Protocol Design Phase

PROTOCOL DESIGN PHASE Protocol

Layer Protocol Entities Layered Protocol Design Protocol Structuring Protocol Element Protocol Data Unit Specification Language

PROTOCOL LAYER 

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The Functional requirement of the system are defined in the required service specification Specification define the observable behaviour of a system as it can experienced by the service users at the service access point (SAPs) A Service corresponds to the shared boundary between system and its environtment Service provider is the system supports the required service

PROTOCOL LAYER (con’t.) 

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The service behaviour defines the common behaviour of the service provider and its environment in terms of the permissible interaction [Service priimitives] The Service is defined by abstracting from all possible internal structures that can be given to the service provider. Protocol design phase takes the services specification that result from the service design phase as input

PROTOCOL LAYER (con’t.)  Struktur

internal dari service provider secara sistematis didefinisikan selama fase desain protokol.  Struktur internal terdiri dari set of distributed and cooperated part (protocol entities) dan lower level service (LLS) provider

PROTOCOL LAYER (con’t.)  Problem

: How the gap between the required service and LLS is bridged, khususnya kalau gap itu hanya bisa di-bridged by of protokol yang sangat komplek??  Solution: Dekomposisi original service ke more simple protocol dan intermediate level service

PROTOCOL LAYER (con’t.)  1.

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Langkah penyelesaian: Rancang Protokol yang menyediakan original required service dan digunakan untuk intermediate service Rancang protokol yang menyediakan intermediate service dan digunakan sebagai original LLS Starting from the required service one can introduce a layered structure, where LLS provider and a protocol layer are defined

PROTOCOL ENTITIES  Internal

structure of protocol layer consist of part yang disebut protocol entities, yang pendefinisiannya mengikuti ditributed nature dari required service dan LLS  Protocol entities cooperate through the LLS provider in order to provide the required service.

PROTOCOL ENTITIES (cont’d.) 

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Protokol mendefine behaviour protocol entities dalam hal : Service primitives performed at the SAPs of the required service Service primitives performed at the SAPs of the LLS The relationship between the primitives

PROTOCOL ENTITIES (cont’d.) 

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Sehingga behaviour protocol entities mendefine how these entities cooperate through the LLS dan how they provide the required service by cooperating A Protocol bridges the gap between the required service and the LLS, by defining the rules for cooperation between protocol entities and way these protocol entities use the LLS to cooperate (Definisi berikutnya)

LAYERED PROTOCOL DESIGN  Decomposition

strategy pada struktur protokol yang terdiri dari protocol entities dan LLS provider digunakan unt provide service bisa digunakan secara iteratif pada level abstraksi sesudahnya, seperti protocol stack  N-protocol structure consist of N-protocol entities dan (N-1)-service (LLS) provider

LAYERED PROTOCOL DESIGN (cont’d)  (N-1)

service seterusnya terdiri dari (N-1) protocol entities dan sebuah (N-2)-service (LLS) provider.  The proccess can be repeated until LLS provider is obtained that can be directly realized by component that provide LLS sebelumnya.  Proses dekomposisi ini akan membentuk struktur protokol

PROTOCOL ELEMENTS  Protocol

elements are the functional building block that can be used to define a protocol  Kompleksitas sebuah protokol ditentukan oleh banyaknya elemen protokol dan ketergantungan diantaranya sekaligus intertwining nya

PROTOCOL ELEMENTS (cont’d)  Each

protocol element may support:  One or more service element of the required service  The cooperation between protocol entities  Or a combination

PROTOCOL DATA UNIT  Are

units of information that can be exchange between protocol entities through the LLS  Information contained in PDUs must support the essensial purpose of the service and the remote cooperation of protocol entities to provide the service

PROTOCOL DATA UNIT(cont’d) Klasifikasi infromasi yang dilewatkan: 1. User data, which is information transparency exchanged between service users 2. Protocol data Information (PCI), which is information exchanged between protocol entities in order to allow them to coordinate their operation

SPECIFICATION LANGUAGE A

Spec Lang serves the purpose of representing design concept  Design concepts are abstractions of aspect of technical object of concern  In service and protocol design, generic design concept are service, service primitive, SAP, protocol entities

ARCHITECTURAL SEMANTIC  Specification

is representasi dari design menggunakan bahasa spesifikasi  This representation is used in the design process as a vehicle for analysis, comm between designers, and manipulation  A design Model is set of design concept and composition operator that it possible to combine design concept

ARCHITECTURAL SEMANTIC (cont’d) A

specification language can be seen as a set of language construct that can be used to produce a specification  Desing Model Represented by Spec language  Spec lang interpreted as Design model  Design represented by spec

ARCHITECTURAL SEMANTIC (cont’d)  Is

The relationship between the design concept and composition operator of a desig model, and their possible representation in spec language

PROTOCOL SPECIFICATION LANGUAGES Unambiguos, clear and concise specification  A foundation for the functional analysis of specificatiob  A basis for the verification of specification  A basis for the development of implementation from a specification Standar : LOTOS (Language of Temporal Ordering Spec ==ISO FDTs) SDL (Specification and Description Language = CCIT FDT) 

Implementation Realtion (Correctness formula) (hide

G in (PE1|||PE2)|[G]|LLS) imp RS Model RS merpk behaviour required service Model LLS merp behaviour dari LLS Set gate Model G merpk set SAPs dari LLS Model PE1 dan PE2 merpk behaviour prot ent Komposisi dari PE1, PE2 dan LLS sebagai SAPs of LLS tdk diekspos ke servise user should yield a behaviour that implemented by required service RS

PERFORMABILITY(Performansi dan Reliabilitas) 

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Diexpresikan dengan Parameter QoS (Quality of Service): Maximum Transit Delay : Jumlah maks waktu yang diijinkan mengirimkan message from a service to another Minimum Throughput : jumlah minimum dari traffic; data unit/time; yang bisa didukung oleh SP Residual Error rate : the probability that transmitted data is lost or arrives corrupted