LanMan_C05_以太网.ppt

* Length/Type field This two-octet field takes one of two meanings, depending on its numeric value. If the value of this field is less than or equal to 1500 decimal (05DC hexadecimal), then the Length/Type field indicates the number of MAC client data octets contained in the subsequent MAC Client Data field of the basic frame (Length interpretation). If the value of this field is greater than or equal to 1536 decimal ( 0600 hexadecimal), then the Length/Type field indicates the nature of the MAC client protocol (Type interpretation). The Length and Type interpretations of this field are mutually exclusive. When used as a Type field, it is the responsibility of the MAC client to ensure that the MAC client operates properly when the MAC sublayer pads the supplied MAC client data, as discussed in 3.2.7. LanMan 2016 YKW UESTC 5.8.3 千兆位以太网 千兆位以太网PHY标准 802.3z - 1998 1000BASE-X 1000BASE – LX/SX/CX 802.3ab - 1999 1000BASE-T 标准特点 保持以太网的传统帧格式，可选jumbo帧 通常使用全双工运行，但还保留了半双工模式 1000BASE-CX：并不实用 LanMan 2016 YKW UESTC 5.8.3 千兆位以太网 1000BASE-LX：长波、8B/10B 1310nm@OS1/5km LD/FP 1000BASE-SX：短波、8B/10B 850nm@OM2/500m VCSEL 1000BASE-CX 平衡型屏蔽电缆 ~ 25m 8B/10B 1000BASE-T UTP5e 100m 4D-PAM5 注意：IEEE 802标准中从未定义UTP6的使用 1000BASE-TX使用UTP6，标准为TIA 854但无产品 LanMan 2016 YKW UESTC 5.8.4 万兆位以太网 万兆位以太网PHY标准 IEEE 802.3ae – 2002 10GBASE - LX4：1300nm@OMI/OM2，300m 10GBASE - SR/LR/ER：园区网 10GBASE - SW/LW/EW：广域网 IEEE 802.3ak-2004：10GBASE - CX4 IEEE 802.3aq-2006：10GBASE-LRM LRM：1300nm，64B/66B，0M1/OM2，220m IEEE 802.3an-2006：10GBASE-T 10GbE体系：只支持全双工链路！ LanMan 2016 YKW UESTC 5.8.4 万兆位以太网 10GbE体系图 Logical Link Control (LLC) “Ethernet” Upper Layers Media Access Control (MAC) Serial WAN PHY (64B/66B + WIS) Serial PMD 850 nm WWDM LAN PHY (8B/10B) Serial LAN PHY (64B/66B) XGMII XGMII Serial PMD 1310 nm Serial PMD 1550 nm WWDM PMD 1310 nm Serial PMD 850 nm Serial PMD 1310 nm Serial PMD 1550 nm XGMII LX4 SR LR ER SW LW EW LanMan 2016 YKW UESTC 5.8.4 万兆位以太网 10GbE接口命名规则：三前缀 光收发类型 S：短波长、850nm、VCSEL L：长波长、1310nm、LD/FP E：超长波