tarun01
Newbie level 1
sgmii spec
According to the SGMII spec, signal mapping at the MAC side
CRS is physically connected to RX_DV in the diagram. Text says "Carrier Sense (CRS) is derived/inferred from RX_DV"
This is not consistent with Clause 36.2.5.2.5, IEEE 802.3-2005
According to clause 36, CRS should remain high with receive burst of frames during carrier extension
This will lead to basic problems in CSMA/CD protocol with SGMII, CRS will not stay high during carrier extension, hence the MAC will sense the medium as idle and start frame trasnmission which could result in collision during carrier extension. The very purpose of CRS is not served.
Further, since it is a Cisco spec, I don't know whom to contact to seek clarifications.
Your help is appreciated.
According to the SGMII spec, signal mapping at the MAC side
CRS is physically connected to RX_DV in the diagram. Text says "Carrier Sense (CRS) is derived/inferred from RX_DV"
This is not consistent with Clause 36.2.5.2.5, IEEE 802.3-2005
According to clause 36, CRS should remain high with receive burst of frames during carrier extension
This will lead to basic problems in CSMA/CD protocol with SGMII, CRS will not stay high during carrier extension, hence the MAC will sense the medium as idle and start frame trasnmission which could result in collision during carrier extension. The very purpose of CRS is not served.
Further, since it is a Cisco spec, I don't know whom to contact to seek clarifications.
Your help is appreciated.
