Internet DRAFT - draft-finn-bounded-latency
draft-finn-bounded-latency
DetNet N. Finn
Internet-Draft Huawei Technologies Co. Ltd
Intended status: Standards Track B. Varga
Expires: May 3, 2018 J. Farkas
Ericsson
October 30, 2017
DetNet Bounded Latency
draft-finn-bounded-latency-00
Abstract
This document a model for DetNet to achieve bounded latency and zero
congestion loss using existing and in-progress standards from IEEE
802 and RFCs from IETF.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Conventions Used in This Document . . . . . . . . . . . . . . 3
3. Terminology and Definitions . . . . . . . . . . . . . . . . . 3
4. Timing Model . . . . . . . . . . . . . . . . . . . . . . . . 3
4.1. Delay Model . . . . . . . . . . . . . . . . . . . . . . . 3
4.2. Achieving zero congestion loss . . . . . . . . . . . . . 5
5. Queuing model . . . . . . . . . . . . . . . . . . . . . . . . 6
5.1. Queuing data model . . . . . . . . . . . . . . . . . . . 6
5.2. Queuing Data Model with Preemption . . . . . . . . . . . 8
5.3. Transmission Selection Model . . . . . . . . . . . . . . 9
6. Extending the queuing model . . . . . . . . . . . . . . . . . 11
6.1. Complex delay models . . . . . . . . . . . . . . . . . . 11
6.2. Extending the 802.1Q model to routers . . . . . . . . . . 12
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 13
7.1. Normative References . . . . . . . . . . . . . . . . . . 14
7.2. Informative References . . . . . . . . . . . . . . . . . 15
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 16
1. Introduction
The ability for IETF Deterministic Networking (DetNet) or IEEE 802.1
Time-Sensitive Networking (TSN) to provide bounded latency and zero
congestion loss depends upon A) configuring and allocating network
resources for the exclusive use of DetNet/TSN flows; B) identifying,
in the data plane, the resources to be utilized by any given packet,
and C) the detailed behavior of those resources, especially
transmission queue selection, so that latency bounds can be reliably
assured. Thus, DetNet is an example of an INTSERV Guaranteed Quality
of Service [RFC2212]
As explained in [I-D.ietf-detnet-architecture], DetNet flows are
characterized by 1) a maximum bandwidth, guaranteed either by the
transmitter or by strict input metering; and 2) a requirement for a
guaranteed worst-case end-to-end latency. That latency guarantee, in
turn, provides the opportunity to supply enough buffer space to
guarantee zero congestion loss. To be of use to the applications
identified in [I-D.ietf-detnet-use-cases], it must be possible to
calculate, before the transmission of a DetNet flow commences, the
worst-case network latency and the amount of buffer space required at
each hop to ensure against congestion loss. The detailed behavior of
the mechanism(s) used to select the next packet for transmission at
each output port is critical in making this determination. A
detailed timing model, breaking down the time taken for each packet
to traverse each element in the model, along with possible
variations, is required, because seemingly minor implementation
variations can generate large uncertainties in the number of required
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buffers. Such inconsistencies must be identified, and where
possible, minimized. This timing model must also include non-TSN/
DetNet queuing techniques insofar their use can affect the DetNet
flows.
The IEEE 802.1 Working Group has standardized a number of specific
techniqueues that can be used by routers or hosts. These documents
include [IEEE8021Q] (Clause 34), [IEEE802.1Qch], [IEEE802.1Qci],
[IEEE8021Qbv], [IEEE8021Qbu], [IEEE8023br].
[[NOTE (to be removed from a future revision): The queuing and
transmission selection methods defined in IEEE 802.1Q and its
amendments are all in the context of implementing those methods in an
802.1Q bridge; they are not all specified for use in an end station,
much less in a router. It is the intention of the authors of this
draft to create a document in some Standards Development Organization
(SDO) that provides normative reference points for a document from
any SDO describing any device, e.g. a host or a router. That would
make the 802.1 queuing techniques readily available to a router or
host. As that document develops, so too will this draft evolve.]]
2. Conventions Used in This Document
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119].
The lowercase forms with an initial capital "Must", "Must Not",
"Shall", "Shall Not", "Should", "Should Not", "May", and "Optional"
in this document are to be interpreted in the sense defined in
[RFC2119], but are used where the normative behavior is defined in
documents published by SDOs other than the IETF.
3. Terminology and Definitions
This document uses the terms defined in
[I-D.ietf-detnet-architecture].
4. Timing Model
4.1. Delay Model
In Figure 1 we see a breakdown of the per-hop latency experienced by
a packet in terms that are suitable for computing both hop-by-hop
latency, and per-hop buffer requirements.
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DetNet relay node A DetNet relay node B
+-----------------+ +-----------------+
| Queue | | Queue |
| +-+-+-+ | | +-+-+-+ |
-->+ | | | + +------->+ | | | + +--->
| +-+-+-+ | | +-+-+-+ |
| | | |
+-----------------+ +-----------------+
|<----->|<--->|<->|<------>|<----->|<--->|<->|<--
2,3 4 5 1 2,3 4 5 1 2,3
1: Output delay 3: Preemption delay
2: Link delay 4: Processing delay
5: Queuing delay
Figure 1: Timing model for DetNet or TSN
In Figure 1, we see two DetNet relay nodes (typically, bridges or
routers), with a wired link between them. In this model, the only
queues we deal with explicitly are attached to the output port; other
queues are modeled as variations in the other delay times. (E.g., an
input queue could be modeled as either a variation in the link delay
[2] or the processing delay [4].) There are five delays that a
packet can experience from hop to hop.
1. Output delay
The time taken from the selection of a packet for output from a
queue to the transmission of the first bit of the packet on the
physical link. If the queue is directly attached to the physical
port, output delay can be a constant. But, in many
implementations, the queuing mechanism in a forwarding ASIC is
separated from a multi-port MAC/PHY, in a second ASIC, by a
multiplexed connection. This causes variations in the output
delay that are hard for the forwarding node to predict or control.
1. Link delay
The time taken from the transmission of the first bit of the
packet to the reception of the last bit, assuming that the
transmission is not suspended by a preemption event. This delay
has two components, the first-bit-out to first-bit-in delay and
the first-bit-in to last-bit-in delay that varies with packet
size. The former is typically measured by the Precision Time
Protocol and is constant (see [I-D.ietf-detnet-architecture]).
However, a virtual "link" could exhibit a variable link delay.
3. Preemption delay
If the packet is interrupted (e.g. [IEEE8023br] preemption) in
order to transmit another packet or packets, an arbitrary delay
can result.
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4. Processing delay
This delay covers the time from the reception of the last bit of
the packet to that packet being eligible, if there were no other
packets in the queue, for selection for output. This delay can be
variable, and depends on the details of the operation of the
forwarding node.
5. Queuing delay
This is the time spent from the insertion of the packet into a
queue until the packet is selected for output on the next link.
We assume that this time is calculable based on the details of the
queuing mechanism and the sum of the variability in delay times
1-4.
Not shown in Figure 1 are the other output queues that we presume are
also attached to that same output port as the queue shown, and
against which this shown queue competes for transmission
opportunities.
The initial and final measurement point in this analysis (that is,
the definition of a "hop") is the point at which a packet is selected
for output. In general, any queue selection method that is suitable
for use in a DetNet network includes a detailed specification as to
exactly when packets are selected for transmission. Any variations
in any of the delay times 1-4 result in a need for additional buffers
in the queue. If all delays 1-4 are constant, then any variation in
the time at which packets are inserted into a queue depends entirely
on the timing of packet selection in the previous node. If the
delays 1-4 are not constant, then additional buffers are required in
the queue to absorb these variations. Thus:
o Variations in output delay (1) require buffers to absorb that
variation in the next hop, so the output delay variations of the
previous hop (on each input port) must be known in order to
calculate the buffer space required on this hop.
o Variations in processing delay (4) require additional output
buffers in the queues of that same Detnet relay node. Depending
on the details of the queueing delay (5) calculations, these
variations need not be visible outside the DetNet relay node.
4.2. Achieving zero congestion loss
When the input rate to an output queue exceeds the output rate for a
sufficient length of time, the queue must overflow. This is
congestion loss, and this is what deterministic networking seeks to
avoid.
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Imagine a completely saturated DetNet network, in which all is part
of some number of DetNet flows, and 100% of each link's bandwidth is
allocated to some number of DetNet Flows using that link. Every
source is transmitting at exactly its allotted rate. The DetNet
flows traverse the network in all directions; no two DetNet flows
take exactly the same path through the network. Imagine that there
are no variations in the output delay (1), link delay (2), and
processing delay (4), and there is no preemption delay (3).
Imagine now that one DetNet flow, DetNet flow A, stops. On some
output port through which DetNet flow A was passing, when the
transmission opportunity for one of DetNet flow A's packets comes up,
the DetNet relay node must either output nothing, or output a packet
belonging to some other DetNet flow B. If it outputs a packet from
DetNet flow B, then in the long term, it is exceeding the normal rate
for DetNet flow B, and runs the risk of overflowing the queues for
DetNet flow B in the next hop. With sufficient analysis, it may be
possible to determine the limits for how much excess data in DetNet
flow B, or DetNet flow C, from this and from other ports feeding the
next hop, can be accommodated before causing an overflow.
However, this analysis is very difficult. DetNet avoids the analysis
by transmitting nothing (or transmitting a non-DetNet packet) when it
has nothing to transmit for a given DetNet flow. This leads to
DetNet making the following requirement for DetNet relay nodes:
For every DetNet flow traversing a DetNet relay node, sufficient data
is buffered in that a DetNet relay node to ensure that a transmission
opportunity for that DetNet flow is never missed, unless the source
of the DetNet flow slows or stops. That is, for every DetNet flow,
over some finite time scale, the input rate equals the output rate.
5. Queuing model
5.1. Queuing data model
Sophisticated QoS mechanisms are available in Layer 3 (L3), see,
e.g., [RFC7806] for an overview. In general, we assume that "Layer
3" queues, shapers, meters, etc., are instantiated hierarchically
above the "Layer 2" queuing mechanisms, among which packets compete
for opportunities to be transmitted on a physical (or sometimes,
logical) medium. These "Layer 2 queuing mechanisms" are not the
province solely of bridges; they are an essential part of any DetNet
relay node. As illustrated by numerous implementation examples, the
"Layer 3" some of mechanisms described in documents such as [RFC7806]
are often integrated, in an implementation, with the "Layer 2"
mechanisms also implemented in the same system. An integrated model
is needed in order to successfully predict the interactions among the
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different queuing mechanisms needed in a network carrying both DetNet
flows and non-DetNet flows. See Section 6 for a more complete
discussion of the expanded model.
Figure 2 shows the (very simple) model for the flow of packets
through the queues of an IEEE 802.1Q bridge. Packets are assigned to
a class of service. The classes of service are mapped to some number
of physical FIFO queues. IEEE 802.1Q allows a maximum of 8 classes
of service, but it is more common to implement 2 or 4 queues on most
ports.
|
+--------------V---------------+
| Class of Service Assignment |
+--+-------+---------------+---+
| | |
+--V--+ +--V--+ +--V--+
|Class| |Class| |Class|
| 0 | | 1 | . . . | n |
|queue| |queue| |queue|
+--+--+ +--+--+ +--+--+
| | |
+--V-------V---------------V--+
| Transmission selection |
+--------------+--------------+
|
V
Figure 2: IEEE 802.1Q Queuing Model: Data flow
Some relevant mechanisms are hidden in this figure, and are performed
in the "Class n queue" box:
o Discarding packets because a queue is full.
o Discarding packets marked "yellow" by a metering function, in
preference to discarding "green" packets.
The Class of Service Assignment function can be quite complex, since
the introduction of [IEEE802.1Qci]. In addition to the Layer 2
priority expressed in the 802.1Q VLAN tag, a bridge can utilize any
of the following information to assign a packet to a particular class
of service (queue):
o Input port.
o Selector based on a rotating schedule that starts at regular,
time-synchronized intervals and has nanosecond precision.
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o MAC addresses, VLAN ID, IP addresses, Layer 4 port numbers, DSCP.
(Work items expected to add MPC and other indicators.)
o The Class of Service Assignment function can contain metering and
policing functions.
The "Transmission selection" function decides which queue is to
transfer its oldest packet to the output port when a transmission
opportunity arises.
5.2. Queuing Data Model with Preemption
Figure 2 must be modified if the output port supports preemption
([IEEE8021Qbu] and [IEEE8023br]). This modification is shown in
Figure 3.
|
+------------------------------V------------------------------+
| Class of Service Assignment |
+--+-------+-------+-------+-------+-------+-------+-------+--+
| | | | | | | |
+--V--+ +--V--+ +--V--+ +--V--+ +--V--+ +--V--+ +--V--+ +--V--+
|Class| |Class| |Class| |Class| |Class| |Class| |Class| |Class|
| a | | b | | c | | d | | e | | f | | g | | h |
|queue| |queue| |queue| |queue| |queue| |queue| |queue| |queue|
+--+--+ +--+--+ +--+--+ +--+--+ +--+--+ +--+--+ +--+--+ +--+--+
| | | +-+ | | | |
| | | | | | | |
+--V-------V-------V------+ +V-----V-------V-------V-------V--+
| Interrupted xmit select | | Preempting xmit select | 802.1
+-------------+-----------+ +----------------+----------------+
| | ======
+-------------V-----------+ +----------------V----------------+
| Preemptible MAC | | Express MAC | 802.3
+--------+----------------+ +----------------+----------------+
| |
+--------V-----------------------------------V----------------+
| MAC merge sublayer |
+--------------------------+----------------------------------+
|
+--------------------------V----------------------------------+
| PHY (unaware of preemption) |
+--------------------------+----------------------------------+
|
V
Figure 3: IEEE 802.1Q Queuing Model: Data flow with preemption
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From Figure 3, we can see that, in the IEEE 802 model, the preemption
feature is modeled as consisting of two MAC/PHY stacks, one for
packets that can be interrupted, and one for packets that can
interrupt the interruptible packets. The Class of Service (queue)
determines which packets are which. In Figure 3, the classes of
service are marked "a, b, ..." instead of with numbers, in order to
avoid any implication about which numeric Layer 2 priority values
correspond to preemptible or preempting queues. Although it shows
three queues going to the preemptible MAC/PHY, any assignment is
possible.
5.3. Transmission Selection Model
In Figure 4, we expand the "Transmission selection" function of
Figure 3.
Figure 4 does NOT show the data path. It shows an example of a
configuration of the IEEE 802.1Q transmission selection box shown in
Figure 2 and Figure 3. Each queue m presents a "Class m Ready"
signal. These signals go through various logic, filters, and state
machines, until a single queue's "not empty" signal is chosen for
presentation to the underlying MAC/PHY. When the MAC/PHY is ready to
take another output packet, then a packet is selected from the one
queue (if any) whose signal manages to pass all the way through the
transmission selection function.
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+-----+ +-----+ +-----+ +-----+ +-----+ +-----+ +-----+ +-----+
|Class| |Class| |Class| |Class| |Class| |Class| |Class| |Class|
| 1 | | 0 | | 4 | | 5 | | 6 | | 7 | | 2 | | 3 |
|Ready| |Ready| |Ready| |Ready| |Ready| |Ready| |Ready| |Ready|
+--+--+ +--+--+ +--+--+ +-XXX-+ +--+--+ +--+--+ +--+--+ +--+--+
| | | | | | |
| +--V--+ +--V--+ +--+--+ +--V--+ | +--V--+ +--V--+
| |Prio.| |Prio.| |Prio.| |Prio.| | |Sha- | |Sha- |
| | 0 | | 4 | | 5 | | 6 | | | per| | per|
| | PFC | | PFC | | PFC | | PFC | | | A | | B |
| +--+--+ +--+--+ +-XXX-+ +-XXX-+ | +--+--+ +-XXX-+
| | | | |
+--V--+ +--V--+ +--V--+ +--+--+ +--+--+ +--V--+ +--V--+ +--+--+
|Time | |Time | |Time | |Time | |Time | |Time | |Time | |Time |
| Gate| | Gate| | Gate| | Gate| | Gate| | Gate| | Gate| | Gate|
| 1 | | 0 | | 4 | | 5 | | 6 | | 7 | | 2 | | 3 |
+--+--+ +-XXX-+ +--+--+ +--+--+ +-XXX-+ +--+--+ +-XXX-+ +--+--+
| | |
+--V-------+-------V-------+--+ |
|802.1Q Enhanced Transmission | |
| Selection (ETS) = Weighted | |
| Fair Queuing (WFQ) | |
+--+-------+------XXX------+--+ |
| |
+--V-------+-------+-------+-------+-------V-------+-------+--+
| Strict Priority selection (rightmost first) |
+-XXX------+-------+-------+-------+-------+-------+-------+--+
|
V
Figure 4: 802.1Q Transmission Selection
The following explanatory notes apply to Figure 4
o The numbers in the "Class n Ready" boxes are the values of the
Layer 2 priority that are assigned to that Class of Service in
this example. The rightmost CoS is the most important, the
leftmost the least. Classes 2 and 3 are made the most important,
because they carry DetNet flows. It is all right to make them
more important than the priority 7 queue, which typically carries
critical network control protocols such as spanning tree or IS-IS,
because the shaper ensures that the highest priority best-effort
queue (7) will get reasonable access to the MAC/PHY. Note that
Class 5 has no Ready signal, indicating that that queue is empty.
o Below the Class Ready signals are shown the Priority Flow Control
gates (IEEE Std 802.1Qbb-2011 Priority-based Flow Control, now
[IEEE8021Q] clause 36) on Classes of Service 1, 0, 4, and 5, and
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two 802.1Q shapers, A and B. Perhaps shaper A conforms to the
IEEE Std 802.1Qav-2009 (now [IEEE8021Q] clause 34) credit-based
shaper, and shaper B conforms to [IEEE8021Qcr] Asynchronous
Traffic Shaper. Any given Class of Service can have either a PFC
function or a shaper, but not both.
o Next are the IEEE Std 802.1Qbv time gates ([IEEE8021Qbv]). Each
one of the 8 Classes of Service has a time gate. The gates are
controlled by a repeating schedule that restarts periodically, and
can be programmed to turn any combination of gates on or off with
nanosecond precision. (Although the implementation is not
necessarily that accurate.)
o Following the time gates, any number of Classes of Service can be
linked to one ore more instances of the Enhanced Transmission
Selection function. This does weighted fair queuing among the
members of its group.
o A final selection of the one queue to be selected for output is
made by strict priority. Note that the priority is determined not
by the Layer 2 priority, but by the Class of Service.
o An "XXX" in the lower margin of a box (e.g. "Prio. 5 PFC"
indicates that the box has blocked the "Class n Ready" signal.
o IEEE 802.1Qch Cyclic Queuing and Forwarding [IEEE802.1Qch] is
accomplished using two or three queues (e.g. 2 and 3 in the
figure), using sophisticated time-based schedules in the Class of
Service Assignment function, and using the IEEE 802.1Qbv time
gates [IEEE8021Qbv] to swap between the output buffers.
6. Extending the queuing model
6.1. Complex delay models
Using the model of Section 4, we can model any system, even one that
is very complex, including separate line cards, MAC/PHY modules, mid-
planes, backplanes, control/forwarding boards, etc. However, in a
complex case, the variations in the processing delay (4) may become
so large as to make any latency or buffer requirement analysis
relatively useless.
If a DetNet node is sufficiently complex that simply assigning a
minimum and maximum to the some delay (typically, the processing
delay, 4) results in insufficiently accurate computations for latency
or buffer requirements, the DetNet node can be modeled as a
federation of DetNet relay nodes, each conforming to the model.
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In the simplest example, system with input queues on each port could
be modeled having a two-port DetNet relay node inserted into each
input port, each with some number of output queues (which model the
input queues).
6.2. Extending the 802.1Q model to routers
Extending the models described in Section 5 to routers requires a
number of steps:
1. The Class of Service Assignment function of Figure 2 needs
extension to the DetNet flow identification techniques use in
[I-D.ietf-detnet-dp-alt].
2. Some applications will require more than 8 Classes of Service
(queues).
3. The Layer 3 queues, such as are defined in [RFC7806], must be
integrated with the 802.1Q queues. In some cases, this means
identifying an [RFC7806] queue with an 802.1Q CoS queue, and
having it compete with the other queues as shown in Figure 4. In
other cases, the [RFC7806] queues may form a unit, as in Figure 2
that is separate from any specific port, and feeds a forwarding
engine. Alternatively, some number of [RFC7806] queues can feed
one of the Figure 2 queues.
A QoS architecture integrating both Layer 3 and Layer 2 features is
necessary to exploit the benefits provided by the different layers if
a DetNet network includes link(s) or sub-network(s) equipped with TSN
features. For instance, it can be crucial for a time-critical DetNet
flow to leverage TSN features in a Layer 2 sub-network in order to
meet the DetNet flow's requirements, which may be spoiled otherwise.
Figure 5 provides a theoretical illustration for the integration of
the Layer 3 and Layer 2 QoS architecture. The figure only shows the
queuing after the routing decision. The figure also illustrates
potential implementation dependent borders (Brdr). The borders shown
in the figure are critical in the sense that the high priority DetNet
flows may, in some implementations, have to be transferred via a
different Service Access Points (SAPs) through these borders than the
low priority (background) flows. Having a single SAP for these very
different traffic types may result in possible QoS degradation for
the DetNet flows because packets of other flows could delay the
transmission of DetNet packets. For instance, different SAPs are
needed for the DetNet flows and other flows when they get to Layer 3
queuing after the routing decision via Brdr-d. Furthermore, a
different SAP may be needed for DetNet packets than other packets
when they get to Layer 2 queuing from Layer 3 queuing via Brdr-c.
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Certainly, in the 802.1/802.3 model, different SAPs are needed for
the express and for the preemptible frames when they get to the MAC
layer from Layer 2 queuing via Brdr-b, which is provided by the IEEE
802.1Q architecture as shown in Figure 3. It depends on the
implementation whether or not Brdr-a exists.
|
+---------------V-----------+
| Forwarding |
+--------+----------+--+----+
| | | === Brdr-d
+--------V--------+ | |
| CoS Assignment | | |
+-----------------+ | |
|Que-|Que-|..|Que-| | | Layer 3 queuing
| ue | ue |..| ue | | | and shaping
+-----------------+ | | (optional)
| Xmit selection | | |
+--------+----+---+ | |
| | | | === Brdr-c
+-V----V-----V--V-+
| CoS Assignment |
+-----------------+ Layer 2 queuing
|Que-|Que-|..|Que-| and shapng
| ue | ue |..| ue | (always present)
+-----------------+
| Xmit selection |
+--+-----------+--+
| | === Brdr-b
+------V----+ +---V-------+
|Preemptible| | Express |
| MAC | | MAC |
+------+----+ +----+------+
| | === Brdr-a
+------V------------V------+
| PHY |
+------------+-------------+
|
V
Figure 5: Combined L2/L3 Queueing Data Model
7. References
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7.1. Normative References
[I-D.ietf-detnet-architecture]
Finn, N. and P. Thubert, "Deterministic Networking
Architecture", draft-ietf-detnet-architecture-00 (work in
progress), September 2016.
[I-D.ietf-detnet-dp-alt]
Korhonen, J., Farkas, J., Mirsky, G., Thubert, P.,
Zhuangyan, Z., and L. Berger, "DetNet Data Plane Protocol
and Solution Alternatives", draft-ietf-detnet-dp-alt-00
(work in progress), October 2016.
[I-D.ietf-detnet-use-cases]
Grossman, E., Gunther, C., Thubert, P., Wetterwald, P.,
Raymond, J., Korhonen, J., Kaneko, Y., Das, S., Zha, Y.,
Varga, B., Farkas, J., Goetz, F., Schmitt, J., Vilajosana,
X., Mahmoodi, T., Spirou, S., Vizarreta, P., Huang, D.,
Geng, X., Dujovne, D., and M. Seewald, "Deterministic
Networking Use Cases", draft-ietf-detnet-use-cases-13
(work in progress), September 2017.
[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>.
[RFC2212] Shenker, S., Partridge, C., and R. Guerin, "Specification
of Guaranteed Quality of Service", RFC 2212,
DOI 10.17487/RFC2212, September 1997,
<https://www.rfc-editor.org/info/rfc2212>.
[RFC4364] Rosen, E. and Y. Rekhter, "BGP/MPLS IP Virtual Private
Networks (VPNs)", RFC 4364, DOI 10.17487/RFC4364, February
2006, <https://www.rfc-editor.org/info/rfc4364>.
[RFC6658] Bryant, S., Ed., Martini, L., Swallow, G., and A. Malis,
"Packet Pseudowire Encapsulation over an MPLS PSN",
RFC 6658, DOI 10.17487/RFC6658, July 2012,
<https://www.rfc-editor.org/info/rfc6658>.
[RFC7806] Baker, F. and R. Pan, "On Queuing, Marking, and Dropping",
RFC 7806, DOI 10.17487/RFC7806, April 2016,
<https://www.rfc-editor.org/info/rfc7806>.
Finn, et al. Expires May 3, 2018 [Page 14]
Internet-Draft DetNet Bounded Latency October 2017
7.2. Informative References
[IEEE802.1Qch]
IEEE, "IEEE Std 802.1Qch-2017 IEEE Standard for Local and
metropolitan area networks - Bridges and Bridged Networks
Amendment 29: Cyclic Queuing and Forwarding (amendment to
802.1Q-2014)", 2017,
<http://www.ieee802.org/1/files/private/ch-drafts/>.
[IEEE802.1Qci]
IEEE, "IEEE Std 802.1Qci-2017 IEEE Standard for Local and
metropolitan area networks - Bridges and Bridged Networks
- Amendment 30: Per-Stream Filtering and Policing", 2017,
<http://www.ieee802.org/1/files/private/ci-drafts/>.
[IEEE8021Q]
IEEE 802.1, "IEEE Std 802.1Q-2014: IEEE Standard for Local
and metropolitan area networks - Bridges and Bridged
Networks", 2014, <http://standards.ieee.org/getieee802/
download/802-1Q-2014.pdf>.
[IEEE8021Qbu]
IEEE, "IEEE Std 802.1Qbu-2016 IEEE Standard for Local and
metropolitan area networks - Bridges and Bridged Networks
- Amendment 26: Frame Preemption", 2016,
<http://standards.ieee.org/getieee802/
download/802.1Qbu-2016.zip>.
[IEEE8021Qbv]
IEEE 802.1, "IEEE Std 802.1Qbv-2015: IEEE Standard for
Local and metropolitan area networks - Bridges and Bridged
Networks - Amendment 25: Enhancements for Scheduled
Traffic", 2015, <http://standards.ieee.org/getieee802/
download/802.1Qbv-2015.zip>.
[IEEE8021Qcr]
IEEE 802.1, "IEEE P802.1Qcr: IEEE Draft Standard for Local
and metropolitan area networks - Bridges and Bridged
Networks - Amendment: Asynchronous Traffic Shaping", 2017,
<http://www.ieee802.org/1/files/private/cr-drafts/>.
[IEEE8021TSN]
IEEE 802.1, "IEEE 802.1 Time-Sensitive Networking (TSN)
Task Group", <http://www.ieee802.org/1/>.
Finn, et al. Expires May 3, 2018 [Page 15]
Internet-Draft DetNet Bounded Latency October 2017
[IEEE8023]
IEEE 802.3, "IEEE Std 802.3-2015: IEEE Standard for Local
and metropolitan area networks - Ethernet", 2015,
<http://standards.ieee.org/getieee802/
download/802.3-2015.zip>.
[IEEE8023br]
IEEE 802.3, "IEEE Std 802.3br-2016: IEEE Standard for
Local and metropolitan area networks - Ethernet -
Amendment 5: Specification and Management Parameters for
Interspersing Express Traffic", 2016,
<http://standards.ieee.org/getieee802/
download/802.3br-2016.pdf>.
Authors' Addresses
Norman Finn
Huawei Technologies Co. Ltd
3101 Rio Way
Spring Valley, California 91977
US
Phone: +1 925 980 6430
Email: norman.finn@mail01.huawei.com
Balazs Varga
Ericsson
Konyves Kalman krt. 11/B
Budapest 1097
Hungary
Email: balazs.a.varga@ericsson.com
Janos Farkas
Ericsson
Konyves Kalman krt. 11/B
Budapest 1097
Hungary
Email: janos.farkas@ericsson.com
Finn, et al. Expires May 3, 2018 [Page 16]
