Introduction to Ethernet para radio enlace
- 1. May 2015, ver3 Introduction to Ethernet
- 2. Proprietary and Confidential Agenda 2 • Local Area Network (LAN) • Network Devices • OSI Layers • Ethernet Frame • VLAN concept
- 3. Proprietary and Confidential The Local Area Network (LAN) 3
- 4. Proprietary and Confidential Network Devices 4 The various devices used to build a data communication network can be classified into type of equipment depending on how Ethernet packets are forwarded. HUB BRIDGE / SWITCH ROUTER
- 5. Proprietary and Confidential Functions of OSI layers 5 Physical Data Link Network Transport Session Presentation Application OSI model layers Type of communication: e-mail, file transfer, web browsing Encryption, data conversion: ASCII to EBCDIC, BCD to binary et. Starts, stops sessions. Maintains order Routes data to different LANs and WANs based on network addresses Transmits packets from node to node based on station address Electrical signals and cabling (physical medium) Ensure delivery of entire file or message
- 6. Proprietary and Confidential Protocols in OSI layers 6 Physical Data Link Network Transport Session Presentation Application OSI model layers HTTP, FTP, IRC, SSH, DNS, SNMP SSL, SFTP, IMAP, SSH, Jpeg, GIF, TIFF, MPEG, MIDI, mp3 VARIOUS API’S, SOCKETS IP, IP Sec, ICMP, IGMP Ethernet, Token Ring, SLIP, PPP, FDDI Coax, Fiber, Wireless TCP, UDP, ECN, SCTP, DCCP
- 7. Proprietary and Confidential Ethernet frame 7
- 8. Proprietary and Confidential OSI and TCP/IP model 8 Physical Data Link Layer 2,5 Network Transport Session Presentation Application Physical Data Link Layer 2,5 Network Transport Session Presentation Application Network Interface Layer 2,5 Internet Application Session Protocol Presentation Protocol Application Protocol P SFD MAC MPLS IPv4/6 TCP/UDP DATA FCS S-VLAN DATA MAC MPLS IPv4/6 TCP/UDP DATA FCS S-VLAN C-VLAN MPLS IPv4/6 TCP/UDP DATA IPv4/6 TCP/UDP DATA TCP/UDP DATA TCP/IP model OSI model layers OSI model layers E L E L 7 1 12 4 4 4 2 20/40 20/8 4 46-1500 P Preamble TCP Transmission control protocol SFD Start frame Delimiter UDP User datagram protocol MAC = Destination + Source MAC Address FCS Frame check sequence EL Ether Length/Type VLAN Virtual local area network MPLS Multiprotocol Label Switching IP Internet protocol C-VLAN Size in bytes: Transport
- 11. Proprietary and Confidential L4 11 UDP Header TCP Header
- 12. Proprietary and Confidential Inter-frame gap 12 Ethernet works in Layer 1, Layer 2 and “Layer 2,5”
- 13. VLAN concept
- 14. Proprietary and Confidential Virtual Local Area Network (VLAN) concept 14 • Imagine that you have a network and three different customer • Customer 1 • Customer 2 • Customer 3 NETWORK
- 15. Proprietary and Confidential Virtual Local Area Network (VLAN) concept 15 The most common protocol used today in configuring virtual LANs is IEEE 802.1Q VLANs are created to provide the segmentation services traditionally provided by routers in LAN configurations
- 16. Proprietary and Confidential OSI and TCP/IP model 16 Physical Data Link Layer 2,5 Network Transport Session Presentation Application Physical Data Link Layer 2,5 Network Transport Session Presentation Application Network Interface Layer 2,5 Internet Application Session Protocol Presentation Protocol Application Protocol P SFD MAC MPLS IPv4/6 TCP/UDP DATA FCS S-VLAN DATA MAC MPLS IPv4/6 TCP/UDP DATA FCS S-VLAN C-VLAN MPLS IPv4/6 TCP/UDP DATA IPv4/6 TCP/UDP DATA TCP/UDP DATA TCP/IP model OSI model layers OSI model layers E L E L 7 1 12 4 4 4 2 20/40 20/8 4 46-1500 P Preamble TCP Transmission control protocol SFD Start frame Delimiter UDP User datagram protocol MAC = Destination + Source MAC Address FCS Frame check sequence EL Ether Length/Type VLAN Virtual local area network MPLS Multiprotocol Label Switching IP Internet protocol C-VLAN Size in bytes: Transport
- 17. Proprietary and Confidential Ethernet frame 17
- 18. Proprietary and Confidential Length / Type < 1500 - Parameter indicates number of Data Bytes Length / Type > 1536 - Parameter indicates Protocol Type (PPPoE, PPPoA, ARP etc.) Preamble + SFD DA SA Length / Type DATA + PAD FCS 6 Bytes 6 Bytes 8 Bytes 2 Bytes 46 - 1500 Bytes 4 Bytes (32-bit CRC) FCS is created by the sender and recalculated by the receiver Minimum 64 Bytes < FRAME SIZE < Maximum 1518 Bytes Untagged Ethernet Frame 18
- 19. Proprietary and Confidential • Additional information is inserted • Frame size increases to 1522 Bytes 4 Bytes TPID = Tag protocol ID TCI = Tag Control Information CFI = 1 bit canonical Format Indicator Preamble + SFD DA SA Length / Type DATA + PAD FCS 3 Bit 1 Bit 12 Bit TCI CFI VLAN TAG P-TAG VLAN ID TPID = 0x8100 Tagged Ethernet Frame 19
- 20. Proprietary and Confidential VLAN ID uses 12 bits, therefore the number of maximum VLANs is 4096: • 212 = 4096 • VID 0 = reserved • VID 4090-4096 = reserved (dedicated for IP-10’s internal purposes such as MNG etc.) • VID 1 = default • After tagging a frame, FCS is recalculated • CFI is set to 0 for ETH frames, 1 for Token Ring to allow TR frames over ETH backbones (some vendors may use CFI for internal purposes) Tagging a Frame 20
- 21. Proprietary and Confidential TPID / ETHER-Type / Protocol Type… 21 TPID in tagged frames in always set to 0x8100 It is important that you understand the meaning and usage of this parameter Protocol type Value Tagged Frame 0x8100 ARP 0x0806 Q-in-Q (CISCO) 0x8100 Q-in-Q (other vendors) 0x88A8 Q-in-Q (other vendors) 0x9100 Q-in-Q (other vendors) 0x9200 RARP 0x8035 IP 0x0800 IPv6 0x86DD PPPoE 0x8863/0x8864 MPLS 0x8847/0x8848 IS-IS 0x8000 LACP 0x8809 802.1x 0x888E
- 22. Proprietary and Confidential • Additional VLAN (S-VLAN) is inserted • Frame size increases to 1526 Bytes Q-in-Q 4 Bytes Preamble + SFD DA SA Length / Type DATA + PAD FCS 3 Bit 1 Bit 12 Bit CFI S - VLAN TPID = 0x88A8 P-TAG VLAN ID TCI CFI P-TAG VLAN ID TCI TPID = 0x8100 C - VLAN 4 Bytes 3 Bit 1 Bit 12 Bit 22
- 23. Thank you 23