UIT-T Rec. Z.100 (11/99) SDL: langage de description et de ...
Data encoding for SDL in ITU-T Rec . Z.104
description
Transcript of Data encoding for SDL in ITU-T Rec . Z.104
![Page 1: Data encoding for SDL in ITU-T Rec . Z.104](https://reader036.fdocuments.net/reader036/viewer/2022062321/56813fe7550346895daad684/html5/thumbnails/1.jpg)
SDL Forum Society
SDL and MSC (SAM) workshop , Ottawa, 01-04 June 2004
Data encoding for Data encoding for SDL in ITU-T SDL in ITU-T RecRec. .
Z.104Z.104
Rick ReedTSE Ltd
![Page 2: Data encoding for SDL in ITU-T Rec . Z.104](https://reader036.fdocuments.net/reader036/viewer/2022062321/56813fe7550346895daad684/html5/thumbnails/2.jpg)
SDL and MSC (SAM) workshop , Ottawa, 01-04 June 2004
Purpose
Define data encoding for
o Communication between
components
o Implementation by different tools
• Versions
• Platform variations
o Calculation/control of signal sizes
![Page 3: Data encoding for SDL in ITU-T Rec . Z.104](https://reader036.fdocuments.net/reader036/viewer/2022062321/56813fe7550346895daad684/html5/thumbnails/3.jpg)
SDL and MSC (SAM) workshop , Ottawa, 01-04 June 2004
Z.104 features (1)
o Encode SDL data to a text string
o Encode ASN.1 based data
• According to X.690 series
• Must be
• CHOICE• Signal names = choice names
• As BIT STRING, OCTET STRING
o Object (reference) data not supported
![Page 4: Data encoding for SDL in ITU-T Rec . Z.104](https://reader036.fdocuments.net/reader036/viewer/2022062321/56813fe7550346895daad684/html5/thumbnails/4.jpg)
SDL and MSC (SAM) workshop , Ottawa, 01-04 June 2004
Z.104 features (2)
o Encoding on communication paths
o Implicit interfaces + signals from ASN.1
o Input, analyse, store encoded messages
o Output signals from encoded message
o Encode signal to encoded message
o Decode signal from encoded message
o Implied data definitions
o ASN.1 implied interface definition
![Page 5: Data encoding for SDL in ITU-T Rec . Z.104](https://reader036.fdocuments.net/reader036/viewer/2022062321/56813fe7550346895daad684/html5/thumbnails/5.jpg)
SDL and MSC (SAM) workshop , Ottawa, 01-04 June 2004
o package Predefined
o 1 There are 4 variations of PER• Aligned and Unaligned to Octet• ‘Basic’ and Canonical
o The choice of PER name(s) is tbd.
Encoding rules
![Page 6: Data encoding for SDL in ITU-T Rec . Z.104](https://reader036.fdocuments.net/reader036/viewer/2022062321/56813fe7550346895daad684/html5/thumbnails/6.jpg)
SDL and MSC (SAM) workshop , Ottawa, 01-04 June 2004
The Q.921 ExampleEncoding on gate
Encoding on channel
Encoding on • gate ServiceUser
• channel peer_to_peer_connection
![Page 7: Data encoding for SDL in ITU-T Rec . Z.104](https://reader036.fdocuments.net/reader036/viewer/2022062321/56813fe7550346895daad684/html5/thumbnails/7.jpg)
SDL and MSC (SAM) workshop , Ottawa, 01-04 June 2004
Path with encode:Implied data types
Implied by
encode
Encoding datatype
Implied datatype forDL_data_reqparameters
Implied datatype forDL_unit_data_ _req
parameters
![Page 8: Data encoding for SDL in ITU-T Rec . Z.104](https://reader036.fdocuments.net/reader036/viewer/2022062321/56813fe7550346895daad684/html5/thumbnails/8.jpg)
SDL and MSC (SAM) workshop , Ottawa, 01-04 June 2004
Encoded path Input + Output
decoded from gate
encoded for gate
o No special syntax for input/outputo Encoding only in Userside context
![Page 9: Data encoding for SDL in ITU-T Rec . Z.104](https://reader036.fdocuments.net/reader036/viewer/2022062321/56813fe7550346895daad684/html5/thumbnails/9.jpg)
SDL and MSC (SAM) workshop , Ottawa, 01-04 June 2004
Text encoding
o Boolean, Character, Charstring, Integer, Real, Duration, Time, Bit, Bitstring, Octetstring, NULL
o String, Array, Vector, Powerset, Bag, STRUCT, CHOICE, enumerated types
o Pid, pid types• ApplicationDefined, Integer,
Octetstring, Bitstring, Charstring and a composite {struct identity Charstring; instance
Natural}
o Object - not supported
Basic types
Composite types
Processing identity types
![Page 10: Data encoding for SDL in ITU-T Rec . Z.104](https://reader036.fdocuments.net/reader036/viewer/2022062321/56813fe7550346895daad684/html5/thumbnails/10.jpg)
SDL and MSC (SAM) workshop , Ottawa, 01-04 June 2004
Encoding a signal as text
oSignal
oEncoding
Commas separate parametersText is not intended to be human readable
signal parameter list
parameter struct start
parameter struct end
signal startsignal end
![Page 11: Data encoding for SDL in ITU-T Rec . Z.104](https://reader036.fdocuments.net/reader036/viewer/2022062321/56813fe7550346895daad684/html5/thumbnails/11.jpg)
SDL and MSC (SAM) workshop , Ottawa, 01-04 June 2004
Missing Parameters and Null
o DL_data_req with no parameters• {2,{}}
o Data type NULL(such as DL_release_req)
• {1,0}
• {1,}
• {1}
Full encoding
Omit NULL parameter
No parameter
![Page 12: Data encoding for SDL in ITU-T Rec . Z.104](https://reader036.fdocuments.net/reader036/viewer/2022062321/56813fe7550346895daad684/html5/thumbnails/12.jpg)
SDL and MSC (SAM) workshop , Ottawa, 01-04 June 2004
USE ASN.1+Implicit Interface
ASN.1 definition
package use
Clause for ASN.1
Implied interface
and signals
![Page 13: Data encoding for SDL in ITU-T Rec . Z.104](https://reader036.fdocuments.net/reader036/viewer/2022062321/56813fe7550346895daad684/html5/thumbnails/13.jpg)
SDL and MSC (SAM) workshop , Ottawa, 01-04 June 2004
Using ASN.1 on a path
o USE implies Peer_to_peer interfaceo Interface with encoding implies
data types for encoding
Using the implied interface
![Page 14: Data encoding for SDL in ITU-T Rec . Z.104](https://reader036.fdocuments.net/reader036/viewer/2022062321/56813fe7550346895daad684/html5/thumbnails/14.jpg)
SDL and MSC (SAM) workshop , Ottawa, 01-04 June 2004
Input without decode
Communication path
string variable encoded data
Explanation in terms of receiving a value then encoding a signal
implicit decode
![Page 15: Data encoding for SDL in ITU-T Rec . Z.104](https://reader036.fdocuments.net/reader036/viewer/2022062321/56813fe7550346895daad684/html5/thumbnails/15.jpg)
SDL and MSC (SAM) workshop , Ottawa, 01-04 June 2004
Output of encoded message
Explanation in terms of decoding the signal from stored data, followed by output
Communication path
string for encoded data
implicit encode
![Page 16: Data encoding for SDL in ITU-T Rec . Z.104](https://reader036.fdocuments.net/reader036/viewer/2022062321/56813fe7550346895daad684/html5/thumbnails/16.jpg)
SDL and MSC (SAM) workshop , Ottawa, 01-04 June 2004
ENCODE/DECODE expressions
o DECODE stored string from inputo ENCODE to string for outputo Can be used for encapsulationo May require dummy gates
![Page 17: Data encoding for SDL in ITU-T Rec . Z.104](https://reader036.fdocuments.net/reader036/viewer/2022062321/56813fe7550346895daad684/html5/thumbnails/17.jpg)
SDL and MSC (SAM) workshop , Ottawa, 01-04 June 2004
Conclusion
o Some limitations - possible extensions• Other encoding rules (such as XER)• Application defined encoding rules• Input ENCODE when no rule on path• Output/encode from string expression• Output/encode from CHOICE expression• Other data formalisms than ASN.1• X.690 support for SDL
o Feedback requested (by 15th July 2004)
o Consent for approval 19-21July 2004