12.3 Ports

12.3.1 Description

Ports are the only interfaces of actors. A port has always a protocol assigned. Service Access Points (SAP) and Service Provision Points (SPP) are specialized ports that are used to define layering.

12.3.2 Motivation

• Ports decouple interface definition (Protocols) from interface usage
• Ports decouple the logical interface from the transport

12.3.3 Notation

Class Ports

These symbols can only appear on the border of an actor class symbol.

Ports that define an external interface of the ActorClass, are defined in the Interface. Ports that define an internal interface are defined in the Structure (e.g. internal ports).

• External End Ports are defined in the Interface and the Structure
• Internal End Ports are only defined in the Structure
• Relay Ports are only defined in the Interface
• End Ports are always connected to the internal behavior of the ActorClass
• Replicated Ports can be defined with a fixed replication factor ( e.g. Port port18 [ 5 ]: ProtocolClass1 ) or a variable replication factor (e.g. Port port18[ * ]: ProtocolClass1 )

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Table 12.3: Class Port Notation

Element	Graphical Notation	Textual Notation
Class End Port		External Class End Port: Internal Class End Port:
Conjugated Class End Port		External Conjugated Class End Port: Internal Conjugated Class End Port:
Class Relay Port
Conjugated Class Relay Port
Replicated Class End Port		External Replicated Class End Port: Internal Replicated Class End Port:
Conjugated Replicated Class End Port		External Conjugated Replicated Class End Port: Internal Conjugated Replicated Class End Port:
Replicated Class Relay Port
Conjugated Replicated Class Relay Port

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Reference Ports

These symbols can only appear on the border of an ActorReference symbol. Since the type of port is defined in the ActorClass, no textual notation for the Reference Ports exists.

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Table 12.5: Title

Element	Graphical Notation	Textual Notation
Reference Port		implicit
Conjugated Reference Port		implicit
Replicated Reference Port		implicit
Conjugated Replicated
Reference Port		implicit

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