DemysIfying the Network CommunicaIon Layers · 2016. 11. 24. · DemysIfying the Network CommunicaIon Layers Steven BeleKch EDNA OperaKng Agent 6 Goal of this Session n Simplify our

Appliance&EquipmentEnergyPoliciesforaConnectedWorld14Nov2016,OCawa,Canada

DemysIfyingtheNetworkCommunicaIonLayers

StevenBeleKch

EDNAOperaKngAgent

6

GoalofthisSession

n  Simplifyourunderstanding

n  BriefoverviewofOSI“layer”modelforcommunicaKonsnetworks

n  ProvidecontextastowherecommunicaKonsprotocols“fit”

7

OSI=OpenSystemsInterconnecIonModel

n  ConceptuallayermodelforcommunicaKonsnetworks

n  Itsgoals

n  Assimpleaspossible(andnomore!)

n  Interoperabilityofdiversesystems

n  AgnosKctounderlyingstructureortechnology

8

Eachlayeronlyinteractswithadjacentlayer

Layer Example Functions Example Protocol Data U

pp

er

7. Application Send email POP3, SMTP Words on a screen! Upper layer data (incl payload)

6. Presentation Define characters ASCII

5. Session Handshaking SCP

Mid

dle

4. Transport Flow control, error detection TCP Segments

3. Network IP addressing, routing IPv6 Packets

Low

er 2. Data Link Transfer data across

physical link WiFi link layer Frames

1. Physical Electrical & physical specifications WiFi physical layer Bits

10

1. Physical Layer

2. Data Link Layer

3. Network Layer

4. Transport Layer

5. Session Layer

6. Presentation Layer

7. Application Layer

1. Physical Layer

2. Data Link Layer

3. Network Layer

4. Transport Layer

5. Session Layer

6. Presentation Layer

7. Application Layer

flow of bits

encapsulate

strip encapsulation

11

Take-HomeMessages

n  Upperlayers

n  Howdataisstructured&presented

n  Keyfocus

n Middlelayers

n  Highlytechnical,oflessconcern

n  Lowerlayers

n  HowthebitsaretransmiNed

n  Oflessconcern(?)

n  Keepinmindthisahernoon

12

Thanksto

n  BruceNordman