Alcatel-Lucent 7750 SR OS Configuration Manual page 35

Table 3: BFD Control Packet Field Descriptions (Continued)
Field
D Bit
P Bit
F Bit
Rsvd
Detect Mult
Length
My Discriminator
Your Discriminator
Desired Min TX Interval
Required Min RX
Interval
Required Min Echo RX
Interval
7750 SR OS Router Configuration Guide
The "demand mode" bit. If set, the transmitting system wishes to operate in demand
mode.
The poll bit. If set, the transmitting system is requesting verification of
connectivity, or of a parameter change.
The final bit. If set, the transmitting system is responding to a received BFD control
packet that had the poll (P) bit set.
Reserved bits. These bits must be zero on transmit and ignored on receipt.
Detect time multiplier. The negotiated transmit interval, multiplied by this value,
provides the detection time for the transmitting system in asynchronous mode.
Like the IGP hello protocol mechanisms, this is analogous to the hello-multiplier in
IS-IS, which can be used to determine the hold-timer.
(hello-interval) x (hello-multiplier) = hold-timer. If a hello is not received within
the hold-timer, a failure has occurred.
Similarly in BFD: (transmit interval) x (detect multiplier) = detect-timer. If a BFD
control packet is not received from the remote system within detect-timer, a failure
has occurred.
Length of the BFD control packet, in bytes.
A unique, nonzero discriminator value generated by the transmitting system, used
to demultiplex multiple BFD sessions between the same pair of systems.
The discriminator received from the corresponding remote system. This field
reflects back the received value of my discriminator, or is zero if that value is
unknown.
This is the minimum interval, in microseconds, that the local system would like to
use when transmitting BFD control packets.
This is the minimum interval, in microseconds, between received BFD control
packets that this system is capable of supporting.
This is the minimum interval, in microseconds, between received BFD echo
packets that this system is capable of supporting. If this value is zero, the
transmitting system does not support the receipt of BFD echo packets.
IP Router Configuration
Description
Page 35