USGMII:
USGMII supports eight 10M/100M/1G network ports over 10Gbps SERDES between MAC and PHY, 主要用于通过一条10G lane连接8口的GE phy
USXGMII:
USXGMII-Single Port version can be used to support ONE network port with 10M/100M/1G/2.5G/5G/10G data rates, 主要用于通过一条10G lane连接1个10G PHY
SGMII
SGMII supports a single 10M/100M/1G network port over 1,25Gbps SERDES between MAC and PHY
QSGMII
QSGMII supports four 10M/100M/1G network ports over 5Gbps SERDES between MAC and PHY
XFI
一种老的 10G接口，用于连接MAC和PHY, 1个lane, 常用于外接XFI光模块，phy侧因要有CDR电路，XFP模块尺寸比较大，功耗也比较大。XFI接口的电气特性定义在INF-8077文档
SFI
一种10G接口，用于连接MAC和PHY, 1个lane, 常用于外接SFI光模块，和XFI相比，phy侧不需要有CDR电路，SFP模块尺寸比较小，功耗也比较小。SFI接口的电气特性定义在SFF8431文档
10Gbase-R
主要应用于前面板，或板内连接。
10GBASE-R is a specific physical layer implementation of the 10 Gigabit Ethernet link defined in clause 49 of the IEEE 802.3-2008 specification
10 Gbps data rate at the XGMII interface and a 10.3125 Gbps serial line rate with 64B/66B encoding.
10Gbase-KR
主要应用于背板连接。
The IEEE 802.3ap-2007 specification also requires each backplane link to support multi-data rates of 1Gbps and 10 Gbps speeds.
10GBASE-KR implementation uses the XGMII interface to connect to the reconciliation sublayer (RS) with 64B/66B PCS encoding, the optional Forward Error Correction (FEC), and Auto-Negotiation (AN) support to the Highest Common Denominator (HCD) technology with the partner link. The optional FEC, LT, and AN logic is implemented in the core fabric
