Internet DRAFT - draft-dong-panet-requirement
draft-dong-panet-requirement
Network Working Group J. Dong
Internet-Draft M. Zhang
Intended status: Informational Huawei Technologies
Expires: April 19, 2014 B. Zhang
The University of Arizona
M. Boucadair
France Telecom
October 16, 2013
Requirements for Power Aware Network
draft-dong-panet-requirement-02
Abstract
Energy consumption of networks is rising fast, which results in the
increase of network operational costs. There are emerging demands
from operators for power-aware networking (PANET) which could
adaptively reduce the network energy consumption when possible. This
document presents the requirements which should be considered in
building a power aware network.
Requirements Language
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 RFC 2119 [RFC2119].
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
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material or to cite them other than as "work in progress."
This Internet-Draft will expire on April 19, 2014.
Copyright Notice
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Internet-Draft PANET Requirement October 2013
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Requirements on Network Elements . . . . . . . . . . . . . . 3
3. Requirements on the Whole Network . . . . . . . . . . . . . . 3
4. Requirements on Network Control Plane . . . . . . . . . . . . 5
5. Requirements on Management Plane . . . . . . . . . . . . . . 5
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6
7. Security Considerations . . . . . . . . . . . . . . . . . . . 6
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 6
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 6
9.1. Normative References . . . . . . . . . . . . . . . . . . 6
9.2. Informative References . . . . . . . . . . . . . . . . . 6
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 7
1. Introduction
With the increase of network services and exponential growth of
traffic volume, the network operators are expanding their
infrastructures with more high-capacity, full-featured network
devices, which also leads to the increase of network energy
consumption. Besides, today's service provider networks are mostly
designed for high performance and reliability, without much
consideration of energy efficiency. These networks usually have
redundant routers and links, over-provisioned link capacity, and
multiple paths for load-balancing and protection, which make the
networks far from energy efficient. As energy price continues to
rise, the increasing network energy consumption becomes a significant
portion of the network operational costs. The energy consumption
problem in service provider networks is detailed in
[I-D.zhang-panet-problem-statement]. Some use cases of reducing
network energy consumption are described in
[I-D.zhang-panet-use-cases].
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While energy consumption has become an important issue, network
operators are very cautious about energy conservation solutions due
to the concerns about the potential impacts on the network
performance and resiliency.
This document presents a set of requirements for building a Power
Aware NETwork (PANET) while meeting operators' requirements on
performance and resiliency.
2. Requirements on Network Elements
Today's network elements are mostly designed for high throughput and
availability. With the increase of throughput capacity, energy
consumption of network element is also rising accordingly. Since
most of time the network elements in the network would not work in
the full loaded state, if the energy consumption of network elements
could be proportional to the carried traffic load, energy
conservation could be achieved. Typically after a network element is
turned on, the base energy consumption is relatively high, and the
energy consumption of the device does not vary a lot from zero load
state to full loaded state. While there has been a lot of efforts
aiming at making the energy consumption of network device
proportional to the load it carries, it is not quite easy for the
network elements getting to this stage in the near term.
Thus for near term energy saving, In practical the network elements
should meet the following requirements:
o Network elements should support a set of energy saving modes (e.g.
sleeping mode, etc. as defined in IETF EMAN working group). The
energy consumption under energy saving modes should be much lower
than that under the normal mode.
o Network elements should support the report of energy consumption
and state information.
o The transition between different energy modes SHOULD not cost a
lot of energy, otherwise there will not be no much benefit of
transiting between different energy modes.
o Network elements should support the transition between different
energy modes within acceptable time period, e.g. subsecond.
o Network elements should support some approach of reducing the
packet loss during the transition of energy modes.
3. Requirements on the Whole Network
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While energy awareness and conservation of individual network element
is fundamental, currently there are many limits in reducing the
energy consumption at network element level. Besides, different from
terminal devices like PC and mobile phones, network elements usually
cannot be shut down arbitrarily as this may affect the services
carried in the network. Thus mechanisms which could reduce the
energy consumption from the whole network point of view should also
be considered.
Most of the existing networks are over-provisioned for better service
performance and redundancy, which means they are not energy efficient
by default. In order to save energy, the entire network should
become power aware, then it can make appropriate decisions to save
energy when possible. Since in most time the network does not carry
the peak traffic volume, which means there is chance for the network
to coordinate network elements and create opportunity for some of the
network elements to enter energy saving modes. Meanwhile, reducing
energy consumption of the network should not undermine the
performance of services carried by the network.
For energy conservation of the whole network, the network should meet
the following requirements:
o The network should try to keep all the active network elements
with a reasonable utilization rate, network elements with low
utilization should be informed to enter energy saving modes. For
example, the network elements with utilization lower than specific
threshold may be put into low rate mode to reduce energy
consumption, or the traffic carried by these network elements may
be migrated to other paths such that these network elements could
be put into sleeping mode.
o With energy conservation, the network should retain enough network
availability and resiliency against node and link failures. In
other words, the redundancy of the network should be kept at a
reasonable level, e.g. 2-connected.
o Energy saving of the network should not induce increase of latency
nor induce traffic loss which exceed the tolerance of the services
in the network. QoS metrics such as end-to-end delay, loss and
jitter should be kept at a desired level.
o The network should reserve enough spare capacity or be able to
react quickly to absorb traffic spikes in order to minimize packet
loss due to congestions.
o The network stability should be preserved. Particularly, traffic
oscillation should be avoided.
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o Energy saving should not conflict with other policies (e.g.
performance at the highest priority) in the network.
4. Requirements on Network Control Plane
Most of the existing network control protocols do not take energy
awareness or efficiency into consideration, and some protocols may
not work properly when some of the network elements in the network
are in energy saving modes. For example, when a network link is put
into sleeping mode, the protocols run on this link may be impacted.
For energy saving of the whole network, control plane should meet the
following requirements:
o Control plane should be able to work properly when some of the
network elements are in energy saving mode.
o Control plane should support the advertisement of energy related
information (e.g. current energy saving mode) of network elements
in the network.
o Control plane should be able to coordinate the energy saving
operations of network elements to achieve the overall network
energy saving.
o Control plane should be able to maximize the opportunity for
network elements to enter the energy saving modes.
o Control plane should be aware of the network elements in energy
saving modes, and should be able to calculate available paths
(e.g. which do not traverse the network elements in sleeping
mode).
o Control plane should be able to calculate the path set for all
services carried by the network in a way that energy conservation
of the whole network is achieved.
Some considerations on control plane when using energy saving
mechanism are also specified in [I-D.retana-rtgwg-eacp].
5. Requirements on Management Plane
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Management plane would also be necessary for building a power aware
network. IETF EMAN working group is working on the requirements
[I-D.ietf-eman-requirements]and mechanisms for energy management.
Such management requirements include identification of energy-managed
devices and their components, monitoring of a series of power states
and power properties. It may further includes controlling of the
power supply and power states of the managed devices.
6. IANA Considerations
This document makes no request of IANA.
Note to RFC Editor: this section may be removed on publication as an
RFC.
7. Security Considerations
TBD
8. Acknowledgements
TBD
9. References
9.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
9.2. Informative References
[I-D.ietf-eman-requirements]
Quittek, J., Chandramouli, M., Winter, R., Dietz, T., and
B. Claise, "Requirements for Energy Management", draft-
ietf-eman-requirements-14 (work in progress), May 2013.
[I-D.retana-rtgwg-eacp]
Retana, A., White, R., and M. Paul, "A Framework and
Requirements for Energy Aware Control Planes", draft-
retana-rtgwg-eacp-01 (work in progress), February 2013.
[I-D.zhang-panet-problem-statement]
Zhang, B., Shi, J., Dong, J., Zhang, M., and M. Boucadair,
"Power-Aware Networks (PANET): Problem Statement", draft-
zhang-panet-problem-statement-03 (work in progress),
October 2013.
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[I-D.zhang-panet-use-cases]
Zhang, M., Dong, J., Zhang, B., and B. Khargharia, "Use
Cases for Power-Aware Networks", draft-zhang-panet-use-
cases-03 (work in progress), October 2013.
Authors' Addresses
Jie Dong
Huawei Technologies
Beijing 100095
China
Email: jie.dong@huawei.com
Mingui Zhang
Huawei Technologies
Beijing 100095
China
Email: zhangmingui@huawei.com
Beichuan Zhang
The University of Arizona
USA
Email: bzhang@cs.arizona.edu
Mohamed Boucadair
France Telecom
France
Email: mohamed.boucadair@orange.com
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