Remote Fault Indication And Far End Fault Indication; Cana - Nortel 8600 Configuration Manual

16 Ethernet module fundamentals

Remote Fault Indication and Far End Fault Indication

The 802.3z Gigabit Ethernet standard defines Remote Fault Indication
(RFI) as part of the autonegotiation function. RFI provides a way for
stations on both ends of a fiber pair to be informed if a problem occurs
with a fiber. Because RFI is part of the autonegotiation function, if you
disable autonegotiation, RFI is automatically disabled. Therefore, Nortel
recommends that you enable autonegotiation on Gigabit Ethernet links
in all cases where autonegotiation supports the devices on both ends of
a fiber link.
For 10 Gigabit Ethernet, Far End Fault Indication (FEFI) is automatically
used. Remote failure is detected at the MAC level. Upon receiving FEFI
notification from the remote site, the 10 Gbit/s LAN module port changes
the link state to nonoperational.
The WAN PHY module supports FEFI. When one end of a 10 Gbit/s WAN
module link detects a link-down condition or is administratively disabled,
the Synchronous Optical Network (SONET) Alarm Indication Signal (AIS)
notifies the other end of the link. Upon receiving this notification, the other
end changes its link state to down.

CANA

The 10/100/1000 Mbit/s ports of R and RS modules support Custom
Auto-Negotiation Advertisement (CANA). Use CANA to control the speed
and duplex settings that these modules advertise during autonegotiation
sessions between Ethernet devices. You can establish links only using
these advertised settings, rather than at the highest common supported
operating mode and data rate.
Use CANA to provide smooth migration from 10/100 Mbit/s to 1000 Mbit/s
on host and server connections. Using autonegotiation, the switch always
uses the fastest possible data rates. In scenarios where uplink bandwidth
is limited, CANA provides control over negotiated access speeds, and thus
improves control over traffic load patterns.
Only 10/100/1000 Mbit/s RJ-45 ports support CANA. To use CANA, you
must enable autonegotiation.
ATTENTION
If a port belongs to an MLT group and CANA is configured on the port (an
advertisement other than the default is configured), then you must apply the
same configuration to all other ports of the MLT group (if they support CANA).
If a 10/100/1000 Mbit/s port that supports CANA is in an MLT group with
10/100Base-TX ports, or other port type that does not support CANA, then you
can use CANA only if it does not conflict with MLT abilities.
Nortel Ethernet Routing Switch 8600
Configuration — Ethernet Modules
NN46205-503 04.01 21 December 2009
Copyright © 2008-2009 Nortel Networks. All Rights Reserved.