Draft: draft-ietf-detnet-ip-over-tsn

Commentary: Fixing conformance language Adding more definite references for TSN functions ( i.e. , Clause numbers )
Paragraph (version A):
Congestion protection, latency control and the resource allocation
(queuing, policing, shaping) are supported using the underlying link
/ sub-net specific mechanisms.  Service protections (packet
replication and packet elimination functions) are not provided at the
DetNet layer end to end due the lack of a unified end to end
sequencing information that would be available for intermediate
nodes.  However, such service protection can be provided on a per
underlying L2 link and sub-network basis.
Paragraph (version B):
Congestion protection, latency control and the resource allocation
(queuing, policing, shaping) are supported using the underlying link
/ sub-net specific mechanisms.  Service protections (packet
replication and packet elimination functions) are not provided at the
DetNet layer end-to-end due the lack of a unified end-to-end
sequencing information that would be available for intermediate
nodes.  However, such service protection can be provided on a per
underlying L2 link and sub-network basis.
Paragraph (version A):
The Time-Sensitive Networking (TSN) Task Group of the IEEE 802.1
Working Group have defined (and are defining) a number of amendments
to IEEE8021Q that provide zero congestion loss and bounded latency in
bridged networks.  Furthermore IEEE8021CB defines frame replication
and elimination functions for reliability that should prove both
compatible with and useful to DetNet networks.  All these functions
have to identify flows that require TSN treatment.
Paragraph (version A):
TSN capabilities of the TSN sub-network are made available for IP
(DetNet) flows via the protocol interworking function defined in
IEEE8021CB.  For example, applied on the TSN edge port it can convert
an ingress unicast IP (DetNet) flow to use a specific Layer-2
multicast destination MAC address and a VLAN, in order to direct the
packet through a specific path inside the bridged network.  A similar
interworking function pair at the other end of the TSN sub-network
would restore the packet to its original Layer-2 destination MAC
address and VLAN.
Paragraph (version A):
Placement of TSN functions depends on the TSN capabilities of nodes.
IP (DetNet) Nodes may or may not support TSN functions.  For a given
TSN Stream (i.e., DetNet flow) an IP (DetNet) node is treated as a
Talker or a Listener inside the TSN sub-network.
Paragraph (version A):
Mapping of a DetNet IP flow to a TSN Stream is provided via the
combination of a passive and an active stream identification function
that operate at the frame level.  The passive stream identification
function is used to catch the 6-tuple of a DetNet IP flow and the
active stream identification function is used to modify the Ethernet
header according to ID of the mapped TSN Stream.
Paragraph (version A):
IEEE8021CB defines an IP Stream identification function that can be
used as a passive function for IP DetNet flows using UDP or TCP.
IEEEP8021CBdb defines a Mask-and-Match Stream identification function
that can be used as a passive function for any IP DetNet flows.
Paragraph (version A):
IEEE8021CB defines an Active Destination MAC and VLAN Stream
identification function, what can replace some Ethernet header fields
namely (1) the destination MAC-address, (2) the VLAN-ID and (3)
priority parameters with alternate values.  Replacement is provided
for the frame passed down the stack from the upper layers or up the
stack from the lower layers.
Paragraph (version B):
The Time-Sensitive Networking (TSN) Task Group of the IEEE 802.1
Working Group have defined (and are defining) a number of amendments
to IEEE8021Q that provide zero congestion loss and bounded latency in
bridged networks.  Furthermore, IEEE8021CB defines frame replication
and elimination functions for reliability that should prove both
compatible with and useful to DetNet networks.  All these functions
have to identify flows that require TSN treatment.
Paragraph (version B):
TSN capabilities of the TSN sub-network are made available for IP
(DetNet) flows via the protocol interworking function desribed in
Annex C.5 of IEEE8021CB.  For example, applied on the TSN edge port
it can convert an ingress unicast IP (DetNet) flow to use a specific
Layer-2 multicast destination MAC address and a VLAN, in order to
direct the packet through a specific path inside the bridged network.
A similar interworking function pair at the other end of the TSN sub-
network would restore the packet to its original Layer-2 destination
MAC address and VLAN.
Paragraph (version B):
Placement of TSN functions depends on the TSN capabilities of nodes.
IP (DetNet) Nodes may or may not support TSN functions.  For a given
TSN Stream (i.e., a mapped DetNet flow) an IP (DetNet) node is
treated as a Talker or a Listener inside the TSN sub-network.
Paragraph (version B):
Mapping of a DetNet IP flow to a TSN Stream is provided via the
combination of a passive and an active stream identification function
that operate at the frame level (Layer-2).  The passive stream
identification function is used to catch the 6-tuple of a DetNet IP
flow and the active stream identification function is used to modify
the Ethernet header according to the ID of the mapped TSN Stream.
Paragraph (version B):
Clause 6.7 of IEEE8021CB defines an IP Stream identification function
that can be used as a passive function for IP DetNet flows using UDP
or TCP.  Clause 6.8 of IEEEP8021CBdb defines a Mask-and-Match Stream
identification function that can be used as a passive function for
any IP DetNet flows.
Paragraph (version B):
Clause 6.6 of IEEE8021CB defines an Active Destination MAC and VLAN
Stream identification function, what can replace some Ethernet header
fields namely (1) the destination MAC-address, (2) the VLAN-ID and
(3) priority parameters with alternate values.  Replacement is
provided for the frame passed down the stack from the upper layers or
up the stack from the lower layers.
Paragraph (version A):
This section covers required behavior of a TSN-aware DetNet node
using a TSN sub-network.
Paragraph (version B):
This section covers required behavior of a TSN-aware DetNet node
using a TSN sub-network.  The implementation of TSN packet processing
functions MUST be compliant with the relevant IEEE 802.1 standards.
Paragraph (version A):
A TSN-aware IP (DetNet) node implementations MUST support the
Sequencing function and the Sequence encode/decode function as
defined in IEEE8021CB if FRER is used inside the TSN sub-network.
Paragraph (version A):
A TSN-aware IP (DetNet) node implementations MUST support the Stream
splitting function and the Individual recovery function as defined in
IEEE8021CB when the node is a replication or elimination point for
FRER.
Paragraph (version A):
TSN Streams supporting DetNet flows may use Frame Replication and
Elimination for Redundancy (FRER) as defined in IEEE8021CB based on
the loss service requirements of the TSN Stream, which is derived
from the DetNet service requirements of the DetNet mapped flow.  The
specific operation of FRER is not modified by the use of DetNet and
follows IEEE8021CB.
Paragraph (version B):
A TSN-aware IP (DetNet) node implementations MUST support the
Sequencing function and the Sequence encode/decode function as
defined in Clause 7.4 and 7.6 of IEEE8021CB if FRER is used inside
the TSN sub-network.
Paragraph (version B):
A TSN-aware IP (DetNet) node implementations MUST support the Stream
splitting function and the Individual recovery function as defined in
Clause 7.7 and 7.5 of IEEE8021CB when the node is a replication or
elimination point for FRER.
Paragraph (version B):
TSN Streams supporting DetNet flows may use Frame Replication and
Elimination for Redundancy (FRER) as defined in Clause 8. of
IEEE8021CB based on the loss service requirements of the TSN Stream,
which is derived from the DetNet service requirements of the DetNet
mapped flow.  The specific operation of FRER is not modified by the
use of DetNet and follows IEEE8021CB.
Paragraph (version B):
DetNet IP related configuration information according to the
DetNet role of the DetNet IP node, as per I-D.ietf-detnet-ip.
Paragraph (version B):
TSN related configuration information according to the TSN role of
the DetNet IP node, as per IEEE8021Q, IEEE8021CB and
IEEEP8021CBdb.
Paragraph (version B):
Mapping between DetNet IP flow(s) (as flow identification defined
in I-D.ietf-detnet-ip, it is summarized in Section 5.1 of that
document, and includes all wildcards, port ranges and the ability
to ignore specific IP fields) and TSN Stream(s) (as stream
identification information defined in IEEE8021CB and
IEEEP8021CBdb).  Note, that managed objects for TSN Stream
identification can be found in IEEEP8021CBcv.
Paragraph (version B):
This information MUST be provisioned per DetNet flow.
Paragraph (version A):
In order to use a TSN sub-network between DetNet nodes, DetNet
specific information must be converted to TSN sub-network specific
ones.  DetNet flow ID and flow related parameters/requirements must
be converted to a TSN Stream ID and stream related parameters/
requirements.  Note that, as the TSN sub-network is just a portion of
the end2end DetNet path (i.e., single hop from IP perspective), some
parameters (e.g., delay) may differ significantly.  Other parameters
(like bandwidth) also may have to be tuned due to the L2
encapsulation used within the TSN sub-network.
Paragraph (version B):
In order to use a TSN sub-network between DetNet nodes, DetNet
specific information must be converted to TSN sub-network specific
ones.  DetNet flow ID and flow related parameters/requirements must
be converted to a TSN Stream ID and stream related parameters/
requirements.  Note that, as the TSN sub-network is just a portion of
the end-to-end DetNet path (i.e., single hop from IP perspective),
some parameters (e.g., delay) may differ significantly.  Other
parameters (like bandwidth) also may have to be tuned due to the L2
encapsulation used within the TSN sub-network.
Paragraph (version A):
The security considerations of DetNet in general are discussed in
RFC8655 and I-D.ietf-detnet-security.  DetNet IP data plane specific
considerations are summarized in I-D.ietf-detnet-ip.  Encryption may
provided by an underlying sub-net using MACSec IEEE802.1AE-2018 for
DetNet IP over TSN flows.
Paragraph (version B):
Security considerations for DetNet are described in detail in I-
D.ietf-detnet-security.  General security considerations are
described in RFC8655.  DetNet IP data plane specific considerations
are summarized in I-D.ietf-detnet-ip.  This section considers
exclusively security considerations which are specific to the DetNet
IP over TSN sub-network scenario.
Paragraph (version B):
The sub-network between DetNet nodes needs to be subject to
appropriate confidentiality.  Additionally, knowledge of what DetNet/
TSN services are provided by a sub-network may supply information
that can be used in a variety of security attacks.  The ability to
modify information exchanges between connected DetNet nodes may
result in bogus operations.  Therefore, it is important that the
interface between DetNet nodes and TSN sub-network are subject to
authorization, authentication, and encryption.
Paragraph (version B):
The TSN sub-network operates at Layer-2 so various security
mechanisms defined by IEEE can be used to secure the connection
between the DetNet nodes (e.g., encryption may be provided using
MACSec IEEE802.1AE-2018).