PLC 技術培訓班(第7講)ppt課件

1、 以太網- 根底訪問. To IEEE 802.3 和 IEEE 802.3ISO/OSI 通訊方式每一種通訊處置分隔為邏輯部件 ，經過一定的接口銜接起來1 物理層7 運用層6 表達層5 會話層4 傳輸層3 網絡層2 數據鏈路層訪問總線媒質 報文的發(fā)送和接納面向運用層面向傳輸層器件運用效力電信號的普通闡明信息格式化和編碼通訊的同步和控制器件、段、消除缺點之間的銜接數據打包和經過網絡選擇路由網絡部件7 Application layer6 Presentation layer5 Session layer4 Transport layer3 Network layer2 Data link la

2、yer7 Application layer6 Presentation layer5 Session layer4 Transport layer3 Network layer2 Data link layer路由器集線器, 交換機,橋1 Physical layer1 Physical layer網關Device ADevice B中繼器根底闡明雙絞線對100 BaseTX - 100 Mb/s 5類線: UTP or STP (非屏蔽 /屏蔽 雙絞線對) 最大段長度為 100m RJ-45 插頭 星形拓樸構造半雙工方式 數據傳輸在同一時間只能在一個方向進展 舉例，步話機1半雙工和全雙工P

3、CTransmitReceivePCTX+RX+RX-TransmitReceiveTX+TX-RX+RX-TX-1001010半雙工和全雙工全雙工方式 數據傳輸同時在兩個方向進展 舉例，TransmitReceiveTransmitReceive集線器/交換機PCTX+RX+RX-TX+TX-RX+RX-TransmitReceivePCTX+TX-RX+RX-RX+RX-TX+TX-TX-01011001防止碰撞CSMA/CD 相對于 Full DuplexCarrier Sense Multiple Access with Collision Detection (CSMA/CD) 載波

4、偵聽、多路訪問/碰撞檢測 Standard-Ethernet-Communication: Collisions possibleCarrier SenseMultiple Access/Collision DetectionCSMA/CD 相對于 Full Duplex Full Duplex: 發(fā)送和接納同時進展 Switches: 協(xié)調數據傳輸SwitchSwitchSwitchStandard-PROFINET-Communication: no collisions possible某些規(guī)定自動-交錯-轉換交錯-轉換-電纜1236TransmitReceive1236Transmit

5、ReceiveSwitchSwitchAuto-Cross-Over1:1-電纜1236TransmitReceive1236TransmitReceiveSwitch within a Field deviceSwitch PROFINET-建議在交換機之間和交換機與器件之間運用 1:1 電纜。自動-轉換Hub or switch現有的 10 Mb/s 網絡新的 100 Mb/s 網絡帶自動轉換的交換機Cut through, Store and Forward快捷方法，儲存和發(fā)送The Cut-Through method forwards the frame without checki

6、ng it. 快捷方法，向前發(fā)送的楨不進展數據效驗。Store and Forward first checks the received data before forwarding them. 接納到的楨先儲存,在繼續(xù)發(fā)送之前進展數據效驗。集線器與交換機的比較一個交換機指定數據接納的方向在站之間只需指定的通訊路由被運用 降低網絡負載不會呵斥數據碰撞共享 LAN局域網集線器傳送數據到一切的站每一次數據交換對整個網絡 高網絡負載有能夠呵斥數據碰撞集線器交換機交換機LAN局域網在一個網絡段內尋址網絡成員 運用 MAC-地址MAC 地址IP地址計算機需求一個地址用來發(fā)送和接納數據包或數據楨尋址每一

7、個網絡適配器 有一個獨一的物理地址 ，這一地址由制造商確定是一個6字節(jié)地址 ， 即 88-A0-26-E8-84-01網絡適配器MAC網絡訪問互聯(lián)網傳輸層運用層 Ethernet-地址, OUIThe Ethernet-Address (Organizationally Unique Identifier (OUI), MAC-Address, Physical Address) is a 6 Byte-Address in Hex-Format e. g. 00-0E-CF-12-34-56The PNO may supply users with the manufacturer spec

8、ific part 00-0E-CF (16 777 214 devices possible). x x x x x x 47 46 40 39 32 31 24 23 16 15 8 7 0 = 0, Individual address= 1, group address= 0, global address= 1, local address0 EC F0 0Manufacturer specific part (OUI) consecutive number制造商指定部分 延續(xù)號A deeper look into the Ethernet Frame以太網報文楨分析a) Ether

9、net II DIX Frameb) IEEE 802.3 FrameVLAN-Tag (VLAN ID)acc IEEE 802.1QPreambleSFDDestinationAddressSourceAddressLengthor TypeData unitCRCCheck56 bits848 bits48 bits16 bits46 -1500 bytes32 bitsPreambleSFDDestinationAddressSourceAddressLengthData unitCRCCheck56 bits848 bits48 bits16 bits46 -1500 bytes32

10、 bitsSwitches交換機 Associates each port with physical addresses connected through it每一個端口與銜接它的物理地址相關 Sends frame out the port associated with the physical address發(fā)送楨與其物理地址相關的端口輸出 Improves the performance of the network改善網絡性能 Two most common types兩種通訊類型Cut-through (10 . 3 s passing through time)快捷方式Sto

11、re and forward ( 11 . ?)儲存再發(fā)送方式The Function of Switches交換機功能ABCDSimultaneously同時進展47-2C-36-64-00-0055-E0-08-33-4E-3991-09-83-5B-03-0914-45-08-7A-11-16A to CB to DAddressing of network participants in different networks 對不同網絡之間網絡成員的尋址 using IP-Addresses運用IP地址IP-Routing IP 路由FramesNetwork ENetwork CNe

12、twork BNetwork DNetwork ARoutersLANNetwork or Internet?!Internet Protocol (IP)Each Network Adapter also has an IP address 每一個網絡適配器還有一個IP地址Consists of a 32-bit binary addressIP地址是32位二進制地址Hardware-independent system allows a computer to deliver data on a more complex routed networkIP地址與硬件無關，只是網絡路由中一個計

13、算機向更多其它計算機傳送數據時需求Physical Address vs. IP Address物理地址與IP地址比較There are 2566 or 2.81 x 1014 different MAC addressesMAC物理地址由6字節(jié)16進制格式表示There are 2564 or over 4 billion40億 different IP addressesIP地址由4字節(jié)10進制格式表示 Correspondence table relates your IP address to your MAC address IP地址對MAC地址有相應的列表關系IP Address

14、32-bit binary address for example 6 Divided into four 8-bit segments called octets.分成4個8位段 Expressed in a dotted decimal format.以小數點格式表示 Segments are whole numbers between 0 and 255.每一段的表 示范圍從0到255 Part of the IP address is used for Network ID.IP地址的一部分 用作網絡表識and part of the address is for Host ID. I

15、P地址的一部分用作上位機的ID表識Most address fall into 3 separate classes. 大多數IP地址分屬以下三種類型Class A, Class B, Class CEncapsulation of the protocols協(xié)議包裝 The application data are embedded in the data area of a TCP/IP packet 運用數據嵌入TCP/IP數據包的數據區(qū)內 Every TCP/IP packet is part of the data area of an Ethernet packet 每個TCP/I

16、P數據包是以太網數據區(qū)的一部分Ethernet header(Ethernet addresses)Ethernet data area以太網數據區(qū)Ethernet trailer(FCS)Application data運用數據IP header(IP addresses)TCP header(port numbers)TCP data areaTCP數據區(qū)IP data areaIP數據區(qū)Two Parts of IP Addresses IP地址分為兩部分Net ID : Network Address 網絡標識：網絡地址All Hosts within a network have t

17、he same Net IDNet IDs are unique and are assigned by a naming authorityHost ID : Host Address 主機標識：主機地址Each Host within a network has a unique Host IDHost ID is assigned by the respective administratorNet IDHost ID031Net ID and Host ID AllocationClassRangeNetworksHostA0 7-bit network24-bit host1-126

18、12616777216B1 014-bit network16-bit host128-1911638465536C1 1 021-bit network8-bit host192-2232097152256The Subnet Mask子網屏蔽Net IDHost IDSubnet Mask3111111111111111111111111100000000Subnet IDNet IDHost ID0Net ID and Host ID AllocationExample: Class C networkIP address: 192.157.018.032Class C NetworkH

19、ost PortionDecimal 192 . 157. 018.032Binary 11000000.10011101.00010010.00100000Subnet mask 11111111.11111111.11111111.00000000Spezielle IP-Adressklassen 特殊IP地址類型1 1 1 0Multicast Group ID 28 bits 組28位ID作為廣播0314Klasse D 224.x.x.x 551 1 1 1Reserviert fr knftige Erweiterungen 28 bits0314Klasse E 240.x.x

20、.x 55IP Header IP頭報文VersionTOSIdentificationTotal LengthFlagsProtocolSource IP AddressDestination IP AddressIP Options (optional)PaddingData32 bitsIHLFragment OffsetTime to LiveHeader Checksum048162431ARP and RARP Address Resolution Protocol (ARP)Identifies the MAC address associated with an IP addr

21、essUses an ARP table or ARP cache Reverse Address Resolution Protocol (RARP)Identifies the IP address associated with a MAC addressboot PROM/BOOTPAddressing in the networkThe Ethernet address (MAC address) Worldwide unambiguous physical device address 全世界明確的物理器件地址Vendor code and consecutive number 制

22、造商號和延續(xù)號6-byte value (6 hexadecimal numbers)e.g. C0-10-A4-00-17-ACThe Internet address (IP address)Network unambiguous addressNetwork component (network ID) and user component (host ID)32-bit value (4 decimal numbers)e.g. Subnetwork142.0.1Subnetwork142.0.2Total network142.0.The Subnet maskMasking out

23、 of IP address in thenetwork ID and host ID components 32-bit value, e.g. RouterDHCP/DNS動態(tài)主機組態(tài)協(xié)議/ Host Configuration and Name Resolution主機組態(tài)和名字分解DHCP (Dynamic Host Configuration Protocol)For automatical adjustment of TCP/IP configuration data.A DHCP-Server is able to parameterize a Client with an IP

24、-address and subnet maskName Resolution PC Nr. A PC Nr. B8 PC Nr. C Hosts FileDATAHost: PC Nr. AIP: Host: PC Nr. BIP: PC Nr. CIP: 8PC Nr. B ?Assigning a name to an IP-addressSafe Data Transmission using TCP Flow controlEncapsulation of the protocols The application data are embedded in the data area

25、 of a TCP/IP packet Every TCP/IP packet is part of the data area of an Ethernet packetEthernet header(Ethernet addresses)Ethernet data areaEthernet trailer(FCS)Application dataIP header(IP addresses)TCP header(port numbers)TCP data areaIP data area通訊協(xié)議總結運用層Application layerTCP傳輸層Transport layerUDPCo

26、nnection-orientedFTPSMTPDCOMIP互聯(lián)網層InternetlayerEthernet網絡層Network layerConnection-freeSNMPTFTPNFSARPThe TCP/IP Protocol SuiteIP: Internet Protocol互聯(lián)網協(xié)議Protocol which carries out connection-free transportation of datagrams in the local subnetwork, or which passes them on to further subnetworksTCP: Tr

27、ansmission Control Protocol 傳輸控制協(xié)議Transport protocol for connection-oriented, secure and sequence-based communication between stationsUDP: User Datagram Protocol 用戶數據包協(xié)議Transport protocol for connection-free communication between stationsIn contrast to TCP, UDP is not secure. UDP does not provide an

28、y guarantee for correct transmission of dataARP: Address Resolution Protocol 地址分解協(xié)議Protocol which determines the associated MAC addressed for every logical Internet address definedThe TCP/IP ApplicationsSMTP 簡化郵件發(fā)送協(xié)議Simple Mail Transfer Protocol used for 超級文本傳送協(xié)議Hypertext Transfer Protocol used for

29、WWW browserFTP 文件傳送協(xié)議File Transfer Protocol used for transportation of files between computersDCOM 分布式部件目的方式Distributed Component Object Modelpermits the distribution of COM objects in a networkSNMP簡易網絡管理協(xié)議Simple Network Management Protocolused for central management of network componentsOthers DHCP

30、, TFTP, TELNET, SOAP, Microsoft .NETTransmission Control ProtocolTCP is responsible for the secure data transmission establishes a connection between 2 network partners follows the client / server principle acknowledges a data frame by sending an ack-number within the next frame secures the data wit

31、h a checksum and a sequence number addresses an application via a so called port number (source port number, destination port number)TCP Data FormatSource PortDestination PortSequence NumberAcknowledgment NumberDOReservedACKURGPSHRSTSYNFINWindowChecksumUrgent PointerOptionsPaddingData (length varies

32、)32 bitsTCP/IP FramePreambleSFDDestinationAddressSourceAddressLengthor TypeDataFrameCheckSequence56 bits848 bits48 bits16 bits46 -1500 bytes32 bitsVersionTOSIdentificationTotal LengthFlagsProtocolSource IP AddressDestination IP AddressIP Options (optional)PaddingDataIHLFragment OffsetTime to LiveHeader Checksum048162431Source PortDestination PortSequence NumberAcknowledgment N