wdiff rfc8625.original rfc8625.txt

Network Working Group
Internet Engineering Task Force (IETF) H. Long, Long
Request for Comments: 8625 M. Ye
Internet Draft Ye, Ed.
Category: Standards Track Huawei Technologies Co., Ltd
Intended status: Standards Track Ltd.
ISSN: 2070-1721 G. Mirsky Mirsky, Ed.
ZTE
A.D'Alessandro
A. D'Alessandro
Telecom Italia S.p.A
H. Shah
Ciena
Expires: November 2019 May 5,
August 2019

Ethernet Traffic Parameters with Availability Information
draft-ietf-ccamp-rsvp-te-bandwidth-availability-16.txt

Abstract

A packet switching packet-switching network may contain links with variable
bandwidth, e.g., copper, radio, etc. bandwidths
(e.g., copper and radio). The bandwidth of such links is sensitive
to the external environment (e.g., climate). Availability is
typically used for describing to describe these links when doing network planning.
This document introduces an optional Bandwidth Availability TLV in Resource ReSerVation Protocol - Traffic Engineer
(RSVP-TE)
RSVP-TE signaling. This extension can be used to set up a
Generalized Multi-Protocol Label Switching (GMPLS) GMPLS
Label Switched Path (LSP) in conjunction with the Ethernet
SENDER_TSPEC object.

Status of this This Memo

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https://www.rfc-editor.org/info/rfc8625.

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Table of Contents

1. Introduction ................................................ 3 ....................................................3
1.1. Conventions Used in This Document ..........................4
2. Overview .................................................... 4 ........................................................4
3. Extension to RSVP-TE Signaling............................... 5 Signaling ..................................5
3.1. Bandwidth Availability TLV.............................. 5 TLV .................................5
3.2. Signaling Process....................................... 6 Process ..........................................6
4. Security Considerations...................................... 7 Considerations .........................................7
5. IANA Considerations ......................................... 7
5.1 Ethernet Sender TSpec TLVs ............................. 7 .............................................8
6. References .................................................. 8 ......................................................8
6.1. Normative References.................................... 8 References .......................................8
6.2. Informative References.................................. 9
7. Appendix: References .....................................9
Appendix A. Bandwidth Availability Example..................... 9
8. Example .......................11
Acknowledgments ............................................ 11

Conventions used in this document

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.

The following acronyms are used in this draft:

RSVP-TE Resource Reservation Protocol-Traffic Engineering

LSP Label Switched Path
SNR Signal-to-noise Ratio

TLV Type Length Value

LSA Link State Advertisement ...................................................13
Authors' Addresses ................................................13

1. Introduction

The RSVP-TE specification [RFC3209] and GMPLS extensions [RFC3473]
specify the signaling message message, including the bandwidth request for
setting up a Label Switched Path an LSP in a packet switching packet-switching network.

Some data communication technologies allow a seamless change of the
maximum physical bandwidth through a set of known discrete values.
The parameter availability [G.827], [F.1703], [G.827] [F.1703] [P.530] is often used to
describe the link capacity during network planning. The availability
is based on a time scale, which is a proportion of the operating time
that the requested bandwidth is ensured. A more detailed example on the of
bandwidth availability can be found in Appendix A. Assigning
different bandwidth availability classes to different types of
services over such kind of links with variable discrete bandwidth provides for a
more efficient planning of link capacity. To set up an LSP across
these links, bandwidth availability information is required for the
nodes to verify bandwidth satisfaction and make a bandwidth
reservation. The bandwidth availability information should be
inherited from the bandwidth availability requirements of the
services expected to be carried on the LSP. For example, voice
service usually needs "five nines" 99.999% bandwidth availability, while
non-real non-real-
time services may adequately perform at four 99.99% or three nines 99.9% bandwidth
availability. Since different service types may need different availabilities
availability guarantees, multiple <availability, bandwidth> pairs may
be required when signaling.

If the bandwidth availability requirement is not specified in the
signaling message, the bandwidth will likely be reserved as the
highest bandwidth availability. Suppose, for example, the bandwidth
with 99.999% availability of a link is 100 Mbps; Mbps, and the bandwidth
with 99.99% availability is 200 Mbps. When a video application makes
a request for 120 Mbps without a bandwidth availability requirement,
the system will consider the request as 120 Mbps with 99.999%
bandwidth availability, while the available bandwidth with 99.999%
bandwidth availability is only 100 Mbps, therefore Mbps. Therefore, the LSP path
cannot be set up. But, in fact, However, the video application doesn't need
99.999% bandwidth availability; 99.99% bandwidth availability is
enough. In this case, the LSP could be set up if the bandwidth
availability is also specified in the signaling message.

To fulfill an LSP setup by signaling in these scenarios, this
document specifies a Bandwidth Availability TLV. The Bandwidth
Availability TLV can be applicable to any kind of physical links link with
variable discrete bandwidth, such as microwave or DSL. Multiple
Bandwidth Availability TLVs TLVs, together with multiple Ethernet
Bandwidth Profiles Profile TLVs, can be carried by the Ethernet SENDER_TSPEC
object [RFC6003]. Since the Ethernet FLOWSPEC object has the same
format as the Ethernet SENDER_TSPEC object [RFC6003], the Bandwidth
Availability TLV can also be carried by the Ethernet FLOWSPEC object.

1.1. Conventions Used in This Document

The following acronyms are used in this document:

RSVP-TE Resource Reservation Protocol - Traffic Engineering

LSP Label Switched Path

SNR Signal-to-Noise Ratio

TLV Type-Length-Value

LSA Link State Advertisement

QAM Quadrature Amplitude Modulation

QPSK Quadrature Phase Shift Keying

2. Overview

A tunnel in a packet switching packet-switching network may span one or more links in
a network. To setup a Label Switched Path (LSP), set up an LSP, a node may collect link information which
that is advertised in a routing message, e.g., message (e.g., an OSPF TE LSA message,
message) by network nodes to obtain network topology information, and
it can then calculate an LSP route based on the network topology.
The calculated LSP route is signaled using a PATH/RESV message for setting to set
up the LSP.

In case that there is (are) link(s)

If a network contains one or more links with variable discrete bandwidth
in a network,
bandwidths, a <bandwidth, availability> requirement list should be
specified for an LSP at setup. Each <bandwidth, availability> pair
in the list means the listed bandwidth with specified availability is
required. The list could can be derived from the results of service
planning for the LSP.

A node which that has link(s) with variable discrete bandwidth attached
should contain a <bandwidth, availability> information list in its
OSPF TE LSA messages. The list provides the mapping between the link
nominal bandwidth and its availability level. This information can
then be used for path calculation by the node(s). The routing
extension for availability can be found in [RFC8330].

When a node initiates a PATH/RESV signaling to set up an LSP, the
PATH message should carry the <bandwidth, availability> requirement
list as a bandwidth request. Intermediate node(s) will allocate the
bandwidth resource resources for each availability requirement from the
remaining bandwidth with the corresponding availability. An error
message may be returned if any <bandwidth, availability> request
cannot be satisfied.

3. Extension to RSVP-TE Signaling

3.1. Bandwidth Availability TLV

A Bandwidth Availability TLV is defined as a TLV of the Ethernet
SENDER_TSPEC object [RFC6003] in this document. The Ethernet
SENDER_TSPEC object MAY include more than one Bandwidth Availability
TLV. The Bandwidth Availability TLV has the following format:

0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Index | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Availability |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Figure 1: Bandwidth Availability TLV

Type (2 octets): 0x04(suggested; TBD by IANA) 4

Length (2 octets): 0x0C. Indicates the length in bytes of the whole TLV
TLV, including the Type and Length fields, in fields. In this case case, the length
is 12 bytes.

Index (1 octet): When the Bandwidth Availability TLV is included, the
Ethernet Bandwidth Profile TLV MUST also be included. If there are
multiple bandwidth requirements present (in multiple Ethernet
Bandwidth Profile TLVs) and they have different availability
requirements, multiple Bandwidth Availability TLVs MUST be carried.
In such a case, the Bandwidth Availability TLV has a one to one one-to-one
correspondence with the Ethernet Bandwidth Profile TLV by having as both have
the same value of in the Index field. If all the bandwidth requirements
in the Ethernet Bandwidth Profile TLV have the same Availability availability
requirement, one Bandwidth Availability TLV SHOULD be carried. In
this case, the Index field is set to 0.

Reserved (3 octets): These bits SHOULD be set to zero when sent and
MUST be ignored when received.

Availability (4 octets): a A 32-bit floating-point number in binary
interchange format [IEEE754] describes the decimal value of the
availability requirement for this bandwidth request. The value MUST
be less than 1 and is usually expressed in the value as one of
0.99/0.999/0.9999/0.99999. the following
values: 0.99, 0.999, 0.9999, or 0.99999. The IEEE floating-point
number is used here to align with [RFC8330]. However when When representing
values higher than 0.999999, the floating-point number starts to
introduce errors in relation to intended precision. However However, in reality, 0.99999
is normally considered as the highest availability value (5 (which results
in 5 minutes of outage in a year) in a telecom
network, therefore network. Therefore,
the use of a floating-point number in for availability is acceptable.

3.2. Signaling Process

The source node initiates a PATH message message, which may carry a number of
bandwidth requests, including one or more Ethernet Bandwidth Profile
TLVs and one or more Bandwidth Availability TLVs. Each Ethernet
Bandwidth Profile TLV corresponds to an availability parameter in the
associated Bandwidth Availability TLV.

The

When the intermediate and destination nodes check whether they can
satisfy receive the PATH message,
the nodes compare the requested bandwidth requirements by comparing under each bandwidth
request inside availability
level in the SENDER_TSPEC objects objects, with the remaining link sub- bandwidth resource with respective
resources under a corresponding availability guarantee level on the a local link when link,
to check if they can meet the PATH message is received. bandwidth requirements.

o When all <bandwidth, availability> requirement requests can be
satisfied (the (that is, the requested bandwidth under each
availability parameter is smaller than or equal to the remaining
bandwidth under the corresponding availability parameter on its
local link), the node SHOULD reserve the bandwidth resource resources from
each remaining sub-bandwidth portion on its local link to set up
this LSP. Optionally, a higher availability bandwidth can be
allocated to a lower availability request when the lower
availability bandwidth cannot satisfy the request.

o When at least one <bandwidth, availability> requirement request
cannot be satisfied, the node SHOULD generate a PathErr message
with the error code "Admission Control Error" and the error value
"Requested Bandwidth Unavailable" (see [RFC2205]).

When two LSPs request bandwidth with the same availability
requirement, the contention MUST be resolved by comparing the node
IDs,
with where the LSP with the higher node ID being is assigned the
reservation. This is consistent with the general contention
resolution mechanism provided in section Section 4.2 of [RFC3471].

When a node does not support the Bandwidth Availability TLV, the node
should send a PathErr message with error code "Unknown Attributes
TLV", as specified in [RFC5420]. An LSP could also be set up in this
case if there's enough bandwidth (the (note that the availability level of
the reserved bandwidth is unknown). When a node receives Bandwidth
Availability TLVs with a mix of zero index and non-zero
index, indexes, the
message MUST be ignored and MUST NOT be propagated. When a node
receives Bandwidth Availability TLVs (non-zero index) with no
matching index value among the bandwidth-TLVs, Ethernet Bandwidth Profile TLVs, the
message MUST be ignored and MUST NOT be propagated. When a node
receives several <bandwidth, availability> pairs, but there are extra bandwidth-TLVs
without matching
Ethernet Bandwidth Profile TLVs that do not match the index of any Availability-TLV,
Bandwidth Availability TLV, the extra
bandwidth-TLVs Ethernet Bandwidth Profile TLVs
MUST be ignored and MUST NOT be propagated.

4. Security Considerations

This document defines a Bandwidth Availability TLV in RSVP-TE
signaling used in GMPLS networks. [RFC3945] notes that
authentication in GMPLS systems may use the authentication mechanisms
of the component protocols. [RFC5920] provides an overview of
security vulnerabilities and protection mechanisms for the GMPLS
control plane. Especially section In particular, Section 7.1.2 of [RFC5920] discusses
the control-plane protection with RSVP-TE by using general RSVP
security tools, limiting the impact of an attack on control-
plane control-plane
resources, and using authentication for RSVP messages. Moreover, the
GMPLS network is often considered to be a closed network such that
insertion, modification, or inspection of packets by an outside party
is not possible.

5. IANA Considerations

IANA maintains registries and sub-registries for RSVP-TE used by
GMPLS. IANA is requested to make allocations from these registries
as set out in the following sections.

5.1 Ethernet Sender TSpec TLVs

IANA maintains a registry of GMPLS parameters called the "Generalized
Multi-Protocol Label Switching (GMPLS) Signaling Parameters".

IANA has created a sub-registry called Parameters"
registry. This registry includes the "Ethernet Sender TSpec TLVs / TLVs/
Ethernet Flowspec TLVs" to contain subregistry that contains the TLV type values
for TLVs carried in the Ethernet SENDER_TSPEC object. The sub-registry needs
to be This
subregistry has been updated to include the Bandwidth Availability TLV which is
defined as follow. This document proposes a suggested value for the
Availability sub-TLV; it is requested that the suggested value be
granted by IANA.
TLV:

Type Description Reference

----- --------------------
---- ---------------------- ---------

0x04
4 Bandwidth Availability [This ID]

(Suggested; TBD by IANA)

The registration procedure for this registry is Standards Action as
defined in [RFC8126]. RFC 8625

6. References

6.1. Normative References

[IEEE754] IEEE, "IEEE Standard for Floating-Point Arithmetic",
IEEE 754, DOI 10.1109/IEEESTD.2008.4610935.

[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>.

[RFC2205] Braden, R., Ed., Zhang, L., Berson, S., Herzog, S., and
S.Jamin, S.
Jamin, "Resource ReSerVation Protocol (RSVP) - -- Version 1
Functional Specification", RFC 2205, DOI 10.17487/RFC2205,
September 1997. 1997, <https://www.rfc-editor.org/info/rfc2205>.

[RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan,
V.,and V.,
and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP
Tunnels", RFC 3209, DOI 10.17487/RFC3209, December 2001.

[RFC3473] 2001,
<https://www.rfc-editor.org/info/rfc3209>.

[RFC3471] Berger, L., Ed., "Generalized Multi-Protocol Label
Switching (GMPLS) Signaling Resource ReserVation Protocol-Traffic
Engineering (RSVP-TE) Extensions", Functional Description",
RFC 3473, 3471, DOI 10.17487/RFC3471, January 2003.

[RFC3471] 2003,
<https://www.rfc-editor.org/info/rfc3471>.

[RFC3473] Berger, L., Ed., "Generalized Multi-Protocol Label
Switching (GMPLS) Signaling Functional Description", Resource ReserVation Protocol-
Traffic Engineering (RSVP-TE) Extensions", RFC 3471, 3473,
DOI 10.17487/RFC3473, January 2003. 2003,
<https://www.rfc-editor.org/info/rfc3473>.

[RFC5420] Farrel, A., Ed., Papadimitriou, D., Vasseur Vasseur, JP., and Ayyangar
A., A.
Ayyangarps, "Encoding of Attributes for MPLS LSP
Establishment Using Resource Reservation Protocol Traffic
Engineering (RSVP-TE)", RFC 5420, DOI 10.17487/RFC5420,
February 2009. 2009, <https://www.rfc-editor.org/info/rfc5420>.

[RFC6003] Papadimitriou, D. D., "Ethernet Traffic Parameters",
RFC 6003, DOI 10.17487/RFC6003, October 2010. 2010,
<https://www.rfc-editor.org/info/rfc6003>.

[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, May 2017.

[IEEE754] IEEE, "IEEE Standard for Floating-Point Arithmetic",IEEE
754-2008, DOI 10.1109/IEEESTD.2008.4610935, 2008,
<http://standards.ieee.org/findstds/standard/754-
2008.html>. 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.

6.2. Informative References

[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", RFC 2119, March 1997.

[RFC8126] Cotton,M. and Leiba,B.,

[EN-302-217]
ETSI, "Fixed Radio Systems; Characteristics and Narten T., "Guidelines for
Writing an IANA Considerations Section in RFCs", RFC 8126,
June 2017.

[RFC3945] Mannie, E., "Generalized Multi-Protocol Label Switching
(GMPLS) Architecture", RFC 3945, October 2004.

[RFC5920] Fang, L., "Security Framework
requirements for MPLS point-to-point equipment and GMPLS
Networks", RFC 5920, July 2010.

[G.827] ITU-T Recommendation, "Availability performance parameters antennas;
Part 1: Overview and objectives for end-to-end international constant bit-
rate digital paths", September 2003. system-independent common
characteristics", ETSI EN 302 217-1, Version 3.1.1, May
2017.

[F.1703] ITU-R Recommendation, ITU-R, "Availability objectives for real digital fixed
wireless links used in 27 500 km hypothetical reference
paths and connections", ITU-R Recommendation F.1703-0,
January
2005. 2005, <https://www.itu.int/rec/R-REC-F.1703/en>.

[G.827] ITU-T, "Availability performance parameters and objectives
for end-to-end international constant bit-rate digital
paths", ITU-T Recommendation G.827, September 2003,
<https://www.itu.int/rec/T-REC-G.827/en>.

[P.530] ITU-R Recommendation," Propagation ITU-R, "Propagation data and prediction methods required
for the design of terrestrial line-of-
sight line-of-sight systems", February 2012

[EN 302 217] ETSI standard, "Fixed Radio Systems; Characteristics
and requirements
ITU-R Recommendation P.530-17, December 2017,
<https://www.itu.int/rec/R-REC-P.530/en>.

[RFC3945] Mannie, E., Ed., "Generalized Multi-Protocol Label
Switching (GMPLS) Architecture", RFC 3945,
DOI 10.17487/RFC3945, October 2004,
<https://www.rfc-editor.org/info/rfc3945>.

[RFC5920] Fang, L., Ed., "Security Framework for point-to-point equipment MPLS and
antennas", April 2009 GMPLS
Networks", RFC 5920, DOI 10.17487/RFC5920, July 2010,
<https://www.rfc-editor.org/info/rfc5920>.

[RFC8330] H., Long, M., H., Ye, M., Mirsky, G., Alessandro, D'Alessandro, A., and H.
Shah, H., "OSPF Traffic Engineering (OSPF-TE) Link
Availability Extension for Links with Variable Discrete
Bandwidth",
RFC8330, RFC 8330, DOI 10.17487/RFC8330, February 2018

7. Appendix: 2018,
<https://www.rfc-editor.org/info/rfc8330>.

Appendix A. Bandwidth Availability Example

In a mobile backhaul network, networks, microwave links are very popular for
providing connections of last hops. In case of To maintain link connectivity in
heavy rain conditions, to maintain the link connectivity, the microwave link may lower the modulation
level since moving to a lower modulation level provides for a lower Signal-to-Noise Ratio (SNR)
SNR requirement. This is called adaptive modulation "adaptive modulation" technology [EN 302 217].
[EN-302-217]. However, a lower modulation level also means a lower
link bandwidth. When a link bandwidth is reduced because of
modulation down-shifting, high-
priority downshifting, high-priority traffic can be maintained,
while lower-priority traffic is dropped. Similarly, copper links may
change their link bandwidth due to external interference.

Presuming

Presume that a link has three discrete bandwidth levels:

o The link bandwidth under modulation level 1, e.g., QPSK, 1 (e.g., QPSK) is 100
Mbps;
Mbps.

o The link bandwidth under modulation level 2, e.g., 16QAM, 2 (e.g., 16QAM) is 200
Mbps;
Mbps.

o The link bandwidth under modulation level 3, e.g., 256QAM, 3 (e.g., 256QAM) is 400
Mbps.

On a sunny day, the modulation level 3 can be used to achieve a 400 Mbps
link bandwidth.

A light

Light rain with a X mm/h rate triggers the system to change the
modulation level from level 3 to level 2, with the bandwidth changing
from 400 Mbps to 200 Mbps. The probability of X mm/h rain in the
local area is 52 minutes in a year. Then the dropped 200 Mbps
bandwidth has 99.99% availability.

A heavy

Heavy rain with a Y(Y>X) mm/h rate triggers the system to change the
modulation level from level 2 to level 1, with the bandwidth changing
from 200 Mbps to 100 Mbps. The probability of Y mm/h rain in the
local area is 26 minutes in a year. Then the dropped 100 Mbps
bandwidth has 99.995% availability.

For the 100M 100 Mbps bandwidth of the modulation level 1, only the extreme
weather condition conditions can cause the whole system to be unavailable,
which only happens for 5 minutes in a year. So the 100 Mbps
bandwidth of the modulation level 1 owns the availability of 99.999%.

There are discrete buckets per availability level. Under the worst
weather conditions, there's only 100 Mbps capacity and that's capacity, which is 99.999%
available. It's treated as effectively as "always available" since there's no way to do any better.
better availability is not possible. If the weather is bad but not
the worst weather, possible conditions, modulation level 2 can be used, which
gets an additional 100 Mbps bandwidth (i.e., 200 Mbps total), so there are total).
Therefore, 100 Mbps is in the 99.999% bucket bucket, and 100 Mbps is in the
99.995% bucket. In clear weather, modulate modulation level 3 can be used to
get 400 Mbps total, but that's only 200 Mbps more than at modulation
level 2, so the 99.99% bucket has that "extra" 200 Mbps, and the
other two buckets still have their 100 Mbps each.

Therefore, the maximum bandwidth is 400 Mbps. According to the
weather condition, the The sub-bandwidth and
its availability according to the weather conditions are shown as
follows:

Sub-bandwidth (Mbps) Availability
------------------ ------------

200 99.99%

100 99.995%

100 99.999%

Acknowledgments

The authors would like to thank Deborah Brungard, Khuzema Pithewan,
Lou Berger, Yuji Tochio, Dieter Beller, and Autumn Liu for their
comments on and contributions on to the document.

Authors' Addresses

Hao Long
Huawei Technologies Co., Ltd.
No.1899, Xiyuan Avenue, Hi-tech Western District
Chengdu 611731, P.R.China 611731
China

Phone: +86-18615778750
Email: longhao@huawei.com

Min Ye (editor)
Huawei Technologies Co., Ltd.
No.1899, Xiyuan Avenue, Hi-tech Western District
Chengdu 611731, P.R.China 611731
China

Email: amy.yemin@huawei.com

Greg Mirsky (editor)
ZTE

Email: gregimirsky@gmail.com

Alessandro D'Alessandro
Telecom Italia S.p.A

Email: alessandro.dalessandro@telecomitalia.it

Himanshu Shah
Ciena Corp.
3939 North First Street
San Jose, CA 95134
US
United States of America

Email: hshah@ciena.com