RE: Link Status Signaling Clarification
When a fault condition is detected, the LF sequence ordered set is
transmitted on the side that detected the fault condition.
For instance, if a PCS can't achieve sync to the received signal, it will
send the LF sequence ordered set on the XGMII. The local RS will receive the
LF and know there is a fault. Receipt of the LF will cause the local RS to
send RF. The RS at the remote end will receive the RF (assuming there is
only a fault in one direction) and know that there is a fault.
If a PHY XGXS can't achieve sync to the XAUI signal, then it will send LF
sequence ordered sets to the PMA. The remote RS will receive the LF and know
that there is a fault. It will therefore send RF which will let the local RS
know that there is a fault.
There is no local fault message sent to the RS. The only communication
between Phy sublayers and the RS is the data stream. There are bits set in
MDIO registers which can be probed by the local management agent to get more
information about where the fault is being detected and the nature of the
From: Rogers, Shawn [mailto:s-rogers@xxxxxx]
Sent: Friday, April 06, 2001 6:13 AM
To: 'Taborek, Rich'
Cc: 802.3ae; Chan, Roger
Subject: Link Status Signaling Clarification
Rich, need clarification on the following:
"..The purpose of link status reporting is to quickly identify and convey
link status conditions to the RS which can take the necessary action..."
"Link status signaling follows the detection or recognition of a link
status condition and involves the generation of Sequence ordered-sets by the
PCS transmit process."
I interpret this to mean:
When the 10GBASE-X PCS detects a fault condition, it sends the local fault
message to the RS and the transmits the LF Sequence ordered set to the PMA.