INTERNET-DRAFT EXPIRES: FEB 1998 INTERNET-DRAFT
N.S.C Working Group A.Robert
INTERNET-DRAFT SITA
June 1997
MAPPING OF AIRLINE TRAFFIC OVER IP
<draft-rfced-info-robert-00.txt>
Status of this Memo
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
time. It is inappropriate to use Internet-Drafts as reference material
or to cite them other than as "work in progress".
To view the entire list of current Internet-Drafts, please check the
"1id-abstracts.txt" listing contained in the Internet-Drafts Shadow
Directories on ftp.is.co.za (Africa), ftp.nordu.net (Europe),
munnari.oz.au (Pacific Rim), ds.internic.net (US East Coast), or
ftp.isi.edu (US West Coast).
Abstract
This memo specifies a protocol for the encapsulation of the airline
specific protocol over IP.
Contents
1. INTRODUCTION 3
2. TERMINOLOGY & ACRONYMS 4
3. LAYERING 6
4. TRAFFIC IDENTIFICATION 7
5. TCP PORT ALLOCATION 7
6. MATIP SESSION ESTABLISHMENT 7
7. OVERALL PACKET FORMAT FOR TYPE A & TYPE B 9
8. MATIP FORMAT FOR TYPE A CONVERSATIONAL TRAFFIC 10
8. 1 Control Packet Format 10
8.1.1 Session Open format (SO) 10
8.1.2 Open Confirm format (OC) 12
SITA [Page 1]
I/D Mapping of Airline Traffic over IP June 1997
8.1.3 Session Close (SC) 13
8.2 Data Packet Format 14
9. MATIP FORMAT FOR TYPE A HOST-TO-HOST TRAFFIC 15
9. 1 Control Packet Format 15
9.1.1 Session Open format (SO) 15
9.1.2 Open Confirm format (OC) 17
9.1.3 Session Close (SC) 17
9.2 Data Packet Format 18
10. MATIP FORMAT FOR TYPE B TRAFFIC 19
10.1 Control packet format 19
10.1.1 Session Open format (SO) 19
10.1.2 Open confirm format (OC) 20
10.1.3 Session Close (SC) 21
10.2 Data packet format 21
11. SECURITY 22
12. AUTHOR ADDRESS 22
SITA [Page 2]
I/D Mapping of Airline Traffic over IP June 1997
1. Introduction
Most airlines are willing to migrate from airline specific protocols
to standardized protocols in order to benefit from the lower cost of
new technologies, but the migration has been slow done to the
following factors:
- Applications have not been migrated.
- Dumb terminals using airline protocols P1024B (IBM ALC) or P1024C
(UNISYS UTS) are still numerous.
There are currently many different proprietary solutions based on
gateways available to take advantage of low cast networking, but they
are not scaleable and cannot interact.
In the future, TCP/IP will be more commonly used as a common transport
means for traffic types because:
- TCP/IP is the standard protocol of UNIX based applications
- TCP/IP stacks are inexpensive
- TCP/IP is used on intranets.
The purpose of this memo is to define the mapping of the airline
traffic types over TCP/IP. The airlines implementing it in their
systems should have a TCP/IP stack to enable the traffic exchange
below :
!----! ( )
! !----------( )
!----! ( )
Type B HOST ( NETWORK )
( )
( ) !---o
!----! ( )--------! D !---o Type A stations
!----!----------( ) !---o
!----! ( )
TYPE A HOST !
!
!
!
--------
! !
--------
Network Messaging System
(D) : Gateway TYPE A router
SITA [Page 3]
I/D Mapping of Airline Traffic over IP June 1997
The different airline traffic flows concerned by this memo are :
- TYPE A Host / Terminal
- TYPE A Host / TYPE A host
- TYPE B Host / Network messaging System
In the case of dumb terminals, a conversion is required on the
terminal side in order to have an IP connection between the host and
the router. However, the IP connection is directly between the central
airline host and the intelligent workstation if the latter has a
direct connection to the network, a TCP/IP stack and a terminal
emulation
2. Terminology & acronyms
ALC :
Airline Line Control: IBM airline specific protocol (see P1024B)
ASCII
American Standard Code for Information Interchange
ASCU
Agent Set Control Unit: Cluster at the user side.
AX.25
Airline X.25 : Airline application of the X.25 OSI model (published by
IATA)
BATAP
Type B Application to Application Protocol. Protocol to secure the
TYPE B traffic. It was specified by SITA and is now published by IATA
(SCR Vol. 3)
EBCDIC
Extended Binary Coded Decimal Interchange Code
Flow ID Traffic
Flow identifier used in host to host traffic to differentiate traffic
flow types.
HLD
High Level Designator: Indicates the entry or exit point of a block in
the network.
SITA [Page 4]
I/D Mapping of Airline Traffic over IP June 1997
IA
Interchange Address: ASCU identifier in P1024B protocol.
IATA
International Air Transport Association
IP
Internet Protocol
IPARS
International Program Airline Reservation System: IPARS code is used
in ALC
LSB
Least Significant Bit
MATIP
Mapping of Airline Traffic over Internet Protocol
MSB
Most Significant Bit
OC
Open Confirm (MATIP command)
OSI
Open Standard Interface
P1024B
SITA implementation of the ALC, the IBM airlines specific protocol. It
uses 6- bit padded characters (IPARS) and IA/ TA for physical
addressing.
P1024C
SITA implementation of the UTS, the UNISYS terminal protocol. It uses
7-bit (ASCII) characters and RID/ SID for physical addressing.
RFU
Reserved for Future Use
RID
Remote Identifier: ASCU identifier in P1024C protocol.
SC
Session Close (MATIP command)
SID
Station Identifier: Terminal identifier in P1024C protocol.
SITA [Page 5]
I/D Mapping of Airline Traffic over IP June 1997
SITA
Societe International de Telecommunications Aeronautiques
SO
Session Open (MATIP command)
TA
Terminal Address: Terminal identifier in P1024B protocol.
TCP
Transport Control Protocol
TYPE A Traffic
Interactive traffic or host to host
TYPE B Traffic
Messaging traffic in IATA compliant format with high level of
reliability
UTS
Universal Terminal System by Unisys: (see P1024C)
3. LAYERING
MATIP is an end to end protocol. Its purpose is to have a mapping
standard between the TCP layer and the airline application without any
routing element..
+-------------------------------+
|Airline TYPE A | Airline TYPE B|
| Application | Application |
+-------------------------------+
| MATIP A | MATIP B |
+-------------------------------+
| T.C.P |
+-------------------------------+
| I.P |
+-------------------------------+
| MEDIA |
+-------------------------------+
SITA [Page 6]
I/D Mapping of Airline Traffic over IP June 1997
4. TRAFFIC IDENTIFICATION
There are two types of traffic:
TYPE A traffic:
Typically conversational traffic that could be exchanged between a
terminal and an airline host or between two airline hosts.
TYPE B traffic :
For message exchange between an airline host and a TYPE B Message
Switching System.
In TYPE A conversational traffic, the airline host application
recognizes the ASCU thanks to 4 bytes (H1, H2, A1, A2). These bytes
are assigned by the host and are unique per ASCU. Thus, a host can
dynamically recognize the ASCU independent of IP address.
H1 H2 A1 A2 bytes follow one of the three cases below:
- A1,A2 only are used and H1H2 is set to 0000.
- H1,H2 identify the session and A1A2 the ASCU inside the session.
- H1,H2,A1,A2 identify the ASCU.
The first two cases are fully compatible with the AX.25 mapping where
H1H2 may be equivalent to the HLD of the concentrator, i.e., 2 bytes
hexadecimal. The third rule allows more flexibility but is not
compatible with AX.25.
In TYPE A host to host traffic the identification field is also
present and is equal to 3 bytes H1 H2 Flow ID (optional). H1H2 are
reserved for remote host identification (independently of the IP
address) and must be allocated bilaterally.
In Type B traffic, identification of End Systems may be carried out by
the use of HLDs, or directly by the pair of IP addresses.
5. TCP PORT ALLOCATION
IANA (Internet Assigned Numbers Authority) has allocated the following
ports for MATIP TYPE A and TYPE B traffic:
MATIP Type A TCP port = 350
MATIP Type B TCP port = 351
Therefore the traffic type A or B is selected according to the TCP port.
6. MATIP SESSION ESTABLISHMENT
SITA [Page 7]
I/D Mapping of Airline Traffic over IP June 1997
Prior to any exchange between two applications, a unique MATIP session
is established above the TCP connection in order to identify the
traffic characteristic such as:
- Subtype of traffic for TYPE A (Type A host to host or Type A
conversational )
- Multiplexing used (for Type A)
- Data header
- Character set
A separate session must be established for each set of parameters
(e.g., P1024B, P1024C traffic between two points needs two separate
sessions).
The establishment of a MATIP session can be initiated by either side.
No keep-alive mechanism is defined at MATIP level. Session time out
relies on the TCP time-out parameters.
There are three commands defined to manage the MATIP session:
- Session Open (SO) to open a session.
- Open Confirm (OC) to confirm the SO command.
- Session close (SC) to close the current session.
A MATIP session can be up only if the associated TCP connection is up.
However it is not mandatory to close the TCP connection when closing
the associated MATIP session.
Typical exchange is:
TCP session establishment
Session Open --------->
<----------- Open confirm
data exchange
---------------------->
<-------------------------
.
.
.
Session Close ----------------->
.
.
.
<------------------------- Session Open
Open confirm ------------------->
data exchange
<-------------------------
---------------------->
SITA [Page 8]
I/D Mapping of Airline Traffic over IP June 1997
The open session command may contain configuration elements.
An open session command received on a session already opened (i.e. same
IP address and port number) will automatically clear the associated
configuration and a new configuration will be set up according to the
information contained in the new open session command.
As illustrated above, the open and close commands are symmetrical.
For type A conversational traffic, the SO and OC commands contain
information for the identification of the ASCUs and the session. ASCUs
are identified within a session by two or 4 bytes. A flag is set to
indicate if the ASCU is identified by 4 bytes (H1H2A1A2) or by 2 bytes
(A1A2). In the latter case, H1H2 is reserved for session identification.
The SO command is sent to open the MATIP session. In Type A
conversational it may contains the list of ASCUs configured in this
session.
The OC command confirms the SO command. It can refuse or accept it,
totally or conditionally. In Type A, it contains the list of the ASCUs
either rejected or configured in the session.
7. OVERALL PACKET FORMAT FOR TYPE A & TYPE B
The first 4 bytes of the MATIP header follow the following rules.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0|0|0|0|0| Ver |C| Cmd | length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Ver
The `Ver' (Version) field represents the version of the MATIP. It must
contain the value 001 otherwise the packet is considered as invalid.
C
Identifies a CONTROL packet.
When set to 1, the packet is a Control packet
When set to 0, the packet is a Data packet
Cmd
This field identifies the control command if the flag C is set to 1.
Length
SITA [Page 9]
I/D Mapping of Airline Traffic over IP June 1997
This byte indicates the number of bytes of the whole command, header
included.
Notes : Fields identified as optional (Opt) are not transmitted if not
used.
8. MATIP FORMAT FOR TYPE A CONVERSATIONAL TRAFFIC
8. 1 Control Packet Format
There are 3 control packets to open or close the session at the MATIP
level.
8.1.1 Session Open format (SO)
To be able to identify the session and before sending any data
packets, a Session Open command is sent. It can be initiated by either
side. In case of collision, the open session from the side having the
lower IP address is ignored.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0|0|0|0|0| Ver |1|1 1 1 1 1 1 0| length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0 0|0 1|0| CD | STYP |0 0 0 0| RFU |MPX|HDR| PRES. |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| H1 | H2 | RFU |
|-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved | RFU | Nbr of ASCUs |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Nbr of ASCUs | ASCU list (opt) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
RFU
Reserved for future use. Must be set to zero.
CD
This field specifies the Coding
000 : 5 bits (padded baudot)
010 : 6 bits (IPARS)
100 : 7 bits (ASCII)
110 : 8 bits (EBCDIC)
SITA [Page 10]
I/D Mapping of Airline Traffic over IP June 1997
xx1 : R.F.U
STYP
This is the traffic subtype (type being TYPE A).
0001 : TYPE A Conversational
MPX
This flag specifies the multiplexing used within the TCP session.
Possible values are:
00 : Group of ASCU with 4 bytes identification per ASCU (H1H2A1A2)
01 : Group of ASCUs with 2 bytes identification per ASCU (A1A2)
10 : single ASCU inside the TCP session.
HDR
This field specifies which part of the airline's specific address is
placed ahead of the message texts transmitted over the session.
Possible values are :
00 : ASCU header = H1+H2+A1+A2
01 : ASCU Header = A1+A2
10 : No Header
11 : Not used
The MPX and HDR must be coherent. When ASCUs are multiplexed, the data
must contain the ASCU identification. The table below summarizes the
allowed combinations :
+--------------------------+
| MPX | 00 | 01 | 10 |
+--------------------------+
| HDR | |
| 00 | Y | Y | Y |
| 01 | N | Y | Y |
| 10 | N | N | Y |
+--------------------------+
PRES
This field indicates the presentation format
0001 : P1024B presentation
0010 : P1024C presentation
0011 : 3270 presentation
H1 H2
These fields can logically identify the session if MPX is not equal to
00. When this field is not used, it must be set to 0. If used in
SITA [Page 11]
I/D Mapping of Airline Traffic over IP June 1997
session (MPX <> 0) with HDR=00, H1H2 in data packet must have the same
value as set in SO command.
Nbr of ASCUs
Nbr_of_ASCUs field is mandatory and gives the number of ASCUs per
session. A 0 (zero) value means unknown. In this case the ASCU list is
not present in the `Open Session' command and must be sent by the
other end in the `Open Confirm' command.
ASCU LIST
Contains the list of identifier for each ASCU. If MPX=00 it has a
length of four bytes (H1H2A1A2) for each ASCU, otherwise it is two
bytes (A1A2).
8.1.2 Open Confirm format (OC)
The OC (Open Confirm) command is a response to an SO (Session Open)
command and is used to either refuse the session or accept it
conditionally.
In case of acceptance, the OC indicates the number and the address of
the rejected ASCUs, if any. Alternatively, it indicates the list of
ASCUs configured for that MATIP session if the list provided by the SO
command was correct or the number of ASCUs configured in the session
was unknown (n. of ASCU equals 0).
8.1.2.1 Refuse the connection
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0|0|0|0|0| Ver |1|1 1 1 1 1 0 1|0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 1|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0 1| cause |
+-+-+-+-+-+-+-+-+
Cause
This field indicates the reason for the MATIP session refusal :
0 0 0 0 0 1 : No Traffic Type matching between Sender & Recipient
0 0 0 0 1 0 : Information in SO header incoherent
8.1.2.2 Accept the connection
SITA [Page 12]
I/D Mapping of Airline Traffic over IP June 1997
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0|0|0|0|0| Ver |1|1 1 1 1 1 0 1| length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0 0 R 0 0 0 0 0| Nbr of ASCUs |Nbr of ASCU(opt| ASCU LIST |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
R
Flag indicating an error in the ASCU configuration provided in the SO
command.
NBR of ASCUs
If the MPX value is equal to 00 in the SO command, this field is two
bytes long. Otherwise, it is one byte.
If the R flag is set, the Nbr_of_ASCUs field represents the number of
ASCUs in error. Otherwise, it indicates the number of ASCUs configured
for that MATIP session.
ASCU LIST
Depending on the R flag, this field indicates the list of ASCUs (A1A2
or H1H2A1A2) either in error or within the session.
8.1.3 Session Close (SC)
The SC (Session Close) command is used to close an existing MATIP
session.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0|0|0|0|0| Ver |1|1 1 1 1 1 0 0|0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 1|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Close Cause |
+-+-+-+-+-+-+-+-+
Close Cause
Indicates the reason for the session closure:
SITA [Page 13]
I/D Mapping of Airline Traffic over IP June 1997
0 0 0 0 0 0 0 0 : Normal Close
1 0 0 0 0 1 0 0
up to Application dependent
1 1 1 1 1 1 1 1
8.2 Data Packet Format
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0|0|0|0|0| Ver |0|0 0 0 0 0 0 0| length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ID (optional) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| Payload |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
ID
This field is optional and has a different length and format according
to the value of HDR, PRES indicated during the session
establishment.
HDR
This field is depending on the PRESENTATION :
+------------------------------+-------------------------------+
|HDR | PRES = P1024B and 3270 | PRES = P1024C |
+------------------------------+-------------------------------+
|00 |ID = 4 bytes H1-H2-A1-A2 | ID = 5 bytes H1-H2-A1-0x01-A2 |
+------------------------------+-------------------------------+
|01 |ID = 2 bytes A1-A2 | ID = 3 bytes A1-0x01-A2 |
+------------------------------+-------------------------------+
|10 |ID = 0 bytes | ID = 0 bytes |
+------------------------------+-------------------------------+
H1, H2 value must match the value given in the SO command if MPX is
different from 0.
Payload
SITA [Page 14]
I/D Mapping of Airline Traffic over IP June 1997
payload begins with the terminal identification :
- One byte Terminal identifier (TA) in P1024B
- Two bytes SID/DID Terminal identifier in P1024C.
9. MATIP FORMAT FOR TYPE A HOST-TO-HOST TRAFFIC
9. 1 Control Packet Format
There are 3 control packets to open or close the session at the MATIP
level.
9.1.1 Session Open format (SO)
To be able to identify the session and before sending any data packet,
a Session Open command is sent. It can be initiated by either side. In
case of collision, the open session from the side having the lower IP
address is ignored.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0|0|0|0|0| Ver |1|1 1 1 1 1 1 0| length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0 0|0 1|0| CD | STYP |0 0 0 0| RFU |MPX|HDR|0 0 0 0|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| H1 | H2 | RFU |
|-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flow ID(opt)|
+-+-+-+-+-+-+-+-+
RFU
Reserved for future use. Must be set to zero.
CD
This field specifies the Coding, as defined in section 8.1.1.1.
STYP
This is the traffic subtype (type being Type A).
0010 : TYPE A IATA Host to Host
SITA [Page 15]
I/D Mapping of Airline Traffic over IP June 1997
1000 : SITA Host to Host
MPX
This flag specifies the multiplexing used within the TCP session in
TYPE A SITA host to host. Possible values are:
00 : irrelevant
01 : multiple flow inside the TCP connection
10 : single flow inside the TCP connection
HDR
This field specifies which part of the airline's specific address is
placed ahead of the message text transmitted over the session.
Possible values are :
00 : used in TYPE A SITA Host to Host Header = H1+H2+Flow ID
01 : used in TYPE A SITA Host to Host Header = Flow ID
10 : No Header (default for IATA host to Host)
11 : Not used
The MPX and HDR must be coherent. When flow are multiplexed, the data
must contain the flow identification. The table below summarizes the
possible combinations:
+---------------------+
| MPX | 01 | 10 |
+---------------------+
| HDR | | |
| 00 | Y | Y |
| 01 | Y | Y |
| 10 | N | Y |
+---------------------+
H1 H2
These fields can be used to identify the session. When this field is
not used, it must be set to 0. If HDR=00, H1H2 in data packet must
have the same value as set in SO command.
Flow ID
This field is optional and indicates the Flow ID (range 3F - 4F Hex).
SITA [Page 16]
I/D Mapping of Airline Traffic over IP June 1997
9.1.2 Open Confirm format (OC)
The OC (Open Confirm) command is a response to an SO (Session Open)
command and is used to either refuse the session or accept it.
9.1.2.1 Refuse the connection
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0|0|0|0|0| Ver |1|1 1 1 1 1 0 1|0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 1|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0 1| cause |
+-+-+-+-+-+-+-+-+
Cause
This field indicates the reason for the MATIP session refusal
0 0 0 0 0 1 : No Traffic Type matching between Sender & Recipient
0 0 0 0 1 0 : Information in SO header incoherent
9.1.2.2 Accept the connection
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0|0|0|0|0| Ver |1|1 1 1 1 1 0 1|0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 1|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0 0 0 0 0 0 0 0|
+-+-+-+-+-+-+-+-+
9.1.3 Session Close (SC)
The SC (Session Close) command is used to close an existing MATIP
session.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0|0|0|0|0| Ver |1|1 1 1 1 1 0 0|0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 1|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Close Cause |
+-+-+-+-+-+-+-+-+
SITA [Page 17]
I/D Mapping of Airline Traffic over IP June 1997
Close Cause
Indicates the reason for the session closure:
0 0 0 0 0 0 0 0 : Normal Close
1 0 0 0 0 1 0 0
up to : Application dependent
1 1 1 1 1 1 1 1
9.2 Data Packet Format
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0|0|0|0|0| Ver |0|0 0 0 0 0 0 0| length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ID (optional) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| Payload |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
ID
This field is optional and has a different length and format according
to the value of HDR indicated during the session establishment.
HDR
+-------------------------------+
|HDR | I.D. |
+-------------------------------+
|00 |ID = 3 bytes H1-H2 FLOW ID|
+-------------------------------+
|01 |ID = FLOW ID |
+-------------------------------+
|10 |ID nor present |
+-------------------------------+
SITA [Page 18]
I/D Mapping of Airline Traffic over IP June 1997
Payload packet
The payload format is transparent to the MATIP layer. It is formatted
according to the IATA host to host specifications and agreed
bilaterally by the sender and the receiver.
10. MATIP FORMAT FOR TYPE B TRAFFIC
10.1 Control packet format
There are 3 control packets used to open or close the session at the
MATIP level for exchanging Type B data
10.1.1 Session Open format (SO)
Before sending any data packets, it is recommended to check that the
systems which are establishing a session are indeed able to
communicate (i.e.: Both systems agree on the characteristics of the
traffic that will cross the connection). For this purpose, a two way
handshake, using the Session commands defined hereafter, is carried
out immediately after the establishment of the TCP level connection.
Either side can initiate this procedure. In case of collision, the
open session from the side having the lower IP address is ignored.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0|0|0|0|0| Ver |1|1 1 1 1 1 1 0| length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0 0 0 0|0| C D | PROTEC| BFLAG | Sender HLD |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Recipient HLD |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Length
This byte indicates the number of bytes of the whole command, header
included. The only possible lengths are : 6 bytes and 10 bytes.
CD
This field specifies the Coding, as defined in section 8.1.1.1.
PROTEC
SITA [Page 19]
I/D Mapping of Airline Traffic over IP June 1997
Identifies the end to end Messaging Responsibility Transfer protocol
used.
0010: BATAP
All other values available.
BFLAG
0 0 0 0 means that the fields `Sender HLD, Recipient HLD' do not exist
in this packet. In this case, the exact length of the packet is 6
Bytes.
0 0 1 0 means that the `Sender HLD, Recipient HLD' are carried
respectively in bytes 9,10 and 11,12 of this packet. In this case, the
exact length of the packet is 10 Bytes.
Sender HLD
HLD of the Type B System sending the Open Session.
Recipient HLD
HLD of the Type B system to which session opening is destined.
10.1.2 Open confirm format (OC)
The OC (Open Confirm) command is a response to an SO (Session Open)
command and is used to either refuse the session or accept it.
10.1.2.1 Refuse the connection
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0|0|0|0|0| Ver |1|1 1 1 1 1 0 1|0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 1|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Cause |
+-+-+-+-+-+-+-+-+
Length of this packet is 5 Bytes.
Cause
Indicates the cause of the rejection
0 1 0 0 0 0 0 1 : No Traffic Type matching between Sender & Recipient
0 1 0 0 0 0 1 0 : Information in SO header incoherent
0 1 0 0 0 0 1 1 : Type of Protection mechanism are different
0 1 0 0 0 1 0 0 up to 0 1 1 1 1 1 1 1 : R.F.U
SITA [Page 20]
I/D Mapping of Airline Traffic over IP June 1997
10.1.2.2 Accept the connection
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0|0|0|0|0| Ver |1|1 1 1 1 1 0 1|0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 1|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0 0 0 0 0 0 0 0|
+-+-+-+-+-+-+-+-+
Length of this packet is 5 Bytes.
10.1.3 Session Close (SC)
The SC (Session Close) command is used to close an existing MATIP
session.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0|0|0|0|0| Ver |1|1 1 1 1 1 0 0|0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 1|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Close Cause |
+-+-+-+-+-+-+-+-+
Close Cause
Indicates the reason for the session closure:
0 0 0 0 0 0 0 0 : Normal Close
1 0 0 0 0 1 0 0 up to 1 1 1 1 1 1 1 1 : Application dependent
10.2 Data packet format
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0|0|0|0|0| Ver |0|0 0 0 0 0 0 0| length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| Payload |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Length
SITA [Page 21]
I/D Mapping of Airline Traffic over IP June 1997
This byte indicate the number of bytes of the whole packet, header
included.
Payload
Type B message formatted according to the IATA standard and conforming
to the rules of the accessed Type B service.
11. Security
This memo raises no security issues.
12. Author address
Alain Robert
S.I.T.A.
18, rue Paul Lafargue
92904 PARIS LA DEFENSE 10
FRANCE
Phone : 33 1 46411491
Fax : 33 1 46411277
Email : arobert@par1.par.sita.int
INTERNET-DRAFT EXP: FEB 1998 INTERNET-DRAFT