target = "https://www.rfc-editor.org/rfc/rfc8899#section-5.1.1"

# 5.1.1.  Timers
#
# The method utilizes up to three timers:
# 
# PROBE_TIMER:  The PROBE_TIMER is configured to expire after a period
#    longer than the maximum time to receive an acknowledgment to a
#    probe packet.  This value MUST NOT be smaller than 1 second and
#    SHOULD be larger than 15 seconds.  Guidance on the selection of
#    the timer value is provided in Section 3.1.1 of the UDP Usage
#    Guidelines [BCP145].
# 
# PMTU_RAISE_TIMER:  The PMTU_RAISE_TIMER is configured to the period a
#    sender will continue to use the current PLPMTU, after which it
#    reenters the Search Phase.  This timer has a period of 600
#    seconds, as recommended by PLPMTUD [RFC4821].
# 
#    DPLPMTUD MAY inhibit sending probe packets when no application
#    data has been sent since the previous probe packet.  A PL
#    preferring to use an up-to-date PMTU once user data is sent again
#    can choose to continue PMTU discovery for each path.  However,
#    this will result in sending additional packets.
# 
# CONFIRMATION_TIMER:  When an acknowledged PL is used, this timer MUST
#    NOT be used.  For other PLs, the CONFIRMATION_TIMER is configured
#    to the period a PL sender waits before confirming the current
#    PLPMTU is still supported.  This is less than the PMTU_RAISE_TIMER
#    and used to decrease the PLPMTU (e.g., when a black hole is
#    encountered).  Confirmation needs to be frequent enough when data
#    is flowing that the sending PL does not black hole extensive
#    amounts of traffic.  Guidance on selection of the timer value are
#    provided in Section 3.1.1 of the UDP Usage Guidelines [BCP145].
# 
#    DPLPMTUD MAY inhibit sending probe packets when no application
#    data has been sent since the previous probe packet.  A PL
#    preferring to use an up-to-date PMTU once user data is sent again,
#    can choose to continue PMTU discovery for each path.  However,
#    this could result in sending additional packets.
# 
# DPLPMTUD specifies various timers; however, an implementation could
# choose to realize these timer functions using a single timer.

[[spec]]
level = "MUST"
quote = '''
This value MUST NOT be smaller than 1 second and
SHOULD be larger than 15 seconds.
'''

[[spec]]
level = "MAY"
quote = '''
DPLPMTUD MAY inhibit sending probe packets when no application
data has been sent since the previous probe packet.
'''

[[spec]]
level = "MUST"
quote = '''
CONFIRMATION_TIMER:  When an acknowledged PL is used, this timer MUST
NOT be used.
'''

[[spec]]
level = "MAY"
quote = '''
DPLPMTUD MAY inhibit sending probe packets when no application
data has been sent since the previous probe packet.
'''