CIS 725

Service Specification

Transport Layer

• Connection management• End-to-end control

Network layer

Transport layer

Application FA

Mutual exclusion

• Request• Enter• Release

Interface

• Creq (Connection Request)• Cind (Connection Indication)• Cres (Connection response)• Cconf (Connection confirm)• Dreq (Disconnection request)• Dind (disconnection indication)

Interface

• Creq (Connection Request)• Cind (Connection Indication)• Cres (Connection response)• Cconf (Connection confirm)• Dreq (Disconnection request)• Dind (disconnection indication)• Dres (Disconnection response)• Dconf (disconnection confirm)

1

2

3

4

Creq1Cconf1Dreq1

Cind2Cres2Dind2

?Creq1

!Cind2

?Cres2

5

!Cconf1

6 7?Dreq1 !Dind2

6?Dreq1

7!Dind2

!Cind2

?Dreq1

?Dreq1

7!Dind2

7!Dind2

?Cres2

!cind2

?creq1

?cres2

!cconf1

?creq2

!cind1

?cres1

!cconf2

?creq1

?creq1

?creq2

?creq2

!cind2

?creq1

?cres2

!cconf1

?creq2

!cind1

?cres1

!cconf2

?creq1

?creq1

?creq2?creq2

!cind2

Transmission Control Protocol

• End-to-end transport protocol• End point (IP address, port)

TCP connection establishment

CIS 725

Lecture 16