Ttcn 3 and asn 1 interworking
This presentation is the property of its rightful owner.
Sponsored Links
1 / 16

TTCN-3 and ASN.1 interworking PowerPoint PPT Presentation


  • 61 Views
  • Uploaded on
  • Presentation posted in: General

TTCN-3 and ASN.1 interworking. Analysis of backward compatibility in ASN.1. Géza Horváth [email protected] TTCN-3 User Conference 20 11 7 – 9 June 2011 - Bled, Slovenia. Introduction. Nokia Siemens Networks Joint Venture of Nokia and Siemens Started operations on April 1, 2007

Download Presentation

TTCN-3 and ASN.1 interworking

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Ttcn 3 and asn 1 interworking

TTCN-3 and ASN.1 interworking

Analysis of backward compatibility in ASN.1

Géza Horváth

[email protected]

TTCN-3 User Conference 2011

7 – 9 June 2011 - Bled, Slovenia


Ttcn 3 and asn 1 interworking

Introduction

  • Nokia Siemens Networks

  • Joint Venture of Nokia and Siemens

  • Started operations on April 1, 2007

  • 65,000+ employees

  • 75 of top 100 operators worldwide

  • 150 countries

  • 3 billion mobile subscribers and ¼ of

  • world’s voice households served

  • Géza Horváth

  • Release 4 Product Support Engineer


Ttcn 3 and asn 1 interworking

Agenda

Concept of ASN.1 – TTCN-3

Compatibility of ASN.1

Planning a comparator tool

Result, future


Asn 1 introduction

ASN.1 introduction

  • Vendor- and language-independent

  • Recursive notation for complex data types

  • Avoid the transfer of concrete syntax

  • Encoding rules


Using asn 1 with ttcn 3

Using ASN.1 with TTCN-3

  • TTCN-3 provides a clean interface for using ASN.1 specifications: ETSI ES 201 873-7

  • Alternative data type and value syntax

  • Implicit mapping: import

  • Internal representation of imported objects

  • Without any lost information


Ttcn 3 and asn 1 interworking

Agenda

Concept of ASN.1 – TTCN-3

Compatibility of ASN.1

Planning a comparator tool

Result, future


The need of asn 1 compatibility

The need of ASN.1 compatibility

  • INTEGER(1..10)

  • INTEGER(1..10,...)

  • Extension marker ”...”

    • Specification v2 must include v1

  • Two compatible specifications are not necessarily syntactically identical

  • Syntactic differences should be detected

  • Semantics are very bound to syntax

  • Two distinct specifications of the same protocol can be compared to evaluate the impact on the interface


Syntactic compatibility between asn 1 specifications

Syntactic compatibility between ASN.1 specifications

  • OPTIONAL keyword

  • Extensible subtyping constraints

  • Permutation of SET components

  • What if v1 does not send the INTEGER to v2?

  • What if v2 sends the value 11 to v1?

  • Without the extensions marker?

  • We should know all the changes on the interface

  • In case of SEQUENCE?


Ttcn 3 and asn 1 interworking

Agenda

Concept of ASN.1 – TTCN-3

Compatibility of ASN.1

Planning a comparator tool

Result, future


Structure of the comparator

Structure of the comparator

  • Parser: syntactic error messages as well

  • Normalization: avoiding circular definitions

  • Transitive closure: checking references, imports


Comparator algorithm

Root

Root

PDU 1

PDU 1

statement 1

statement 1

statement 2

statement 2

PDU 2

PDU 2

Comparator algorithm

  • A diff-like (textual) algorithm?

  • Detailed comparison algorithm on graphs!

  • The goal is the find a matching between two trees

  • Nodes of the two trees are numbered

  • A global default mark is assigned to the root

  • It is divided between each branch of the root, and so on recursively

  • According to how each node matches with the corresponding one

    • The mark is inherited completely or

    • Decreased portionally to the result of the comparison


Comparator algorithm1

Comparator algorithm

  • Synthesised mark at highest level can be considered as the global level of syntactic mapping

  • Compare each PDU of v1 to all PDU of v2 to determine the best matching


Ttcn 3 and asn 1 interworking

Agenda

Concept of ASN.1 – TTCN-3

Compatibility of ASN.1

Planning a comparator tool

Result, future


Result

Result

  • Simple semantic deductions based on syntactic differences

    • *Only notice, not incompatibility

    • **In some cases it can be incompatibility

    • ***Incompatibility

  • Important to build up an effective visualization

    • A specification can be very huge


Extension for future

Extension for future

  • Complete formalization of all the comparison rules

    • Fortunately the algorithm is easily extensible

  • All the error messages are mainly syntactic

  • Addition of the semantics in order to refine messages

  • Integration with specification environment


Thank you for your attention

Thank you for your attention!

  • Géza Horváth

  • [email protected]


  • Login