Remote Fault Detection - Avaya P550R User Manual Addendum

User Guide Addendum for the Avaya P550R and P880, v5.3.2
Remote Fault
Detection
6
is automatically set to 64. Depending on the number of
VLANs that are created, you may need to manually
change this hash table setting. For information on the
relationship between hash table sizes and the number of
VLANs that are configured on the switch, see
"Relationship between VLANs, AFT, and Hash Table
Sizes," in Chapter 6, "Managing the Address Forwarding
Table."
The following information will be added to "Configuring Physical
Port Parameters on Gigabit Ports" in Chapter 5, "Configuring Port
Parameters."
Remote fault detection is a proprietary feature that prevents a loss of
traffic if a physical or signaling error occurs on a switch-to-switch
fiber link.
A remote fault is an error that one switch can detect but the other
switch cannot. For example, if a transmit fiber breaks, the remote
port continues to receive data and so detects that the link is good.
However, the remote port cannot detect that the data it transmits is
not received by the local port.
If remote fault detection is enabled and a remote fault occurs, the
local switch sends a message to inform the remote switch of the
fault. The remote switch then shuts down the remote port.
If the receive signal is restored on the local port, the local port sends
a message to the remote switch, which then turns on the remote
port again.
* Important: Remote fault detection must be enabled on both the
local port and remote port for the feature to work.
For example, in Figure 1:
1. Port 1 on Switch A is not receiving traffic from Port 2 on
Switch B.
This problem could occur because:
The transmitter on port 2 is not functioning.
—
The receiver on port 1 is not functioning.
—
The fiber is broken or disconnected.
—
January 7, 2003 Part No. 610-0229-091