Draft: draft-ietf-detnet-mpls

Commentary: Proposed changes : 0 , fixing   < discusscomment 1 , change introduction to highlight additional functions of data plane and the focus of the draft 2 , highlight that implementation of PREOF is out of scope , pointing to related IEEE work ( i.e. , 802.1CB ) 3 , fixing the POF section and its configuration via controller plane
Paragraph (version A):
The DetNet Architecture models the DetNet related data plane
functions decomposed into two sub-layers: a service sub-layer and a
forwarding sub-layer.  The service sub-layer is used to provide
DetNet service functions such as protection and reordering.  The
forwarding sub-layer is used to provide forwarding assurance (low
loss, assured latency, and limited out-of-order delivery).
Paragraph (version B):
The purpose of this document is to describe the use of the MPLS data
plane to establish and support DetNet flows.  The DetNet Architecture
models the DetNet related data plane functions decomposed into two
sub-layers: a service sub-layer and a forwarding sub-layer.  The
service sub-layer is used to provide DetNet service functions such as
protection and reordering.  At the DetNet data plane a new set of
functions (PREOF) provide the service sub-layer specific tasks.  The
forwarding sub-layer is used to provide forwarding assurance (low
loss, assured latency, and limited out-of-order delivery) via already
existing Traffic Engineering and queuing tools.  The use of the
functionalities of the DetNet service sub-layer and the DetNet
forwarding sub-layer require careful design and control by the
controller plane in addition to the DetNet specific use of MPLS
encapsulation as specified by this document.
Paragraph (version B):
Implementation details of PREOF functions is out of scope for this
document.  IEEE802.1CB-2017 specifies replication and elimination
specific aspects, which can be applied to PRF and PEF.
Paragraph (version B):
The latency impact on the system resources needed to support a
specific DetNet flow will need to be evaluated by the controller
plane based on that flow's traffic specification.  An example traffic
specification that can be used with MPLS with Traffic Engineering
(MPLS-TE) can be found in RFC2212.
Paragraph (version B):
DetNet uses flow-specific requirements (e.g., maximum number of out-
of-order packets, maximum latency of the flow) for configuration of
POF-related buffers.  POF implementation details are out-of-scope for
this document and POF configuration parameters are implementation
specific.  The Controller Plane determines and sets the POF
configuration parameters.  If PEF is combined with POF, then their
configurations need to be coordinated to ensure the combined
functionality.
Paragraph (version A):
To provide uninterrupted availability of the DetNet service,
provisions can be made against DOS attacks and delay attacks.  To
protect against DOS attacks, excess traffic due to malicious or
malfunctioning devices is prevented or mitigated through the use of
existing mechanisms, for example by policing and shaping incoming
traffic.  To prevent DetNet packets from being delayed by an entity
external to a DetNet domain, DetNet technology definition can allow
for the mitigation of on-path attackers, for example through use of
authentication and authorization of devices within the DetNet domain.
Paragraph (version B):
To provide uninterrupted availability of the DetNet service,
provisions can be made against DOS attacks and delay attacks.  To
protect against DOS attacks, excess traffic due to malicious or
malfunctioning devices is prevented or mitigated through the use of
existing mechanisms, for example by policing and shaping incoming
traffic.  To prevent DetNet packets having their delay manipulated by
an external entity, precautions need to be taken to ensure that all
devices on an LSP are those intended to be there by the network
operator and that they are well behaved.  In addition to physical
security, technical methods such as authentication and authorization
of network equipment and the instrumentation and monitoring of the
LSP packet delay may be used.  If a delay attack is suspected,
traffic may be moved to an alternate path, for example through
changing the LSP or management of the PREOF configuration.