Outline of an Amendment toIEEE Std 802.1Q for Pulsed Queuing
Norman Finn
Huawei Technologies Co. Ltd
nfinn@nfinnconsulting.com
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Specific clauses inIEEE Std 802.1Q-2022/3
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Preface● This presentation assumes that a Pulsed Queuing PAR would
amend IEEE Std 802.1Q-2022/3.
● The terminology used in this presentation is, obviously, subject toradical change.
● Because of the similarities among the ATS, MCQF, and paternoster
algorithms, there is more than one way to describe the aggregate,
and more than one way to specify managed objects to makechoices. This presentation offers one approach, in order to showthat it is possible to write a reasonable amendment. It is notnecessary to finalize that choice in order to write the PAR.
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Pulsed Queuing is a variant ofAsynchronous Traffic Shaping (ATS)● Pulsed Queuing could use the same model for transmission
selection as ATS, based on eligibility time. A Pulsed Queuing “bin”
is just some number of frames with the same eligibility time.
● Pulsed Queuing could use a bin-based model, using integers toselect bins, instead of eligibility times.
● There are arguments for both approaches; there is not time toexplore them at this moment. For this presentation, we willassume a time-based approach, in order to maximize commonality
with the current document, and to minimize the number ofconcepts explained.
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Synchronization● For MCQF, syntonization with neighbors of bin rotation is essential.
● For paternoster, syntonization of bin rotation is a useful option:● It reduces the end-to-end latency variation.
● It can be use in for policing, to remove the transitive trust issue with simple
MCQF.

● For both MCQF and paternoster, if multiple queues are used withdifferent bin periods, they must be syntonized with each other (ifnot with the network) and have integral period ratios.

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Clause 8.6.8 Transmission selection● Paternoster, MCQF, and ATS all use the same basic queue
structure, organized around eligibility time.
● Syntonizing that queue with the network is pointless but harmless
for ATS, a useful option for paternoster, and essential for MCQF.
Inter-queue syntonization is required for MCQF and paternoster.
● Thus, in 8.6.8 Table 8-6, we re-label option 3, ATS, as “time-basedtransmission (ATS, paternoster, MCQF.
● We add 8.6.8.last, to explain the required syntonization andfrequency relationships among pulsed queues with differentperiods.
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Clause 8.6.5
Flow classification and metering● We use two new methods for assigning each frame an eligibility
time, both different from the one defined currently for ATS:

● A “paternoster” scheme that counts transmission-time bits for each streamand ensures that no more than the maximum for that stream is stored with
into one bin.
● A “Multi Cyclic Queuing and Forwarding” (MCQF) scheme that computes theeligibility time based on the arrival time of the frame.

● So, we add new subclauses:
8.6.5.7 Paternoster eligibility time assignment
8.6.5.8 MCQF eligibility time assignment● The introduction to FC&M in 8.6.5 must be modified, of course.
● How much of 8.6.5.2.3 needs to be modified or replicated is TBD.
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Clause 5 Conformance● Add options for VLAN Bridge components:
5.4.1.last Paternoster• Eligibility time assignment by paternoster algorithm● 5.4.1.last+1 MCQF
• Eligibility time assignment by MCQF algorithm● Similar options for:
● MAC Bridge component 5.13.1.last (two clauses, paternoster and MCQF)● End station 5.last (paternoster, no MCQF).

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Managed objects, MIBs, and YANG
Add managed objects, MIBs, and YANG for:● Controlling MCQF
● Controlling paternoster● In both cases, this is done in a straightforward manner, without
requiring both MCQF and paternoster, or requiring a full ATS
implementation, and in a manner that enables the use of both
MCQF and paternoster on the same queue.

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9Annex● Add a new annex for MCQF/paternoster covering:● Pulsed queues for MCQF/paternoster can be implemented as a simplified
ATS queue.
● Calculating per-hop and end-to-end latencies and buffer requirements. This
includes explanations of the tradeoff between per-hop latency and per-cycle
dead time.
● Consideration of the effect on latency and buffer space of aggregating anddis-aggregating flows.

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Thank you
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