Messages - Password Authentication

    In order to determine that a random ID wasn't guessed, a password
    associated with each ID must also be sent.  Whether the server
    actually verifies this information or not is normally configurable.

    PW             - Message Code.
    xx             - Length of Password to follow (01-99).
    ......         - Actual Password transmitted.


4.2.3 "MA", "MS" and "MV" Messages - Alarm Messages

    Transmission of actual data is done with Alarm Messages.  The three
    differant types of alarm messages allows the server to sort the
    messages by priority before sending them to the host computer system.

    MA             - Message Code.  (Alarm Messages)
        or MS                       (Status Messages)
        or MV                       (Verification Messages)
    xx             - Length of Raw Alarm Data (01-99).
    ........       - Actual Raw Data.

    The format of the Raw Data for Alarm Type Messages varies depending
    on the transmitting and receiving equipment.  For propeitary
    implementations this could be any format desired. It is recommended
    that the following format be used for compatibility so that
    automation software can parse the Emulated Data from the string
    and send it to the existing receiver interfaces for that type
    of receiver.  This should ensure that the most current specifications
    remain in effect for SIIPAT if the manufacturer makes additions
    to their protocol.

             !           - Identifies Emulated Data being sent
             xxxx        - Format Identifier
                of !4X1  - SIIPAT 4x1 Format
                or !4X2  - SIIPAT 4x2 Format
                or !4X3  - SIIPAT 4x3 Format
                or !CID  - SIIPAT Contact ID Format
                or ADMC  - Ademco 685 Receiver Emulation
                or DMP1  - DMP SCS1 Receiver Emulation
                or FBII  - FBII CP220 Receiver Emulation
                or ITIC  - ITI CS4000 Comp Emulation
                of ITIG  - ITI CS4000 Generic Emulation
                or RMII  - Radionics Modem II Emulation
                or RSIA  - Radionics SIA Emulation
                or SAFE  - Senses Intl. Safecom Emulation
                or SURG  - Surgard xLR Receiver Emulation
             ..........  - Emulated Data
                           (length varies depending on the format
                            and is five less than the length of
                            the Length of Raw Data specified for
                            the Alarm Message Type.)


4.2.4 "CC" Message - Close Connection

    Requests a summary from the server and once received closes the
    connection.  All subsequent transmissions from the subscriber on
    this socket are ignored.


4.2.5 "??" Message - Subscriber Status

    The server must have sent a type 9 Status Inquiry in order for
    this message to be generated.  When the server wishes to inquire
    on a subscriber, it opens the socket with the subscriber at the
    subscribers IP address and port and sends out a 9999 response.
    At that point the subscriber unit sends out a type ?? message
    indicating it's abilities for further commands.

    ??             - Message Code.
    xx             - Length of available commands (04-96)
    yyyy           - Number of the Server Inquiry that this
                     subscriber is capable of.  This is always
                     a four digit number (9000-9999) that repeats.
                     Ie:9990999199929993 would mean that this
                     subscriber is capable of type 9990-9993
                     status inquiries.


4.2.6 "CL" Message - Cancel Last Message

    When this message is received by the server, the last M type
    message received is thrown away.  This is used by subscriber
    units that detect the data sent back on the 1RCV message from
    the server was not the same as it sent.  Once a subscriber
    sends this message, it can then begin to retransmit the message.


4.3 Server Responses

    The following sections explain the various responses that a
    server can sent to the subscriber.  All these transmissions are
    started with an ENQ character (Ascii 5) and terminated with
    an EOT character (Ascii 4).

    1xxx - Success, Proceed, Verified
    2xxx - Accepted but Incomplete
    3xxx - Authentication Error
    4xxx - Protocol Error
    5xxx - Duplicate Transmission
    8xxx - Network Busy/Error
    9xxx - Status Inquiries


4.3.1 - Success, Proceed, Verified

    1RDY - Tells the subscriber that the server is ready to accept
           data and provides basic information about the server
           including the servers name and SIIPAT version number.
    1PW? - Asks the subscriber unit for a password if required by
           the server.
    1BGN - Tells the subscriber that it has been authenticated and
           it should begin transmitting signals.
    1RCV - Repeats the data received back to the subscriber.
    1CAN - The last message was cancelled as requested by a CL message.
    1SNT - Tells the subscriber that the messages were sent to the
           automation system along with a comment which usually
           indicates the number of signals received.  This message
           should be recorded by the subscriber unit for display
           as it may contain other information such as a notice
           to contact the alarm company regarding an outstanding balance
           or other informational purposes.

4.3.2 - Accepted but Incomplete

    2INC - The message sent was incomplete in some way but enough
           information was received to pass it on.  This is most
           likely caused by a message length field being set longer
           than the actual data received.


4.3.3 - Authentication Error

    3BID - The ID sent is not on file or is blacklisted on this server.
    3BPW - Bad or missing Password data was detected.
    3BIP - The ID sent is configured to only be accepted from one IP
           address, which was not the one this message was from.


4.3.4 - Protocol Error

    4ERR - An invalid Message Code was received or a message was
           missing relavent parts or incorrect data.
    4TME - Too Many Errors, closing connection.  This will only
           occur during busy socket usage when the same socket
           experiences more than three errors in a row.


4.3.5 - Duplicate Transmissions

    5DUP - The message sent is exactly the same as the previous message
           from this subscriber.  This can be caused when a server
           response is lost in replying to an alarm message and the
           subscriber tries again.  A time limit for expiration of this
           feature can be set, or it can be disabled globally.

4.3.8 - Network/Busy Errors

    8BSY - The server is too busy to handle the request now.  This
           could be performance related or by lack of sockets available.
           Every server must be capable of at least 128 concurrent
           sockets to be approved with SIIPAT.
    8HST - An error has occured with the host computer, thus making
           it impossible for this server to pass on the alarm information.
    8TIM - Timeout waiting for message from subscriber.


4.3.9 - Status Inquiries

    All Status Inquiries with the exception of 9999 return type MS
    messages.  The format of the returned message varies depending
    on what was requested.  NOTE: The subscriber units shall normally
    be configured to only accept status inquiries from a host which
    has an IP address that the subscriber unit is programmed to send
    messages to.  This prevents anyone from being able to ask a
    subscriber unit for it's status since only valid servers for that
    subscriber can request it.  Additionally, as proposed in the
    optional extensions, programming information can be relayed upon
    additional authentication of the server by the subscriber.
    Items marked with an **** require additional authentication.
    Items marked with an !!!! also require a secondary authentication.

    9000 - Return subscriber name.
    9001 - Check Alarm/Restore Status.
    9002 - Check Open/Close Status.
    9003 - Sends temporary message to subscriber to be displayed on keypad
           (displayed until next keypad event occurs).
    9004 - Changes the permanent keypad message.
    9970 - Check Zone Status ****
    9971 - Check Partition Status ****
    9980 - Arms the system. **** !!!!
    9981 - Disarms the system. **** !!!!
    9982 - Bypass zones. **** !!!!
    9994 - Return Configuration Switches. ****
    9997 - Return IP address list. ****
    9998 - Change the IP address list. **** !!!!
    9999 - Ask the subscriber for it's capabilities.  These are returned
           in an ?? type message.
    9GMT - Asks subscriber for GMT offset.
    9PNG - Returns 'PING'.
    9TM? - Returns the current date/time at subscriber unit.
    9TMS - Sets the current date/time at subscriber unit.
    9TST - Returns 'TEST'.


4.4 Illegal Commands

   Should the subscriber issue an illegal command, the server may respond in
   one of the two following ways:

    4TME Too Many Errors
    4ERR Invalid Message Code


4.5 Timeouts

   The SIIPAT server can optionally have an inactivity timeout
   implemented.  At the expiration of the allotted time, the server
   responds "8TIM Timeout" and closes the connection.


5. Author

   Steven M. Ryckman, Technical Supervisor
   Security Information & Management Systems, Inc.
   3112 Teakwood Lane - C.S.M. Division
   Plano, Texas   USA   75075

   Voice: 972-964-7019
     Fax: 972-964-0902
   Email: sryckman@pobox.com


6. Additional Information

   For more information regarding SIIPAT, contact Steve Ryckman by one of
   the above listed methods (preferably by email).  A "home page" has
   also been established with additional information on SIIPAT at
   the following URL:  http://pobox.com/~sims.support/siipat.html