target = "https://www.rfc-editor.org/rfc/rfc8899#section-5"

# 5.  Datagram Packetization Layer PMTUD
#
# This section specifies Datagram PLPMTUD (DPLPMTUD).  The method can
# be introduced at various points (as indicated with * in Figure 2) in
# the IP protocol stack to discover the PLPMTU so that an application
# can utilize an appropriate MPS for the current network path.
# 
# DPLPMTUD SHOULD only be performed at one layer between a pair of
# endpoints.  Therefore, an upper PL or application should avoid using
# DPLPMTUD when this is already enabled in a lower layer.  A PL MUST
# adjust the MPS indicated by DPLPMTUD to account for any additional
# overhead introduced by the PL.
# 
# +----------------------+
# |     Application*     |
# +-----+------------+---+
#       |            |
#   +---+--+      +--+--+
#   | QUIC*|      |SCTP*|
#   +---+--+      +-+-+-+
#       |           | |
#       +---+  +----+ |
#           |  |      |
#         +-+--+-+    |
#         | UDP  |    |
#         +---+--+    |
#             |       |
# +-----------+-------+--+
# |  Network Interface   |
# +----------------------+
# 
#          Figure 2: Examples Where DPLPMTUD Can Be Implemented
# 
# The central idea of DPLPMTUD is probing by a sender.  Probe packets
# are sent to find the maximum size of user message that can be
# completely transferred across the network path from the sender to the
# destination.
# 
# The following sections identify the components needed for
# implementation, provide an overview of the phases of operation, and
# specify the state machine and search algorithm.

[[spec]]
level = "SHOULD"
quote = '''
DPLPMTUD SHOULD only be performed at one layer between a pair of
endpoints.
'''

[[spec]]
level = "MUST"
quote = '''
A PL MUST
adjust the MPS indicated by DPLPMTUD to account for any additional
overhead introduced by the PL.
'''