DetNet Shaofu. Peng
Internet-Draft ZTE
Intended status: Standards Track Peng. Liu
Expires: 22 December 2024 China Mobile
Kashinath. Basu
Oxford Brookes University
Aihua. Liu
ZTE
Dong. Yang
Beijing Jiaotong University
Guoyu. Peng
Beijing University of Posts and Telecommunications
20 June 2024
Timeslot Queueing and Forwarding (TQF) Control Plane
draft-peng-detnet-tqf-controller-plane-00
Abstract
To achive DetNet QoS in IP/MPLS network and meet the large scaling
requirements, timeslot queueing and forwarding (TQF) mechanism for
enhancing TAS is introduced. This document describes the controller
plane function (CPF) for TQF mechanism.
Status of This Memo
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Copyright (c) 2024 IETF Trust and the persons identified as the
document authors. All rights reserved.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3
2. TQF Path Calculation and Timeslot Resource Reservation . . . 3
2.1. Timeslot Resource Definition . . . . . . . . . . . . . . 4
2.2. Arrival Postion in the Orchestration Period of UNI . . . 6
2.3. Proccess of Each Reservation Sub-task . . . . . . . . . . 9
2.3.1. Resource Reservation on the Ingress Node . . . . . . 10
2.3.2. Resource Reservation on the Transit Node . . . . . . 12
2.3.3. Resource Reservation on the Egress Node . . . . . . . 13
3. Multiple Orchestration Periods . . . . . . . . . . . . . . . 13
4. Flow Aggregation and De-aggregation . . . . . . . . . . . . . 13
5. Provision Flow Identification Information . . . . . . . . . . 14
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14
7. Security Considerations . . . . . . . . . . . . . . . . . . . 14
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 14
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 14
9.1. Normative References . . . . . . . . . . . . . . . . . . 14
9.2. Informative References . . . . . . . . . . . . . . . . . 15
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 15
1. Introduction
DetNet (Deterministic Networking) provides the ability to carry
specified unicast or multicast data flows for real-time applications
with extremely low packet loss rates and assured maximum end-to-end
delivery latency. A description of the general background and
concepts of DetNet can be found in [RFC8655]. In particular,
[RFC8655] defines the Controller Plane Function (CPF), which is in
charge of computing deterministic paths to be applied in the Network
Plane. CPF refers to any device operating in the Controller Plane,
whether it is a Path Computation Element (PCE) [RFC4655], a Network
Management Entity (NME), or a distributed control protocol.
To achive DetNet QoS in IP/MPLS network and meet the large scaling
requirements, [I-D.peng-detnet-packet-timeslot-mechanism] introduces
timeslot queueing and forwarding (TQF) mechanism for enhancing IEEE
802.1 TSN TAS [TAS] (e.g., avoiding time synchronization, timeslot
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based queue allocation rule). It needs to bring timeslot type of
resources to layer-3 and construct timeslot resources on each link
within the repeated gating cycle (also termed as Orchestration
Period). By carefully interleaving flows in different timeslots in
the entire network, TQF can improve flow scale.
This document describes the controller plane function (CPF) for TQF
mechanism.
1.1. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP
14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
2. TQF Path Calculation and Timeslot Resource Reservation
A centralized controller or the network entrance node may calculate a
DetNet path which using TQF scheduling mechanism and can be
abbreviated as a TQF path. A TQF path can provide bounded end-to-end
latency, bounded end-to-end latency jitter, and consume certain burst
and bandwidth resources. A single TQF path may carry multiple DetNet
flows.
The centralized controller, or network nodes involved (through RSVP-
TE [RFC3209], can reserve corresponding timeslot resources along the
TQF path. On each node, for a given incoming timeslot and the
reserved outgoing timeslot, an evaluation of node residence delay can
be obtained.
If a path carries multiple DetNet flows, it may reserve timeslot
resources for the aggregated DetNet flow, and may reserve the burst
resources in multiple timeslots in the orchestration period at the
same time. However, it would still be beneficial to distinguish
between reservation sub-tasks corresponding to different DetNet flows
in the combined reservation task. In this document, we refer to a
reservation sub-task as an individual timeslot resource reservation
action related to a DetNet flow. Note that one or more reservation
sub-tasks for a specific DetNet flow may be derived based on its
TSpec, and each reservation sub-task will allocate corresponding
timeslot. The intermediate nodes do not maintain the state of DetNet
flow and only reserve timeslot resources based on the reservation
sub-tasks.
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During resource reservation, it is necessary to distinguish the
requirements between low latency service and non-low latency service.
For low latency service requirements, the physical offset between the
reserved outgoing timeslot and the incoming timeslot is small; while
for loose latency service requirements, this physical offset can be
large. It is necessary to maintain the end-to-end total residence
delay budget for each reservation sub-task. This is used to select
outgoing timeslot at each node. The sum of residence delays caused
by all nodes should not exceed the total residence delay budget.
Multiple reservation sub-tasks may generate different incoming/
outgoing timeslot mapping relationships on the node. For example:
* The timeslot mapping relationship created by the sub-task-1:
<(incoming port a, incoming slot id 3), (outgoing port b,
outgoing slot id 60)>
* The timeslot mapping relationship created by the sub-task-2:
<(incoming port a, incoming slot id 3), (outgoing port b,
outgoing slot id 61)>
Special care should be taken not to confuse the use of different
mapping relationships for different DetNet flows.
It is recommended, but not mandatory, to reserve timeslot resources
on the outgoing port of each hop from the headend of the path to the
endpoint, that is, first determine the timeslot reserved on the
headend, then determine the timeslot reserved on the next hop , and
so on. A DetNet flow is assumed to have a periodic arrival time
(i.e., the time when the regulated packet arrived at the scheduler),
and there is an ideal position relationship between the arrival time
and the orchestration period of the UNI, so selecting the outgoing
timeslot closed to the arrival time or within the expected offset
range in the orchestration period of NNI can minimize the residency
delay on the headend. However, sometimes it is necessary to get a
larger residence delay on the headend and a smaller residence delay
on other nodes to ensure successful path calculation.
2.1. Timeslot Resource Definition
The timeslot resources of a link can be represented as the
corresponding bit amounts of all timeslots included in an
orchestration period. Basically, the link capability should contain
the following information:
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* Timeslot Length (TL): Represents the length of the timeslot, in
units of us. Generally, the length of each timeslot included in
the orchestration period is the same.
* Orchestration Period Length (OPL): Represents the length of the
orchestration period, in units of us. The orchestration period
contains N timeslots, numbered sequentially from 0 to N-1. That
is, OPL = N*TL.
* Scheduling Period Length (SPL): Represents the length of the
scheduling period, in units of us. The scheduling period contains
M timeslots, numbered sequentially from 0 to M-1. That is, SPL =
M*TL..
Figure 1 shows the timeslot resource model of the link, with an
orchestration period instance consisting of N timeslots numbered from
0 to N-1. The resource information of each timeslot includes the
following attributes:
* Timeslot ID: Indicates the NO. of the timeslot in the
orchestration period instance. The NO. of the first timeslot is
0, and the NO. of the last timeslot is N-1.
* Maximum Reservable Bursts (MRBur): Refers to the maximum amount of
bit quota corresponding to this timeslot, with unit of bits. It
is a configurable preset value that is related to the service rate
(termed as C) and the timeslot length (termed as TL), and the
Maximum Reservable Bursts should be set to a value not exceeding
C*TL. Generally, the Maximum Reservable Bursts of each timeslot
included in the orchestration period are all the same.
* Unreserved Bursts (UBur): Refers to the amount of unreserved bits
reservable corresponding to the timeslot, with unit of bits.
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#N-1 +---------------------------------------+
| Timeslot Length: TL(n-1) |
| Maximum Reservable Bursts: MRBur(n-1) |
| Unreserved Bursts: UBur(n-1) |
+---------------------------------------+
... ... ...
... ... ...
#1 +---------------------------------------+
| Timeslot Length: TL(1) |
| Maximum Reservable Bursts: MRBur(1) |
| Unreserved Bursts: UBur(1) |
+---------------------------------------+
#0 +---------------------------------------+
| Timeslot Length: TL(0) |
| Maximum Reservable Bursts: MRBur(0) |
| Unreserved Bursts: UBur(0) |
+---------------------------------------+
----------------------------------------------------------->
Timeslot Resources of an TQF Instance of the Link
Figure 1: Timeslot Resources Model
The IGP/BGP extensions to advertise the link's capability and
timeslot resource is defined in
[I-D.peng-lsr-deterministic-traffic-engineering].
2.2. Arrival Postion in the Orchestration Period of UNI
On the network entrance node, a DetNet flow, after policing, will
release sub-bursts to the network, with flow pattern that is evenly
distributed within the service burst interval. Each regulated sub-
burst will fall into the ideal incoming timeslot of UNI. Based on
the ideal incoming timeslot, the corresponding ideal outgoing
timeslot of NNI port can be reserved for the sub-burst.
For example, if a DetNet flow distributes m sub-bursts during the
orchestration period, the network entry should maintain m states for
that flow:
* <OPL, ideal incoming slot i_1, ideal outgoing slot z_1>
* <OPL, ideal incoming slot i_2, ideal outgoing slot z_2>
* ... ...
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* <OPL, ideal incoming slot i_m, ideal outgoing slot z_m>
However, the packets arrived at the network entry are not always
ideal, and the departure time from regulator may not be in a certain
ideal incoming timeslot. Therefore, an important operation that
needs to be performed by the network entry is to determine the ideal
incoming timeslot i based on the actual departure time. This can
first determine the actual incoming timeslot based on the actual
departure time, and then select an ideal incoming timeslot that is
closest to the actual incoming timeslot and not earlier than the
actual incoming timeslot.
Figure 2 shows, for some typical DetNet flows, the relationship
between the service burst interval (SBI) and the orchestration period
length (OPL) of UNI, as well as the possible timeslot resource
reservation on NNI for these DetNet flows.
|<--------------------- OPL ---------------------->|
+----+----+----+----+----+----+----+----------+----+
| #0 | #1 | #2 | #3 | #4 | #5 | #6 | ... ... |#N-1|
+----+----+----+----+----+----+----+----------+----+
+--+
Flow 1: | |b1| |
+-----+--+-----------------------------------------+
|<------------------- SBI ------------------------>|
+--+ +--+
Flow 2: | |b1| |b2|
+------------+--+------------------------+--+------+
|<------------------- SBI ------------------------>|
+------+
Flow 3: | | b1 |
+---------------------------+------+---------------+
|<------------------- SBI ------------------------>|
+--+ +--+ +--+
Flow 4: | |b1| | |b1| | |b1| |
+----+--+--------+----+--+--------+----+--+--------+
|<----- SBI ---->|<----- SBI ---->|<----- SBI ---->|
Figure 2: Relationship between SBI and OP
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As shown in the figure, the length of service burst intervals for
flows 1, 2, 3 is equal to the length of orchestration period, while
the length of the service burst interval for flow 4 is only 1/3 of
the orchestration period.
* Flow 1 generates a small single burst amounts within its burst
interval, which may reserve timeslot 2 or other subsequent
timeslot in the orchestration period;
* Flow 2 generates two small discrete sub-bursts within its burst
interval and also be shaped, which may reserve slots 4 and N-1 in
the orchestration period for each sub-burst respectively;
* Flow 3 generates a large single burst amount within its burst
interval but not be really shaped (due to purchasing a larger
burst resource and served by a larger bucket depth), which may
also be split to multiple back-to-back sub-bursts and reserve
multiple timeslots in the orchestration period, such as timeslots
8 and 9.
* The length of the service burst interval for flow 4 is only 1/3 of
the orchestration period. Hence, construct flow 4' with 3
occurrence of the flow 4 within an orchestration period. So flow
4' is similar to flow 2, generating a small amount of three
separate sub-bursts within its burst interval. It may reserve
timeslots 3, 7, and N-1 in the orchestration period.
Each sub-burst corresponds to a reservation sub-task. For
simplicity, each regulated sub-burst in the service burst interval
always reserves timeslot resources according to the maximum sub-bust
size.
For a specific DetNet flow, to determine how many reservation sub-
tasks are required, can be summarized as:
* First, align the service burst interval with the orchestration
period of UNI to ensure that the two are of equal length. If the
service burst interval is only a fraction of the orchestration
period, multiply it several times to obtain the expanded service
burst interval to get a new flow'.
* Check how many discrete sub-bursts will be generated during the
orchestration period, and for each sub-burst:
- If the proportion of the sub-burst size to the MRB of a single
timeslot does not exceed a specific value, then the sub-burst
corresponds to a reservation sub-task;
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- Otherwise, continue to split the sub-burst into multiple sub-
sub-bursts, so that the proportion of each sub-sub-burst size
to the MRB of a single timeslot does not exceed the specific
value, and each sub-sub-burst corresponds to a reservation sub-
task.
2.3. Proccess of Each Reservation Sub-task
Each reservation sub-task contains a separate parameter set, which is
used in the process of timeslot resource reservation. Note that this
set may be a local information for the path compuation engine (e.g, a
controller), or may signal between nodes (e.g, RSVP-TE).
* Total Residence Budget: It is the sum of the residence delay
allowed by the DetNet flow within all nodes in the path, which is
equal to the end-to-end delay requirement of the DetNet flow minus
the propagation delay of all links included in the path.
* Node Residence Budget: It refers to the residence delay budget of
the current node traversed during the process of reserving
timeslot resources on each node along the path in sequence. A
simple way is to divide the Total Residence Budget by the number
of nodes included in the path to obtain the average residence
delay budget as the Node Residence Budget for each node, or use a
specified budget list to specify the residence delay budget for
each node separately.
* Accumulated Node Residence Budget: It refers to the accumulated
residence delay budget of those nodes that have executed resource
reservation.
* Accumulated Node Residence Evaluation: It refers to the
accumulated evaluation value of the residence delay of nodes that
have executed resource reservation. The residence delay
evaluation value of a node refers to the residence delay
evaluation value calculated based on the delay formula (see below)
when the node actually reserves a certain outgoing timeslot for
the reservation sub-task. Generally, if a node is able to reserve
the expected outgoing timeslot according to its residence delay
budget, the residence delay evaluation value does not differ from
the residence delay budget. However, in some cases, due to
insufficient resources in the expected timeslot, resources have to
be reserved in the timeslot adjacent to the expected timeslot,
which can lead to a difference between the residence delay
evaluation value and the budget value.
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* Accumulated Node Residence Deviation: It is equal to the
Accumulated Node Residence Budget minus the Accumulated Node
Residence Evaluation.
* Node Residence Budget Adjustment: It is equal to the Node
Residence Budget plus the Accumulated Node Residence Deviation.
The usage for the above parameter set is:
* For specific reservation sub-task, determine the Node Residence
Budget for each node in the path, which can be taken from the
average residence delay budget per node or the specified budget
list.
* From the headend to the endpoint, on each node's outgoing port in
sequence, reserve outgoing timeslot resources based on the Node
Residence Budget Adjustment, to let the residence delay evaluation
value of the node obtained from the reserved outgoing timeslot be
equal to or close to the Node Residence Budget Adjustment.
- On the headend, the Accumulated Node Residence Deviation is the
initial value of 0. Therefore, the Node Residence Budget
Adjustment is equal to the Node Residence Budget.
- On any other nodes, the Accumulated Node Residence Deviation is
generally not 0. If the residence delay evaluation value of
the node obtained from the reserved outgoing timeslot be equal
to the Node Residence Budget Adjustment, it will cause the
Accumulated Node Residence Deviation faced by the downstream
node in the path to be 0 again.
Note that the above parameter set is only an implementation choice
and is not mandatory. There may be more intelligent path calculation
methods available.
2.3.1. Resource Reservation on the Ingress Node
On the headend H, as mentioned above, each sub-burst corresponds to
an ideal incoming timeslot i of UNI port. After the intra-node
forwarding delay (F), the end of the incoming timeslot i reaches the
outgoing port, the timeslot currently in the sending state (i.e., the
ongoing sending timeslot of NNI port) is j, and there is time T_ij
left before the end of the timeslot j.
The outgoing timeslot reserved for the sub-burst by the headend is
offset by o (>=1) timeslots after timeslot j, which means the
outgoing timeslot is z = (j+o)%N_nni, where N_nni is the number of
timeslots in the orchestration period of NNI port.
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Note that o must be less than M. (where o is the offset and M is the
number of timeslot in the scheduling period as mentioned in
Section 2.1)
Thus, on the headend H the residence delay evaluation value obtained
from the reserved outgoing timeslot z is:
Best Node Residence Evaluation = F + T_ij + (o-1)*L_nni
Worst Node Residence Evaluation = F + L_uni + T_ij + o*L_nni
Average Node Residence Evaluation = F + T_ij + (L_uni + (2o-
1)*L_nni)/2
where, L_uni is the timeslot length of UNI port, L_nni is the
timeslot length of NNI port.
The Best Node Residence Evaluation occurs when the sub-burst is at
the end of the ideal incoming timeslot i, and sent at the head of
outgoing timeslot z. The Worst Node Residence Evaluation occurs when
the sub-burst is at the head of the ideal incoming timeslot i, and
sent at the end of outgoing timeslot z. The delay jitter within the
headend is (L_uni + L_nni). However, the jitter of the entire path
is not the sum of the jitters of all nodes.
Depending on the implementation, the above Best Node Residence
Evaluation, Worst Node Residence Evaluation, or Average Node
Residence Evaluation can be used to compare with the Node Residence
Budget Adjustment, so that when selecting the appropriate outgoing
timeslot z, the two are equal or nearly equal, and the corresponding
Unreserved Burst resources of the outgoing timeslot z meet the burst
demand of the sub-burst. However, this document suggests using the
Average Node Residence Evaluation to compare with the Node Residence
Budget Adjustment, because the characteristic of the forwarding
behavior based on TQF is that adjacent nodes on the path will not
simultaneously face the best or worst residency delay.
Note that there is a runtime jitter (i.e., the resource reservation
process on the control plane is not aware of it), as mentioned
earlier, which depends on the deviation between the actual incoming
timeslot i' and the ideal incoming timeslot i. Assuming that i =
(i'+e)%N_uni, where e is the deviation, N_uni is the number of
timeslots in the orchestration period of UNI port, then the
additional runtime jitter is e*L_uni, that should be carried in the
packet to eliminate jitter at the network egress.
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2.3.2. Resource Reservation on the Transit Node
On the transit node V, there is a timeslot mapping relationship
between the incoming timeslot i and the ongoing sending timeslot j of
outgoing port, and there is time T_ij left before the end of the
timeslot j.
For a specific sub-task with incoming timeslot i, assuming the
outgoing timeslot z is reserved for it, by o (>=1) timeslots after
timeslot j, i.e., z = (j+o)%N_out, where N_out is the number of
timeslots in the orchestration period of port_out.
Note that o must be less than M.
Thus, on the transit node V the residence delay evaluation value
obtained from the reserved outgoing timeslot z is:
Best Node Residence Evaluation = F + T_ij + (o-1)*L_out
Worst Node Residence Evaluation = F + T_ij + L_in + o*L_out
Average Node Residence Evaluation = F + T_ij + (L_in+(2o-
1)*L_out)/2
where, L_in and L_out is the length of incoming timeslot and
outgoing timeslot respectively.
The Best Node Residence Evaluation occurs when the packet is received
at the end of incoming timeslot i and sent at the head of outgoing
timeslot z; The Worst Node Residence Evaluation occurs when the
packet is received at the head of incoming timeslot i and sent at the
end of outgoing timeslot z. The delay jitter within the node is
(L_in + L_out). However, the jitter of the entire path is not the
sum of the jitters of all nodes.
Depending on the implementation, the above Best Node Residence
Evaluation, Worst Node Residence Evaluation, or Average Node
Residence Evaluation can be used to compare with the Node Residence
Budget Adjustment, so that when selecting the appropriate outgoing
timeslot z, the two are equal or nearly equal, and the corresponding
Unreserved Burst resources of the outgoing timeslot z meet the burst
demand of the sub-burst. However, this document suggests using the
Average Node Residence Evaluation to compare with the Node Residence
Budget Adjustment, because the characteristic of the forwarding
behavior based on TQF is that adjacent nodes on the path will not
simultaneously face the best or worst residency delay.
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2.3.3. Resource Reservation on the Egress Node
Generally, for the deterministic path carrying the DetNet flow, the
flow needs to continue forwarding from the outgoing port of the
egress node to the client side, and also faces the issues of
queueing. However, the outgoing port facing the client side is not
part of the deterministic path. If it is necessary to continue
supporting TQF mechanism on that port, timeslot resources should be
reserved on the higher-level DetNet path (an overlay path) using the
above reservation method. In this case, the underlay DetNet path
will serve as a virtual link of the overlay path, providing a
deterministic delay performance.
Therefore, for deterministic paths, the residence dalay evaluation
value on the egress node is only contributed by the forwarding delay
(F) including parsing, table lookup, internal fabric exchange, etc.
3. Multiple Orchestration Periods
Multiple orchestration periods each with different length may be
provided by the link.
Interworking between different nodes is based on the same
orchestration period. That means that the timeslot resource
reservation along the path for a sub-task should be in the context of
the specific orchestration period.
4. Flow Aggregation and De-aggregation
Multiple DetNet flows may share the same timeslot resources on each
link included in a certain path segment in the network. These flows
are simply encapsulated with the same timeslot id during forwarding.
TQF allows for different lengths of incoming and outgoing timeslots,
which is useful for natural flow aggregation caused by the network
topology (such as access, aggregation and backbone domains). For
example, for the direction from the access domain to the aggregation
domain, on the aggregation point, the incoming timeslot length may be
larger than the outgoing timeslot length, and multiple incoming
timeslots will be mapped to the same outgoing timeslot. Generally,
the capacity of a short outgoing timeslot is still larger than that
of a long incoming timeslot, otherwise, the aggregated incoming
timeslots will be mapped to several consecutive outgoing timeslots.
Switching from a long incoming timeslot to a short outgoing timeslot
will accelerate packet forwarding.
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In the opposite direction, on the de-aggregation point, a single
incoming timeslot may be mapped to multiple outgoing timeslots each
for a specific outgoing port, if the capacity of the incoming
timeslot is larger than that of the outgoing timeslot.
5. Provision Flow Identification Information
TQF use outgoing timeslot id on each node to provide PHB treatment
for flows in the network. A DetNet flow will obtain the outgoing
timeslot id stack once the related path is calculated and setup.
Essentially, the use of timeslot id is a function of the forwarding
sub-layer
An additional flow identification is still necessary for a DetNet
flow that is sent on the TQF path, for the purpose of service sub-
layer functions such as PREOF (Packet Replication, Elimination and
Ordering Functions). The flow identification should also be
determined for the flow once the related path is calculated and
setup. This provision is a common operation and not unique to TQF.
6. IANA Considerations
TBD.
7. Security Considerations
TBD.
8. Acknowledgements
TBD.
9. References
9.1. Normative References
[I-D.peng-detnet-packet-timeslot-mechanism]
Peng, S., Liu, P., Basu, K., Liu, A., Yang, D., and G.
Peng, "Timeslot Queueing and Forwarding Mechanism", Work
in Progress, Internet-Draft, draft-peng-detnet-packet-
timeslot-mechanism-06, 4 March 2024,
<https://datatracker.ietf.org/doc/html/draft-peng-detnet-
packet-timeslot-mechanism-06>.
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[I-D.peng-lsr-deterministic-traffic-engineering]
Peng, S., "IGP Extensions for Deterministic Traffic
Engineering", Work in Progress, Internet-Draft, draft-
peng-lsr-deterministic-traffic-engineering-01, 4 July
2023, <https://datatracker.ietf.org/doc/html/draft-peng-
lsr-deterministic-traffic-engineering-01>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V.,
and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP
Tunnels", RFC 3209, DOI 10.17487/RFC3209, December 2001,
<https://www.rfc-editor.org/info/rfc3209>.
[RFC4655] Farrel, A., Vasseur, J.-P., and J. Ash, "A Path
Computation Element (PCE)-Based Architecture", RFC 4655,
DOI 10.17487/RFC4655, August 2006,
<https://www.rfc-editor.org/info/rfc4655>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[RFC8655] Finn, N., Thubert, P., Varga, B., and J. Farkas,
"Deterministic Networking Architecture", RFC 8655,
DOI 10.17487/RFC8655, October 2019,
<https://www.rfc-editor.org/info/rfc8655>.
9.2. Informative References
[TAS] "Time-Aware Shaper", 2015,
<https://standards.ieee.org/ieee/802.1Qbv/6068/>.
Authors' Addresses
Shaofu Peng
ZTE
China
Email: peng.shaofu@zte.com.cn
Peng Liu
China Mobile
China
Email: liupengyjy@chinamobile.com
Peng, et al. Expires 22 December 2024 [Page 15]
Internet-Draft TQF Control Plane June 2024
Kashinath Basu
Oxford Brookes University
United Kingdom
Email: kbasu@brookes.ac.uk
Aihua Liu
ZTE
China
Email: liu.aihua@zte.com.cn
Dong Yang
Beijing Jiaotong University
China
Email: dyang@bjtu.edu.cn
Guoyu Peng
Beijing University of Posts and Telecommunications
China
Email: guoyupeng@bupt.edu.cn
Peng, et al. Expires 22 December 2024 [Page 16]