100GE以太网技术介绍
The 802.3ba task force’s guidelines include leaving the majority of 802.3 standards in place.
Figure 4. 40/100 Gbps Ethernet Architecture
No changes will be made to the medium access control (MAC) layer beyond increasing the data rates to 40 and 100 Gbps. This means that other characteristics, including frame format, mini-mum/maximum frame sizes, and full-duplex only operation remain the same.
The reconciliation sublayer (RS) maps the MAC’s serial bitstream into its respective 40 and 100 Gbps media independent interfaces. These interfaces are being developed based on the earlier XGMII (10 Gbps) interface: CGMII (100 Gbps) and XLGMII (40 Gbps). These interfaces in the architecture along with the components that use these interfaces are being standardized through multiple multi-source agreements (MSAs) between industry component vendors , such as the CFP MSA (see the transceiver section below).
The remaining sublayers serve to serialize the data received through the MII and present it to the copper or optical medium. The physical coding sublayer (PCS) provides coding, including scram-bling and control block encoding. 64/66b coding, as used in 10GBASE-R, is the choice for these higher speeds. The optional FEC sublayer performs encoding for forward error correction. The physical medium attachment (PMA) sublayer serializes the coded data as required by the medium. The physical medium dependent (PMD) sublayer is responsible for signaling of the serial stream to the medium through the media dependent interface (MDI).
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