Internet DRAFT - draft-mjsraman-rtgwg-ospf-ldp-power-topo
draft-mjsraman-rtgwg-ospf-ldp-power-topo
RTGWG Working Group Shankar Raman
INTERNET-DRAFT Balaji Venkat Venkataswami
Intended Status: Experimental RFC Gaurav Raina
Expires: November 11, 2013 Vasan Srini
IIT Madras
May 10, 2013
Power Based Topologies in OSPF using LDP for label exchanges
draft-mjsraman-rtgwg-ospf-ldp-power-topo-00
Abstract
In this specification OSPF shortest path first computation is done
based on power ratios (consumed-power to available-bandwidth OR
available-bandwidth to available-bandwidth) assigned to links and
nodes such as Broadcast-Multi-Access networks that form part of the
topology in an area. When MPLS is deployed in the area (be it the
backbone or non-backbone area) LDP can be used to distribute a
disjoint set of labels for the power based topology. Flows some or
all of those that traverse the area can then be mapped either to the
regular shortest-path tree or the power based shortest-path tree.
This document specifies the proposal to construct and maintain such a
tree called the power based SPT.
Status of this Memo
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Copyright and License Notice
Copyright (c) 2013 IETF Trust and the persons identified as the
document authors. All rights reserved.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1 Terminology . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Methodology . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.0.1 Experimental results and their inferences . . . . . . . 8
2.1 Power Bias . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.1.1 Advertising Available POWER . . . . . . . . . . . . . . 8
2.2 ECMP links . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.3 Dampening the side effects of constant change . . . . . . . 9
2.4 Calculating power shortest paths in an Area . . . . . . . . 9
2.4.1 Power profiles of Routers and Switches and SPF
computation . . . . . . . . . . . . . . . . . . . . . . 10
2.4.1.3 Need to advertise both available power and
consumed power . . . . . . . . . . . . . . . . . . . 14
2.4.2 Power to Available Bandwidth ratio in a TLV . . . . . . 14
2.4.3 LDP Capability Parameter TLV for Power-SPF based label
exchanges . . . . . . . . . . . . . . . . . . . . . . . 16
2.4.4 When one peer says Power-SPF is fine but the other
doesnt . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.4.5 Mapping flows to the Power based SPT . . . . . . . . . . 16
3 Security Considerations . . . . . . . . . . . . . . . . . . . . 17
4 IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 17
5 References . . . . . . . . . . . . . . . . . . . . . . . . . . 17
5.1 Normative References . . . . . . . . . . . . . . . . . . . 17
5.2 Informative References . . . . . . . . . . . . . . . . . . 17
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 18
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1. Introduction
Estimates of power consumption for the Internet predict a 300%
increase, as access speeds increase from 10 Mbps to 100 Mbps [3],
[8]. Access speeds are likely to increase as new video, voice and
gaming devices get added to the Internet. Various approaches have
been proposed to reduce the power consumption of the Internet such as
designing low-power routers and switches, and optimizing the network
topology using traffic engineering methods [2].
Typically both Campus networks and Service Provider networks face
power saving challenges. It is even exacerbated in modern data
centers. In this document we propose a scheme that will apply to all
of these areas of interest.
In a Interior Gateway Protocol like OSPF (Open Shortest Path First)
the routes for networks and their specific next-hops are built from a
tree with the router that is involved in the calculation being the
root of the tree. Initially link-state database items are exchanged
prior to this Shortest Path First computation. Once the database
exchanges are complete then the weights assigned to links and
Broadcast Multi-Access (BMA) nodes are used to find the shortest path
from the said router to each destination advertised in the network
(through these database exchanges). It is proposed in this document
that the weights assigned to links and BMA nodes be determined by a
ratio of consumed-power-to-available-bandwidth or available-power to-
available bandwidth and be advertised along with the regular link and
BMA node metrics. Thus an alter-ego of the regular topology with
weights determined by the ratios mentioned are maintained. Once these
are maintained in each router for its area the shortest path
computation is done based on this power ratio based topology.
When LDP is used to distribute MPLS labels by a router in an area,
the router besides distributing its regular topology labels also
distributes labels for the power-shortest path tree computed using
the power ratios as link weights. This topology could be used to
assign some or all of the flows (if all then the power based
shortest-path tree becomes the default tree) passing through the area
to the routers which are more power efficient. Power profiles of
various routers is also discussed in this context in this document.
1.1 Terminology
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].
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The proposal we make in this document indicates ways to solve the
power reduction problem, by calculating a POWER metric whose
importance is highlighted in the below mentioned sections. This POWER
metric is obtained by including the factors such as power consumed by
a linecard on a single chassis or multi-chassis router and
consequently a port on that linecard by proportionally calculating
power consumed for that port and hence for the link. The other factor
that is taken into account is the Available Bandwidth on that port
and hence on that link.
2. Methodology
For each router / switch there exist linecards and each linecard has
a set of ports or sometimes just one port of high capacity. This
usually applies on routers and switches that are either single
chassis or multi-chassis in their characterisation. By single chassis
we mean that there exists a single chassis and slots for the Route
Processor Card (one or more of these) typically upto to two of them,
and one or more slots for linecards each having their respective
characteristics such as number of ports (port density), type of such
ports (SONET, ethernet, ATM etc..) usually depending on the link
layer technology they support. Links are connections between ports on
these linecards to other ports on linecards of other single chassis
or multi-chassis system. A multi-chassis system is one that has
multiple such chassis interconnceted amongst each other to form a
single logical view of the system. Both single and multi-chassis have
linecards and respective ports on these linecards. Multi-chassis
typically have a switch fabric chassis which connects each of these
chassis to each other or to chassis of other multi-chassis or single
chassis systems.
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Consider the following topology...
Router A Router B Router C
+---+---+ +---+---+ +-------+
| | | | | | | | |
|LC1|LC2| |LC1|LC2| |LC1|LC2|
| | | | | | L11 | | |
| P1| P1| | P1| P1|-------------- P1| P1|---+
| P2| P2|--+ | P2| P2| L12 | P2| P2| |
| P3| P3| | L4 | P3| P3|-------------- P3| P3| |
| P4| P4|--+----------- P4| P4| +---- P4| P4| |
| P5| P5| | +----P5| P5--+ L5 | | P5| P5| |
| | | | | | | | | | | | | | | | |
+-|-+-|-+ |L3 | +---+---+ | | +---+-|-+ | L13
| | | +------------+-------+ | |
| |L2 | L5 | | |
| +----+------------+ | | |
| | | | | |
|L1 | | |L6 | |
| | Router D | | Router E L12| | Router F
| | +---+---+ | | +---+---+ | |+-------+
| | | | | |L2 | | | | | || | |L
| | |LC1|LC2| | | |LC1|LC2| | ||LC1|LC2|1
| | | | | | | | | | | || | |4..
| +-| P1| P1---+ | | P1| P1|------+ || P1| P1|->
| | P2| P2| L7 +--- P2| P2| +--P2| P2|->
| | P3| P3|-------------- P3| P3| L10 | P3| P3|->
+----------| P4| P4| +---- P4| P4|-------------- P4| P4|
| P5| P5| | +-- P5| P5| +----- P5| P5|
| | | | | | | | | | | | |
+-|-+---+ L8 | | +---+---+ L9 | +---+---+
+---------------+ +------------------+
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The table of links between the various routers (which are assumed to
be single chassis systems) is as follows...
+--------+----------+-----------+-----------+-----------+----------+
| Links | Routers | LC <> LC | Port Conn.| Capacity |Available |
| | | | | |Bandwidth |
+--------+----------+-----------+-----------+-----------+----------+
| L1 | A <> D | LC1<>LC1 | P5<>P4 | 10G | 7.5 |
| L2 | A <> D | LC2<>LC2 | P5<>P1 | 10G | 6.0 |
| L3 | A <> D | LC2<>LC1 | P2<>P1 | 10G | 4.0 |
| L4 | A <> B | LC2<>LC1 | P4<>P4 | 10G | 3.0 |
| L5 | B <> C | LC1<>LC1 | P5<>P4 | 10G | 3.5 |
| L6 | B <> E | LC1<>LC1 | P6<>P2 | 10G | 1.0 |
| L7 | D <> E | LC2<>LC1 | P3<>P3 | 10G | 6.0 |
| L8 | D <> E | LC1<>LC1 | P5<>P4 | 10G | 1.5 |
| L9 | E <> F | LC1<>LC2 | P5<>P5 | 100G | 20.0 |
| L10 | E <> F | LC2<>LC1 | P4<>P4 | 10G | 2.5 |
| L11 | B <> C | LC2<>LC1 | P1<>P1 | 10G | 3.0 |
| L12 | E <> C | LC2<>LC2 | P1<>P5 | 10G | 2.0 |
| L13 | C <> F | LC2<>LC1 | P1<>P2 | 10G | 1.0 |
| L14 | F <> OA | LC2<> | P1<> | | |
| | | | | | |
+--------+----------+-----------+-----------+------------+---------+
In the above topology assume all point-to-point links between the
routers. For now we will deal with P2P links alone and not venture
into Broadcast Multi-access links or Non-Broadcast Multi-access links
etc.. It is suffice to show how the scheme works for P2P links and
then move more specifically to other types of networks to demonstrate
this method of calculating the power topology of the network in the
figure.
Each linecard consumes a certain amount of power and it is vendor
dependent as to how the power consumed relates to the Available
Bandwidth on any of the links to which the linecard connects to. It
is possible that the said topology of routers come from one vendor or
from multiple vendors. It is assumed that the algorithm proposed will
have the power consumed by a linecard available as a readable value
in terms of W or kW or whichever measurable metric that is provided
by the vendor.
It is possible that some of the Linecards are more capable than the
others. Consider that Router A is a more capable router with more
powerful linecards with higher port density. This is not shown in the
figure, but assume so. LC1, LC2 on Router A could be consuming more
power than the other Linecards on other routers. The main reason
could be that LC1 and LC2 may have higher port density or higher
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speed ports than the other routers. In order to calculate the power
consumed on a link by a linecard it is important that we normalize
the power as power consumed per port. Here the ports are normalized
to lowest common denominator. If all links in the topology have 10G
port capacity then the power calculated should be in terms power
consumed per 10G port.
Assuming we have done this normalization we go on to calculate the
POWER metric for each of the ports involved in a link which is
derived as follows...
POWER metric = Power consumed per XG (normalized bandwidth) port
for a given -------------------------------------------------
Port on a LC Available Bandwidth on that port
Assume link L1. The ports concerned are both 10G and the ports are P5
on Router A and P4 on Router D. For calculating the POWER metric for
a link which we will call PWRLINK we calculate the POWER metric for
each side of the link and average the two to get PWRLINK.
So PWRLINK for L1 = POWER for P5 on LC1 + Power for P4 on LC1
on Router A on Router D
============================================
2
The above can also be weighted if there is a multi-capacity port on
one side of the link and not on the other. A multi-capacity link is
one which provides multiple bandwidth capabilities such (1G/10G/100G)
for example but auto-negotiates with other end to provide a lesser
than highest capacity service.
The PWRLINK metrices once calculated are flooded in already defined
OSPF-TE-LSA as an adapted TE-metric and is typically flooded as a
link characteristic.
It is important to note that the denominator for POWER metric is
Available Bandwidth on that port. The Available Bandwidth is measured
in terms of intervals and not as discrete quantities. This is in
order not to flood PWRLINK metrics into the OSPF area in LSAs very
frequently as Bandwidth may constantly change. The same applies to
POWER metric as well.
Once the LSAs have been flooded the Routers run regular SPF on the
graph of the topology with PWRLINKs assigned to the links and
calculate the PWRLINK based paths which consume the least power. The
shortest power paths based on this topology can be used for
forwarding high bandwidth streams and to optimally use power within
the area.
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The Available Bandwidth column shows the Available bandwidth of the
link corresponding to the row and column intersection. This figure is
used as the numerator in the POWER metric computation for that port.
2.0.1 Experimental results and their inferences
The first experiments were carried out with Available Utilization
since only 10G and 100G ports were considered. This baselines the
metric to 10G ports and proportionality thereof. But in reality the
actual Available Bandwidth needs to be considered for real world
experiments. Hence this draft has been adapted to reflect the
Available Bandwidth to be taken as the denominator of the formula
thereof.
Dividing the Power consumed or Available Power by the Available
Bandwidth gives a better picture of how much power cost per Gb is
consumed and normalizes the metric amongst links of varying
bandwidth.
Please refer to the section on Power Profiles where the different
decisions in the SPF computation are described.
2.1 Power Bias
Assume in the figure that there exist Routers A and D and that there
is a bias on the link L1 in such a way that Router D computes a POWER
metric of 10 and the Router D computes a POWER metric of 2 on the
ports P5 and P4 respectively. Now the PWRLINK would be 6 for that
link L1. Thus even if one side is excessively power guzzling then the
PWRLINK moves up and thus is less preferred in the CSPF algorithm and
path computation based on the Power topology.
If there is no bias and both the sides of the link are optimal in
their power usage then the metric stays low even if more streams are
sent on it. This is the main objective that is set out for router and
switch manufacturers in the single chassis and multi-chassis world,
in that they are incentivised to manufacture linecards that are not
power hungry even if the number of packets flowing through them is
high and thus the Bandwidth Available is also reasonably on the
higher side compared to other routers.
For those manufacturers who set a high power value for even minimal
traffic, the vendors that dont would win out in the end.
2.1.1 Advertising Available POWER
Please see section 2.4.1 for more information on why Available POWER
plays a crucial role in determining the choice of routers based on
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the Power metric.
2.2 ECMP links
It is possible that multiple links would have the same PWRLINK metric
after a computation cycle. In such a case load-balancing techniques
can be used to keep the ECMP links in a steady state with respect to
each other. Depending on the Available Bandwidth thereafter it is
possible that the ECMP links may no longer be Equal cost but UCMP or
Unequal Cost Paths.
2.3 Dampening the side effects of constant change
It is recommended in this draft that the implementation of the
proposal be adaptive, infrequent in computation to the extent
possible without sacrificing adapting to the dynamism and also reduce
any frequent oscillations. It SHOULD be specified that intervals of
Available bandwidth and Consumed-Power or Available-Power be used
instead of discrete values in arriving at the power ratios. This will
dampen any frequent SPF computation for the power based topology.
Even if intervals are used dampening fluctuations should be in place
to prevent frequent re-computation of the SPF tree.
2.4 Calculating power shortest paths in an Area
Assume the following topology where A,B,C etc.. are routers and
corresponding labelled edges with weights are the links. These
weights are the current values of the PWRLINK attribute that has been
flooded in the LSAs through the Area concerned. Assume B is the ABR
for Area 1 and the routers A and C are the Area 0 core routers. The
rest of the routers are assumed to be in Area 1. Once the power
topology of the Area 1 has been calculated as shown below with the
PWRLINK attributes being assigned to the links, Power based shortest
path first (SPF) computation can be run on the routers say. The SPF
algorithm does its computation for the power topology which is
characterized in terms of the PWRLINK attributes along with other
attributes to construct a power shortest path tree from the router
performing the computation to all the destinations in the area.
Calculations for the power based topology are done on ABRs, ASBRs and
area core routers.
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0.5
(C) +----------------+
0.5| / |
| / |
0.05 V/ 0.1 0.03 0.2 V
(A)--->(B)--->(D)--->(G)--->(H)
| | |
| 0.5| | 0.1
| V V
+----------->(E)--->(X)
0.5 0.3
The power based SPT on router B would look like as shown below. The
regular SPT may be divergent from this picture.
0.5
(C) +................+
0.5| . .
| . .
0.05 V. 0.1 0.03 0.2 V
(A)--->(B)...>(D)...>(G)----->(H)
. | .
. 0.5| . 0.1
. V V
+...........>(E)--->(X)
0.5 0.3
2.4.1 Power profiles of Routers and Switches and SPF computation
It has been experimented and from several sources found that there
exist routers which have different power profiles. The power profile
of a router is the curve of power consumption to available bandwidth.
Mentioned below are a few of these prominent ones that have to be
taken into consideration. The power based SPF computation follows the
procedures specified below when confronted with two or more routers
that have reachability to destinations in its calculation for the
power based shortest path tree.
The first profile that we will consider is the flattening curve. The
power consumed to available bandwidth curve takes the shape of a
steep one initially and then tapers off to a plateau. The point at
which it begins to give a delta-C (delta in Power Consumed) to delta-
B (Available Bandwidth exhausted) is the inflection point that tapers
off to a plateau. Here the delta-C/delta-B begins to slow down or
decrease rapidly. The more the traffic that is added onto the device
the lesser it draws power.
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^
|
P | .
o | .
w | .
e | .
r | .
| .
c | .
o | .
n | .
s | .
u.| .
------------------------------------>
| Available Bandwidth exhausted
The second profile that we will consider is the exponential curve.
The power consumed to available bandwidth curve takes the shape of an
ever increasing steep curve as shown below. Here the delta-C/delta-B
begins to increase as more traffic is thrown onto it as the Available
bandwidth exhausted increases. This power curve beyond a point is
intolerable with respect to power guzzling.
^
|
P | .
o | .
w | .
e | .
r | .
| .
c | .
o | .
n | .
s | .
u.| .
------------------------------------>
| Available Bandwidth exhausted
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The third profile that we will consider is a linear curve. In other
words just a straight line. Here delta-C/delta-B is a constant.
^
|
P | .
o | .
w | .
e | .
r | .
| .
c | .
o | .
n | .
s | .
u.| .
------------------------------------>
| Available Bandwidth exhausted
2.4.1.1 Concave and Convex power curves
Given that there are 3 kinds of major profiles in the router power
consumption, what line would we like to pick. This is an important
point when choosing the metric to pick the low power paths.
(a) If the confrontation is between 2 first profile routers the lower
of the 2 would be considered as shown below. The lower curve offers
better power savings for each GB of bandwidth transported.
^
|
P | .
o | .
w | . .
e | . .
r | . .
| . .
c | . .
o | . .
n | . .
s | . .
u.| .
------------------------------------>
| Available Bandwidth exhausted
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(b) If the confrontation is between 2 second profile routers the
upper curve offers more power savings per GB of bandwidth.
^
|
P | . .
o | . .
w | . .
e | . .
r | . .
| . .
c | . .
o | . .
n | . .
s | .
u.| .
------------------------------------>
| Available Bandwidth exhausted
(c) When the confrontation is between a first profile curve and a
second profile curve, it would be optimal to pick (as shown below)
the lower of the curves because it gives us lesser power consumed for
every GB of traffic routed / switched. Here the exponential curve is
the one that offers lesser amount of power consumed per GB of traffic
is chosen. But when it gets to a point that the two curves intersect
it would be more optimal to pick the tapering curve. Thus at the
meeting point of the 2 curves the exponential curve becomes more
costly and the tapering one gives us more GB for the power buck. Thus
this switchover from one curve to the other (in other words from the
exponential curve to the tapering one) does the trick in terms of
finding an optimal solution.
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^ .
| .
P | . .
o | (*)
w | . .
e | . .
r | . .
| . .
c | . .
o | . .
n | . .
s | . .
u.| ..
------------------------------------>
| Available Bandwidth exhausted
(*) Metric switchover point from Consumed Power to Available
Power.
2.4.1.3 Need to advertise both available power and consumed power
Thus the above sections have shown that both the available power and
the consumed power MUST be advertised so that case (c) can be
deciphered and the switchover of the curves be done and the
appropriate router be chosen for the rest of the bandwidth to be
switched over to.
Thus there will exist Consumed-Power to Available Bandwidth ratio and
the Available Power to Available Bandwidth ratio. Both the ratios are
computed and the lower value chosen. The Available Power can be
judged from the calibration process such as the one carried out by
independent test organizations as in [12]. An example of their
calibration is referred to in [12].
Here given below is the formula for calculating the Available Power
to Available Bandwidth ratio also called the Available POWER metric.
Available
POWER metric = Available Power consumed per XG
(normalized bandwidth) port
for a given ----------------------------------
Port on a LC Available Bandwidth on that port
2.4.2 Power to Available Bandwidth ratio in a TLV
As per [RFC3630] the Link TLV can be used to carry this power to
available Bandwidth ratio with an additional sub-TLV of the link TLV.
The sub-type number 11 is recommended to be defined for this purpose.
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[RFC 3630] states in section 2.2.1 and we QUOTE ...
2.2.1 Link TLV
The Link TLV describes a single link. It is constructed of a set of
sub-TLVs. There are no ordering requirements for the sub-TLVs.
Only one Link TLV shall be carried in each LSA, allowing for fine
granularity changes in topology.
The Link TLV is type 2, and the length is variable.
The following sub-TLVs of the Link TLV are defined:
1 - Link type (1 octet)
2 - Link ID (4 octets)
3 - Local interface IP address (4 octets)
4 - Remote interface IP address (4 octets)
5 - Traffic engineering metric (4 octets)
6 - Maximum bandwidth (4 octets)
7 - Maximum reservable bandwidth (4 octets)
8 - Unreserved bandwidth (32 octets)
9 - Administrative group (4 octets)
10 - Power-to-Multicast-replication-capacity (4 octets)
11 - Consumed-Power-to-Available-Bandwidth (4 octets)
12 - Available-Power-to-Available-Bandwidth (4 octets)
This memo defines sub-Types 1 through 9. See the IANA Considerations
in [RFC3630] section for allocation of new sub-Types.
The Link Type and Link ID sub-TLVs are mandatory, i.e., must appear
exactly once. All other sub-TLVs defined here may occur at most
once. These restrictions need not apply to future sub-TLVs.
Unrecognized sub-TLVs are ignored.
Various values below use the (32 bit) IEEE Floating Point format. For
quick reference, this format is as follows:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|S| Exponent | Fraction |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
S is the sign, Exponent is the exponent base 2 in "excess 127"
notation, and Fraction is the mantissa - 1, with an implied binary
point in front of it. Thus, the above represents the value:
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(-1)**(S) * 2**(Exponent-127) * (1 + Fraction)
It is proposed that we use the Power-to-Available-Bandwidth ratio as
a 32 bit IEEE floating Point format field for the purpose of this
document.
2.4.3 LDP Capability Parameter TLV for Power-SPF based label exchanges
As per [5561] a capability parameter TLV can be exchanged at the
initialization time or when the administrator fo the network turns on
the feature later on. On turning on this feature, the power based
shortest-path computation is done and labels exchanged for prefixes
through regular LDP operation. The set of labels used for this power
based shortest-path tree is disjoint from the label space used for
regular IPoMPLS LDP and other features enabled.
2.4.4 When one peer says Power-SPF is fine but the other doesnt
All the peers should advertise this capability. In other words all of
the routers in the area should be involved in disseminating power SPT
based labels.
2.4.5 Mapping flows to the Power based SPT
It is possible to map FECs (Forwarding Equivalence classes) some or
all of them to the power based SPT. This offers flexibility to the
admin to map certain set of large flows to the least power consuming
routers in the topology thus getting the best bang for the bit as far
as power is concerned.
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3 Security Considerations
No additional security considerations are required other than the
existing mechanisms available for securing LDP exchanges.
4 IANA Considerations
New requirements are required from IANA for a new type in the Link
TLV in order to carry the PWRLINK metric as well. This is needed for
both Consumed Power Ratio and Available Power Ratio.
A new code-point for the Capability Parameter TLV needs to be
assigned for indicating that a router supports power based SPT and
label space thereof.
5 References
5.1 Normative References
5.2 Informative References
[5561] Thomas et.al, LDP Capabilities, July 2009,
[1] G. Appenzeller, Sizing router buffers, Doctoral Thesis,
Department of Electrical Engineering, Stanford University,
2005.
[2] A. P. Bianzino, C. Chaudet, D. Rossi and J. L. Rougier, A survey
of green networking research, IEEE Communications and
Surveys Tutorials, preprint.
[3] J. Baliga, K. Hinton and R. S. Tucker, Energy consumption of the
internet, Proc. of joint international conference on
optical internet, June 2007, pp. 1-3.
[4] J. Chabarek, J. Sommers, P. Barford, C. Estan, D. Tsiang and S.
Wright, Power awareness in network design and routing,
Proc. of the IEEE INFOCOM 2008, April 2008, pp. 457-465.
[5] B. Venkat et.al, Constructing disjoint and partially disjoint
InterAS TE-LSPs, USPTO Patent 7751318, Cisco Systems,
2010.
[6] M. Xia et. al., Greening the optical backbone network: A traffic
engineering approach, IEEE ICC Proceedings, May 2010, pp.
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1-5.
[7] W. Lu and S. Sahni, Low-power TCAMs for very large forwarding
tables, IEEE/ACM Transactions on Computer Networks, June
2010, vol. 18, no. 3, pp. 948-959.
[8] B. Zhang, Routing Area Open Meeting, Proceedings of the IETF 81,
Quebec, Canada, July 2011.
[9] M.J.S Raman, V.Balaji Venkat, G.Raina, Reducing Power consumption
using the Border Gateway Protocol, IARIA conferences
ENERGY 2012.
[10] A.Cianfrani et al., An OSPF enhancement for energy saving in IP
Networks, IEEE INFOCOM 2011 Workshop on Green
Communications and Networking
[12] http://www.juniper.net/us/en/local/pdf/validation-reports/eantc-
mx-marketing-report.pdf, September 2009.
Authors' Addresses
Shankar Raman
Department of Computer Science and Engineering,
IIT Madras
Chennai - 600036
TamilNadu
India.
EMail: mjsraman@cse.iitm.ac.in
Balaji Venkat Venkataswami
Department of Electrical Engineering
IIT Madras
Chennai - 600036
TamilNadu
India.
EMail: balajivenkat299@gmail.com
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Prof.Gaurav Raina
Department of Electrical Engineering
IIT Madras
Chennai - 600036
TamilNadu
India.
EMail: gaurav@ee.iitm.ac.in
Vasan Srini
Department of Computer Science and Engineering
IIT Madras
Chennai - 600036
TamilNadu
India.
EMail: vasan.vs@gmail.com
Shankar Raman et.al, Expires November 11, 2013 [Page 19]
