U.S. patent application number 16/939111 was filed with the patent office on 2020-11-12 for deadlock-free traffic rerouting in software-defined networking networks.
This patent application is currently assigned to AT&T Intellectual Property I, L.P.. The applicant listed for this patent is AT&T Intellectual Property I, L.P.. Invention is credited to Gagan Choudhury, Alvin Goddard, Narayan Padi, Aswatnarayan Raghuram, Simon Tse, Kang Xi.
Application Number | 20200358697 16/939111 |
Document ID | / |
Family ID | 1000004978172 |
Filed Date | 2020-11-12 |
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United States Patent
Application |
20200358697 |
Kind Code |
A1 |
Choudhury; Gagan ; et
al. |
November 12, 2020 |
Deadlock-Free Traffic Rerouting in Software-Defined Networking
Networks
Abstract
Concepts and technologies disclosed herein are directed to
deadlock-free traffic rerouting in software-defined networking
("SDN") networks. According to one aspect of the concepts and
technologies disclosed herein, a centralized SDN controller can
determine that a packet flow along a path within at least a portion
of a network is to be rerouted from the path to a new path. The
centralized SDN controller can initiate a reroute of the packet
flow to the new path. The centralized SDN controller can request a
bandwidth for the new path. The bandwidth can be determined such
that bandwidth oversubscription on the new path is avoided. In
response to the packet flow settling on the new path, the
centralized SDN controller can adjust a requested bandwidth of the
packet flow to a desired value to complete the reroute of the
packet flow from the path to the new path.
Inventors: |
Choudhury; Gagan; (Jackson,
NJ) ; Xi; Kang; (Morganville, NJ) ; Tse;
Simon; (Holmdel, NJ) ; Padi; Narayan; (Cedar
Knolls, NJ) ; Goddard; Alvin; (Kendall Park, NJ)
; Raghuram; Aswatnarayan; (Morganville, NJ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
AT&T Intellectual Property I, L.P. |
Atlanta |
GA |
US |
|
|
Assignee: |
AT&T Intellectual Property I,
L.P.
Atlanta
GA
|
Family ID: |
1000004978172 |
Appl. No.: |
16/939111 |
Filed: |
July 27, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
15845280 |
Dec 18, 2017 |
10728140 |
|
|
16939111 |
|
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04L 41/145 20130101;
H04L 47/11 20130101; H04L 45/42 20130101; H04L 45/64 20130101; H04L
45/28 20130101; H04L 45/56 20130101; H04L 41/0896 20130101; H04L
47/2441 20130101; H04L 47/122 20130101; H04L 45/50 20130101; H04L
45/38 20130101; H04L 45/22 20130101 |
International
Class: |
H04L 12/721 20060101
H04L012/721; H04L 12/723 20060101 H04L012/723; H04L 12/771 20060101
H04L012/771; H04L 12/24 20060101 H04L012/24; H04L 12/803 20060101
H04L012/803; H04L 12/851 20060101 H04L012/851; H04L 12/801 20060101
H04L012/801; H04L 12/715 20060101 H04L012/715; H04L 12/717 20060101
H04L012/717; H04L 12/707 20060101 H04L012/707; H04L 12/703 20060101
H04L012/703 |
Claims
1. A software-defined network comprising: a plurality of network
nodes that, in various combinations, form a plurality of network
links, each of which has a specific bandwidth capacity; and a
software-defined networking controller comprising a processor, and
memory having instructions stored thereon that, when executed by
the processor, cause the processor to perform operations comprising
determining that a portion of the plurality of network links is in
a congested state, wherein the congested state comprises the
specific bandwidth capacity of the portion of the plurality of
network links being exceeded by a bandwidth demand of a path,
determining, based upon the congested state, that the path is to be
rerouted to a new path, determining that the path cannot be
rerouted to the new path due to a deadlock condition, initiating,
due to the deadlock condition, a reroute of the path to the new
path by requesting a requested bandwidth comprising a bandwidth
value of the bandwidth demand of the path, and completing the
reroute by adjusting the requested bandwidth from the bandwidth
value to a desired bandwidth value.
2. The software-defined network of claim 1, wherein the operations
further comprise: determining that a further portion of the
plurality of network links is in the congested state, wherein the
congested state further comprises the specific bandwidth capacity
of the further portion of the plurality of network links being
exceeded by a further bandwidth demand of a further path;
determining, based upon the congested state, that the further path
is to be rerouted to a further new path; determining that the
further path cannot be rerouted to the further new path due to the
deadlock condition; initiating, due to the deadlock condition, a
further reroute of the further path to the further new path by
requesting a further requested bandwidth comprising a further
bandwidth value of the further bandwidth demand of the further
path; and completing the further reroute by adjusting the requested
bandwidth from the bandwidth value to a desired bandwidth
value.
3. The software-defined network of claim 2, wherein the operations
for initiating the reroute, completing the reroute, initiating the
further reroute, and completing the further reroute are based upon
at least one routing model.
4. The software-defined network of claim 3, wherein initiating the
reroute, completing the reroute, initiating the further reroute,
and completing the further reroute each comprises generating
commands directed to at least one network node of the plurality of
network nodes, and sending the commands to the at least one network
node.
5. The software-defined network of claim 2, wherein the bandwidth
value comprises a proportionally small bandwidth, and wherein the
further bandwidth value comprises a further proportionally small
bandwidth.
6. The software-defined network of claim 2, wherein the further
bandwidth value comprises a further percentage of a total
bandwidth, and wherein the further desired bandwidth value
comprises the total bandwidth.
7. The software-defined network of claim 1, wherein the bandwidth
value comprises a percentage of a total bandwidth, and wherein the
desired bandwidth value comprises the total bandwidth.
8. A computer-readable storage medium comprising
computer-executable instructions that, when executed by a
processor, causes the processor to perform operations comprising:
determining that a portion of a plurality of network links is in a
congested state, wherein the congested state comprises a specific
bandwidth capacity of the portion of the plurality of network links
being exceeded by a bandwidth demand of a path; determining, based
upon the congested state, that the path is to be rerouted to a new
path; determining that the path cannot be rerouted to the new path
due to a deadlock condition; initiating, due to the deadlock
condition, a reroute of the path to the new path by requesting a
requested bandwidth comprising a bandwidth value of the bandwidth
demand of the path; and completing the reroute by adjusting the
requested bandwidth from the bandwidth value to a desired bandwidth
value.
9. The computer-readable storage medium of claim 8, wherein the
operations further comprise: determining that a further portion of
the plurality of network links is in the congested state, wherein
the congested state further comprises the specific bandwidth
capacity of the further portion of the plurality of network links
being exceeded by a further bandwidth demand of a further path;
determining, based upon the congested state, that the further path
is to be rerouted to a further new path; determining that the
further path cannot be rerouted to the further new path due to the
deadlock condition; initiating, due to the deadlock condition, a
further reroute of the further path to the further new path by
requesting a further requested bandwidth comprising a further
bandwidth value of the further bandwidth demand of the further
path; and completing the further reroute by adjusting the requested
bandwidth from the bandwidth value to a desired bandwidth
value.
10. The computer-readable storage medium of claim 9, wherein the
operations for initiating the reroute, completing the reroute,
initiating the further reroute, and completing the further reroute
are based upon at least one routing model.
11. The computer-readable storage medium of claim 10, wherein
initiating the reroute, completing the reroute, initiating the
further reroute, and completing the further reroute each comprises
generating commands directed to at least one network node of the
plurality of network nodes, and sending the commands to the at
least one network node.
12. The computer-readable storage medium of claim 9, wherein the
bandwidth value comprises a proportionally small bandwidth, and
wherein the further bandwidth value comprises a further
proportionally small bandwidth.
13. The computer-readable storage medium of claim 9, wherein the
further bandwidth value comprises a further percentage of a total
bandwidth, and wherein the further desired bandwidth value
comprises the total bandwidth.
14. The computer-readable storage medium of claim 8, wherein the
bandwidth value comprises a percentage of a total bandwidth, and
wherein the desired bandwidth value comprises the total
bandwidth.
15. A method comprising: determining, by a software-defined
networking controller, that a portion of the plurality of network
links is in a congested state, wherein the congested state
comprises a specific bandwidth capacity of the portion of the
plurality of network links being exceeded by a bandwidth demand of
a path; determining, by the software-defined networking controller,
based upon the congested state, that the path is to be rerouted to
a new path; determining, by the software-defined networking
controller, that the path cannot be rerouted to the new path due to
a deadlock condition; initiating, by the software-defined
networking controller, due to the deadlock condition, a reroute of
the path to the new path by requesting a requested bandwidth
comprising a bandwidth value of the bandwidth demand of the path;
and completing, by the software-defined networking controller, the
reroute by adjusting the requested bandwidth from the bandwidth
value to a desired bandwidth value.
16. The method of claim 15, comprising: determining that a further
portion of the plurality of network links is in the congested
state, wherein the congested state further comprises the specific
bandwidth capacity of the further portion of the plurality of
network links being exceeded by a further bandwidth demand of a
further path; determining, based upon the congested state, that the
further path is to be rerouted to a further new path; determining
that the further path cannot be rerouted to the further new path
due to the deadlock condition; initiating, due to the deadlock
condition, a further reroute of the further path to the further new
path by requesting a further requested bandwidth comprising a
further bandwidth value of the further bandwidth demand of the
further path; and completing the further reroute by adjusting the
requested bandwidth from the bandwidth value to a desired bandwidth
value.
17. The method of claim 16, wherein initiating the reroute,
completing the reroute, initiating the further reroute, and
completing the further reroute are based upon at least one routing
model.
18. The method of claim 16, wherein initiating the reroute,
completing the reroute, initiating the further reroute, and
completing the further reroute each comprises generating commands
directed to at least one network node of the plurality of network
nodes, and sending the commands to the at least one network
node.
19. The method of claim 15, wherein the bandwidth value comprises a
proportionally small bandwidth.
20. The method of claim 15, wherein the further bandwidth value
comprises a proportionally small bandwidth.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of and claims priority to
U.S. patent application Ser. No. 15/845,280, entitled
"Deadlock-Free Traffic Rerouting in Software-Defined Networking
Networks," filed Dec. 18, 2017, now allowed, which is incorporated
herein by reference in its entirety.
BACKGROUND
[0002] Software-defined networking ("SDN") has gained momentum
among providers of network services, including data centers, cloud
computing, and wide-area networks ("WANs") service providers. SDN
networks allow service providers to create and activate new
services and to update existing services on-demand and in near
real-time. SDN networks provide network-on-demand services that
allow network infrastructure to adapt to user demand.
[0003] SDN networks implement one or more SDN controllers to
control operations of an SDN network, and one such operation is
traffic routing. An SDN controller can determine traffic routes and
instruct network routers to route data traffic along specific
paths. If an SDN network is currently routing traffic on a set of
paths and the SDN controller determines that a better route is
available via a different set of paths, then the SDN controller
also can determine that rerouting the network traffic is preferred.
Rerouting the network traffic, however, is not straight-forward and
could result in transient deadlocks where the network traffic, when
rerouted using a traditional approach, would become overburdened
and fail due to lack of available bandwidth.
SUMMARY
[0004] Concepts and technologies disclosed herein are directed to
deadlock-free traffic rerouting in SDN networks. According to one
aspect of the concepts and technologies disclosed herein, a
centralized SDN controller can determine that a packet flow along a
path within at least a portion of a network is to be rerouted from
the path to a new path. The centralized SDN controller can initiate
a reroute of the packet flow to the new path. The centralized SDN
controller can request a bandwidth for the new path. The bandwidth
can be determined such that bandwidth oversubscription on the new
path is avoided. In response to the packet flow settling on the new
path, the centralized SDN controller can adjust a requested
bandwidth of the packet flow to a desired value to complete the
reroute of the packet flow from the path to the new path.
[0005] In some embodiments, the network can be or can include a
multiprotocol label switching ("MPLS") network. In these
embodiments, the path can include a label switched path ("LSP") and
the new path can include a new LSP.
[0006] In some embodiments, the portion of the network includes a
network link between a first network node and a second network
node. The first network node can include a first router and the
second network node can include a second router. The first and
second routers are unable to perform rerouting to resolve
congestion of the network link. The network link can include a
bandwidth capacity, and the congestion can result from a threshold
percentage of the bandwidth capacity being reached or exceeded.
[0007] In some embodiments, the centralized SDN controller can
determine that a further packet flow along a further path within at
least a further portion of the network is to be rerouted from the
further path to a further new path. The centralized SDN controller
can initiate a further reroute of the further packet flow to the
further new path. The centralized SDN controller can request a
further bandwidth for the further new path. The further bandwidth
can be determined such that bandwidth oversubscription on the
further new path is avoided. In response to the further packet flow
settling on the further new path, the centralized SDN controller
can adjust a further requested bandwidth of the further packet flow
to a further desired value to complete the further reroute of the
further packet flow from the further path to the further new
path.
[0008] It should be appreciated that the above-described subject
matter may be implemented as a computer-controlled apparatus, a
computer process, a computing system, or as an article of
manufacture such as a computer-readable storage medium. These and
various other features will be apparent from a reading of the
following Detailed Description and a review of the associated
drawings.
[0009] This Summary is provided to introduce a selection of
concepts in a simplified form that are further described below in
the Detailed Description. This Summary is not intended to identify
key features or essential features of the claimed subject matter,
nor is it intended that this Summary be used to limit the scope of
the claimed subject matter. Furthermore, the claimed subject matter
is not limited to implementations that solve any or all
disadvantages noted in any part of this disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIGS. 1A-1C are example network graphs showing that
congestion appearing as a deadlock to distributed routing can be
resolved by centralized control via a centralized SDN
controller.
[0011] FIG. 2 is a block diagram illustrating aspects of an SDN
network capable of implementing aspects of the embodiments
presented herein.
[0012] FIG. 3 is a flow diagram illustrating a method for deadlock
free traffic rerouting in an SDN network, according to an
illustrative embodiment.
[0013] FIG. 4 is a block diagram illustrating aspects of an
illustrative cloud environment capable of implementing aspects of
the embodiments presented herein.
[0014] FIG. 5 is a block diagram illustrating an example computer
system capable of implementing aspects of the embodiments presented
herein.
[0015] FIG. 6 is a diagram illustrating a network, according to an
illustrative embodiment.
DETAILED DESCRIPTION
[0016] While the subject matter described herein may be presented,
at times, in the general context of program modules that execute in
conjunction with the execution of an operating system and
application programs on a computer system, those skilled in the art
will recognize that other implementations may be performed in
combination with other types of program modules. Generally, program
modules include routines, programs, components, data structures,
computer-executable instructions, and/or other types of structures
that perform particular tasks or implement particular abstract data
types. Moreover, those skilled in the art will appreciate that the
subject matter described herein may be practiced with other
computer systems, including hand-held devices, mobile devices,
wireless devices, multiprocessor systems, distributed computing
systems, microprocessor-based or programmable consumer electronics,
minicomputers, mainframe computers, routers, switches, other
computing devices described herein, and the like.
[0017] Turning now to FIGS. 1A-1C, example network graphs 100A-100C
will be described. The network depicted in the network graphs
100A-100C can implement multiprotocol label switching ("MPLS") for
routing. The concepts and technologies disclosed herein are not
limited to MPLS and are equally applicable to general flow-based
routing. Accordingly, those skilled in the art will appreciate the
applicability of alternative protocols to implement the concepts
and technologies disclosed herein.
[0018] The network graphs 100A-100C show that congestion appearing
as a deadlock in a distributed routing framework can be resolved by
control provided by a centralized SDN controller (best shown in
FIG. 2). The network graphs 100A-100C each illustrate two source
(headend) routers 102A ("S1"), 102B ("S2"), two middle routers 104A
("M1"), 104B ("M2"), and one destination router 106 ("D") that, in
various combinations, form a plurality of network links ("links")
108A-108G, each of which has a specific bandwidth capacity. In
particular, a link S1-S2 108A provides 100 Gigabits per second
("Gbps") of bandwidth; a link S1-M1 108C provides 100 Gbps; a link
S1-M2 108B provides 100 Gbps; a link S2-M1 108D provides 100 Gbps;
a link S2-M2 108E provides 100 Gbps; a link M2-D 108F provides 50
Gbps; and a link M1-D 108G provides 100 Gbps.
[0019] FIG. 1A illustrates a first network graph 100A
representative of an initial state in which no congestion exists on
any of the links 108A-108G. The first network graph 100A also shows
two label switching paths ("LSPs")--LSP1 110A and LSP2 110B--both
of which only utilize 40 Gbps of bandwidth, which is well below the
bandwidth capacity of the links 108C, 108G through which the LSP1
110A traverses, and well below the bandwidth capacity of the links
108E, 108F through which the LSP2 110B traverses. As used herein,
the terms "path" and "route" are used interchangeably because a
single path is chosen as the route for packet flows.
[0020] FIG. 1B illustrates a second network graph 100B
representative of a traffic surge and the resultant high load (80
Gbps) on LSP2 110B. The traffic surge causes congestion on the link
M2-D 108F. FIG. 1C illustrates a third network graph 100C
representative of a feasible re-routing solution to resolve the
congestion on the link M2-D 108F shown in FIG. 1B. However, the two
source (headend) routers--S1 102A and S2 102B--working in a
distributed configuration without coordination therebetween are
unable to execute a feasible re-routing solution. For the LSP2
110B, the source router S2 102B observes only 60 Gbps of available
bandwidth capacity on the alternative path S2-M1-D, which is
insufficient to meet the bandwidth demand (80 Gbps) of LSP2 110B.
Similarly, the source router S1 102A for the LSP1 110A observes
only 10 Gbps available on the alternative path S1-M2-D, which is
insufficient to meet the bandwidth demand (40 Gbps) of LSP1 110A,
and thus the source router S1 102A cannot re-route LSP1 110A to
resolve the congestion. This creates a deadlock situation in the
network. The concepts and technologies disclosed herein solve
deadlock situations by guaranteeing that re-routing will succeed by
implementing a centralized SDN controller, which will now be
described with reference to FIG. 2.
[0021] Turning now to FIG. 2, aspects of an SDN network 200 capable
of implementing aspects of the embodiments presented herein will be
described. The SDN network 200 will be described with reference to
FIG. 2 and additional reference to FIGS. 1B, 1C for context. The
SDN network 200 includes a centralized SDN controller 202 and a
plurality of routers 204A-204N (collectively, "routers 204"). In
some embodiments, the SDN network 200 is a pure SDN network in
which control plane functionality is provided exclusively by the
centralized SDN controller 202 and data plane functionality is
handled by the routers 204. In some other embodiments, the SDN
network 200 is a hybrid SDN network in which the centralized SDN
controller 202 and the routers 204 share control plane
functionality and the routers 204 provide data plane functionality.
Control plane functionality can include route/re-route
determination, system/device configuration and management, routing
table construction and maintenance, network topology information
exchange, and/or other control plane functionality. For ease of
explanation, the SDN network 200 will be described as a pure SDN
network that controls routing operations performed by the routers
204 via a controller-router interface 206.
[0022] The illustrated centralized SDN controller 202 includes a
control module 208 that provides control plane functionality,
including routing and rerouting in accordance with one or more
routing models 210. The centralized SDN controller 202 can find the
solution shown in FIG. 1C and transition the SDN network 200 from
the congested state shown in FIG. 1B to the congestion resolved
state shown in FIG. 1C via execution, by one or more processors
(best shown in FIGS. 4 and 5), of the control module 208 using the
routing models 210. As described above with respect to FIG. 1C, if
one of the source (headend) routers S1 102A or S2 102B is ordered
to move one of the LSPs 110 to a new path for which the requested
bandwidth exceeds the available bandwidth, a typical rerouting
operation will either fail or preempt lower priority LSPs. To avoid
triggering such exceptions, the centralized SDN controller 202
cannot issue commands to one or more of the routers 204 to reroute
the two LSPs 110A, 110B to the desired new paths in a single step.
Instead, the centralized SDN controller 202 can implement the
routing model(s) 210 to reroute each of the LSPs 110A, 110B to a
new path by requesting only a proportionally small bandwidth for
each LSP (e.g., 1 Gbps in this example) along one or more of the
links 108A-108G utilized by the new path. This ensures that none of
the links 108A-108G will be oversubscribed. After the LSPs 110A,
110B settle on the new paths, the centralized SDN controller 202
can adjust the requested bandwidth for each of the LSPs 110A, 110B
to reach the desired bandwidth and to complete the transition to
the congestion resolved state shown in FIG. 1C.
[0023] The control module 208 can utilize one or more traffic
engineering algorithms to determine when one or more LSPs needs to
be rerouted. Upon determining that one or more LSPs needs to be
rerouted, the centralized SDN controller 202 can execute the
routing model(s) 210 to generate commands directed to the router(s)
204 and can send the commands to the router(s) 204 via the
controller-router interface 206. The router(s) 204 can receive the
commands and perform re-routing operations accordingly.
[0024] It should be understood that requesting a proportionally
small bandwidth during transition does not necessarily cause
notable traffic loss. The actual bandwidth of a given flow can be
greater than the requested value as long as no congestion is
created. When the centralized SDN controller 202 implements the
routing model(s) 210 to reroute the LSPs 110A, 110B to their
respective new paths by requesting only a proportionally small
bandwidth on each LSP (e.g., 1 Gbps in this example), there exists
a possibility of transient overload on certain ones of the links
108A-108G. This is because rerouting operations cannot occur
precisely simultaneously. For example, in a situation involving two
flows--flow 1 (F.sub.1) and flow 2 (F.sub.2)--and when F.sub.1 is
moved away from a certain link and F.sub.2 is moved on to that
link, at time T.sub.1, the link carries F.sub.1; at time T.sub.2,
F.sub.2 is rerouted to the link; and at time T.sub.3, F.sub.1 is
routed away from the link. In this example, between time T.sub.2
and time T.sub.3, the link carries both flows (F.sub.1 and F.sub.2)
and can be temporarily overloaded. This overloading can be solved
using two methods. The temporary overloading is usually rare and
happens in highly congested networks and likely causes only traffic
delay. Nevertheless, it can be avoided or minimized by reducing
either the chance of overloading or the duration. The first method
is to have a processor optimize the order of rerouting with the
lowest traffic flows first. The second method is to employ multiple
simultaneous rerouting to minimize the transition period.
[0025] Turning now to FIG. 3, a method 300 for deadlock free
traffic rerouting in the SDN network 200 will be described,
according to an illustrative embodiment. It should be understood
that the operations of the methods disclosed herein are not
necessarily presented in any particular order and that performance
of some or all of the operations in an alternative order(s) is
possible and is contemplated. The operations have been presented in
the demonstrated order for ease of description and illustration.
Operations may be added, omitted, and/or performed simultaneously,
without departing from the scope of the concepts and technologies
disclosed herein.
[0026] It also should be understood that the methods disclosed
herein can be ended at any time and need not be performed in its
entirety. Some or all operations of the methods, and/or
substantially equivalent operations, can be performed by execution
of computer-readable instructions included on a computer storage
media, as defined herein. The term "computer-readable
instructions," and variants thereof, as used herein, is used
expansively to include routines, applications, application modules,
program modules, programs, components, data structures, algorithms,
and the like. Computer-readable instructions can be implemented on
various system configurations including single-processor or
multiprocessor systems, minicomputers, mainframe computers,
personal computers, hand-held computing devices,
microprocessor-based, programmable consumer electronics,
combinations thereof, and the like.
[0027] Thus, it should be appreciated that the logical operations
described herein are implemented (1) as a sequence of computer
implemented acts or program modules running on a computing system
and/or (2) as interconnected machine logic circuits or circuit
modules within the computing system. The implementation is a matter
of choice dependent on the performance and other requirements of
the computing system. Accordingly, the logical operations described
herein are referred to variously as states, operations, structural
devices, acts, or modules. These states, operations, structural
devices, acts, and modules may be implemented in software, in
firmware, in special purpose digital logic, and any combination
thereof. As used herein, the phrase "cause a processor to perform
operations" and variants thereof is used to refer to causing a
processor of one or more cloud environments, computing systems,
devices, engines, controllers, or components disclosed herein to
perform operations. It should be understood that the performance of
one or more operations may include operations executed by one or
more virtual processors at the instructions of one or more of the
aforementioned hardware processors.
[0028] The method 300 begins and proceeds to operation 302, where
the centralized SDN controller 202 determines that one or more
packet flows are to be rerouted to one or more new paths. The
centralized SDN controller 202 can determine that a given packet
flow should be rerouted if that packet flow causes, at least in
part, congestion on one or more links in a given network, such as
in the example shown in FIG. 1B.
[0029] From operation 302, the method 300 proceeds to operation
304, where the centralized SDN controller 202 reroutes the flow(s)
to the new path(s) determined at operation 302. The centralized SDN
controller 202, at operation 304, also requests bandwidth on each
new path to avoid bandwidth oversubscription on any links traversed
by the flow(s). For a given link with a total bandwidth (e.g., 100
Gbps), the centralized SDN controller 202 can determine a
proportionally small bandwidth to request, such as a given
percentage of the total bandwidth (e.g., 1% for the given link
would yield a proportionally small bandwidth of 1 Gbps).
[0030] From operation 304, the method 300 proceeds to operation
306, where the flow(s) settle on the new path(s). In other words,
all packets associated with the flow(s) are moving through the new
path(s). From operation 306, the method 300 proceeds to operation
308, where the centralized SDN controller 202 adjusts the requested
bandwidth of each flow to a desired value (i.e., full bandwidth) to
complete rerouting. From operation 308, the method 300 proceeds to
operation 310, where the method 300 ends.
[0031] Turning now to FIG. 4, an illustrative cloud environment 400
will be described, according to an illustrative embodiment. The
cloud environment 400 includes a physical environment 402, a
virtualization layer 404, and a virtual environment 406. While no
connections are shown in FIG. 4, it should be understood that some,
none, or all of the components illustrated in FIG. 4 can be
configured to interact with one another to carry out various
functions described herein. In some embodiments, the components are
arranged so as to communicate via one or more networks. Thus, it
should be understood that FIG. 4 and the remaining description are
intended to provide a general understanding of a suitable
environment in which various aspects of the embodiments described
herein can be implemented, and should not be construed as being
limiting in any way.
[0032] The physical environment 402 provides hardware resources,
which, in the illustrated embodiment, include one or more physical
compute resources 408, one or more physical memory resources 410,
and one or more other physical resources 412. The physical compute
resource(s) 408 can include one or more hardware components that
perform computations to process data and/or to execute
computer-executable instructions of one or more application
programs, one or more operating systems, and/or other software. In
some embodiments, the centralized SDN controller 202 and/or one or
more of the routers 204 can be implemented, at least in part, by
the physical compute resources 408. The physical compute resources
408 can include one or more central processing units ("CPUs")
configured with one or more processing cores. The physical compute
resources 408 can include one or more graphics processing unit
("GPU") configured to accelerate operations performed by one or
more CPUs, and/or to perform computations to process data, and/or
to execute computer-executable instructions of one or more
application programs, one or more operating systems, and/or other
software that may or may not include instructions particular to
graphics computations. In some embodiments, the physical compute
resources 408 can include one or more discrete GPUs. In some other
embodiments, the physical compute resources 408 can include CPU and
GPU components that are configured in accordance with a
co-processing CPU/GPU computing model, wherein the sequential part
of an application executes on the CPU and the
computationally-intensive part is accelerated by the GPU processing
capabilities. The physical compute resources 408 can include one or
more system-on-chip ("SoC") components along with one or more other
components, including, for example, one or more of the physical
memory resources 410, and/or one or more of the other physical
resources 412. In some embodiments, the physical compute resources
408 can be or can include one or more SNAPDRAGON SoCs, available
from QUALCOMM of San Diego, Calif.; one or more TEGRA SoCs,
available from NVIDIA of Santa Clara, Calif.; one or more
HUMMINGBIRD SoCs, available from SAMSUNG of Seoul, South Korea; one
or more Open Multimedia Application Platform ("OMAP") SoCs,
available from TEXAS INSTRUMENTS of Dallas, Tex.; one or more
customized versions of any of the above SoCs; and/or one or more
proprietary SoCs. The physical compute resources 408 can be or can
include one or more hardware components architected in accordance
with an ARM architecture, available for license from ARM HOLDINGS
of Cambridge, United Kingdom. Alternatively, the physical compute
resources 408 can be or can include one or more hardware components
architected in accordance with an x86 architecture, such an
architecture available from INTEL CORPORATION of Mountain View,
Calif., and others. Those skilled in the art will appreciate the
implementation of the physical compute resources 408 can utilize
various computation architectures, and as such, the physical
compute resources 408 should not be construed as being limited to
any particular computation architecture or combination of
computation architectures, including those explicitly disclosed
herein.
[0033] The physical memory resource(s) 410 can include one or more
hardware components that perform storage/memory operations,
including temporary or permanent storage operations. In some
embodiments, the physical memory resource(s) 410 include volatile
and/or non-volatile memory implemented in any method or technology
for storage of information such as computer-readable instructions,
data structures, program modules, or other data disclosed herein.
Computer storage media includes, but is not limited to, random
access memory ("RAM"), read-only memory ("ROM"), Erasable
Programmable ROM ("EPROM"), Electrically Erasable Programmable ROM
("EEPROM"), flash memory or other solid state memory technology,
CD-ROM, digital versatile disks ("DVD"), or other optical storage,
magnetic cassettes, magnetic tape, magnetic disk storage or other
magnetic storage devices, or any other medium which can be used to
store data and which can be accessed by the physical compute
resources 408.
[0034] The other physical resource(s) 412 can include any other
hardware resources that can be utilized by the physical compute
resources(s) 408 and/or the physical memory resource(s) 410 to
perform operations described herein. The other physical resource(s)
412 can include one or more input and/or output processors (e.g.,
network interface controller or wireless radio), one or more
modems, one or more codec chipset, one or more pipeline processors,
one or more fast Fourier transform ("FFT") processors, one or more
digital signal processors ("DSPs"), one or more speech
synthesizers, and/or the like.
[0035] The physical resources operating within the physical
environment 402 can be virtualized by one or more virtual machine
monitors (not shown; also known as "hypervisors") operating within
the virtualization/control layer 404 to create virtual resources
that reside in the virtual environment 406. The virtual machine
monitors can be or can include software, firmware, and/or hardware
that alone or in combination with other software, firmware, and/or
hardware, creates and manages virtual resources operating within
the virtual environment 406.
[0036] The virtual resources operating within the virtual
environment 406 can include abstractions of at least a portion of
the physical compute resources 408, the physical memory resources
410, and/or the other physical resources 412, or any combination
thereof. In some embodiments, the abstractions can include one or
more virtual machines upon which one or more applications can be
executed. In some embodiments, the centralized SDN controller 202
and/or the routers 204 can be implemented in the virtual
environment 406.
[0037] FIG. 5 is a block diagram illustrating a computer system 500
configured to provide the functionality in accordance with various
embodiments of the concepts and technologies disclosed herein. In
some embodiments, the centralized SDN controller 202 and/or the
routers 204 can be configured, at least in part, like the
architecture of the computer system 500. In some implementations,
the physical environment 402 (illustrated in FIG. 4) includes one
or more computers that are configured like the architecture of the
computer system 500. The computer system 500 may provide at least a
portion of the physical compute resources 408, the physical memory
resources 410, and/or the other physical resources 412. It should
be understood, however, that modification to the architecture may
be made to facilitate certain interactions among elements described
herein.
[0038] The computer system 500 includes a processing unit 502, a
memory 504, one or more user interface devices 506, one or more
input/output ("I/O") devices 508, and one or more network devices
510, each of which is operatively connected to a system bus 512.
The bus 512 enables bi-directional communication between the
processing unit 502, the memory 504, the user interface devices
506, the I/O devices 508, and the network devices 510.
[0039] The processing unit 502 may be a standard central processor
that performs arithmetic and logical operations, a more specific
purpose programmable logic controller ("PLC"), a programmable gate
array, or other type of processor known to those skilled in the art
and suitable for controlling the operation of the server computer.
Processing units are generally known, and therefore are not
described in further detail herein. The physical compute resources
408 (illustrated in FIG. 4) can include one or more processing
units 502.
[0040] The memory 504 communicates with the processing unit 502 via
the system bus 512. In some embodiments, the memory 504 is
operatively connected to a memory controller (not shown) that
enables communication with the processing unit 502 via the system
bus 512. The physical memory resources 410 (illustrated in FIG. 4)
can include one or more instances of the memory 504. The
illustrated memory 504 contains an operating system 514 and one or
more program modules 516. The operating system 514 can include, but
is not limited to, members of the WINDOWS, WINDOWS CE, and/or
WINDOWS MOBILE families of operating systems from MICROSOFT
CORPORATION, the LINUX family of operating systems, the SYMBIAN
family of operating systems from SYMBIAN LIMITED, the BREW family
of operating systems from QUALCOMM CORPORATION, the MAC OS, OS X,
and/or iOS families of operating systems from APPLE CORPORATION,
the FREEBSD family of operating systems, the SOLARIS family of
operating systems from ORACLE CORPORATION, other operating systems,
and the like.
[0041] The program modules 516 may include various software and/or
program modules to perform the various operations described herein.
The program modules 516 and/or other programs can be embodied in
computer-readable media containing instructions that, when executed
by the processing unit 502, perform various operations such as
those described herein. According to embodiments, the program
modules 516 may be embodied in hardware, software, firmware, or any
combination thereof.
[0042] By way of example, and not limitation, computer-readable
media may include any available computer storage media or
communication media that can be accessed by the computer system
500. Communication media includes computer-readable instructions,
data structures, program modules, or other data in a modulated data
signal such as a carrier wave or other transport mechanism and
includes any delivery media. The term "modulated data signal" means
a signal that has one or more of its characteristics changed or set
in a manner as to encode information in the signal. By way of
example, and not limitation, communication media includes wired
media such as a wired network or direct-wired connection, and
wireless media such as acoustic, RF, infrared and other wireless
media. Combinations of the any of the above should also be included
within the scope of computer-readable media.
[0043] Computer storage media includes volatile and non-volatile,
removable and non-removable media implemented in any method or
technology for storage of information such as computer-readable
instructions, data structures, program modules, or other data.
Computer storage media includes, but is not limited to, RAM, ROM,
Erasable Programmable ROM ("EPROM"), Electrically Erasable
Programmable ROM ("EEPROM"), flash memory or other solid state
memory technology, CD-ROM, digital versatile disks ("DVD"), or
other optical storage, magnetic cassettes, magnetic tape, magnetic
disk storage or other magnetic storage devices, or any other medium
which can be used to store the desired information and which can be
accessed by the computer system 500. In the claims, the phrase
"computer storage medium" and variations thereof does not include
waves or signals per se and/or communication media.
[0044] The user interface devices 506 may include one or more
devices with which a user accesses the computer system 500. The
user interface devices 506 may include, but are not limited to,
computers, servers, PDAs, cellular phones, or any suitable
computing devices. The I/O devices 508 enable a user to interface
with the program modules 516. In one embodiment, the I/O devices
508 are operatively connected to an I/O controller (not shown) that
enables communication with the processing unit 502 via the system
bus 512. The I/O devices 508 may include one or more input devices,
such as, but not limited to, a keyboard, a mouse, or an electronic
stylus. Further, the I/O devices 508 may include one or more output
devices, such as, but not limited to, a display screen or a
printer. In some embodiments, the I/O devices 508 can be used for
manual controls for operations to exercise under certain emergency
situations.
[0045] The network devices 510 enable the computer system 500 to
communicate with other networks or remote systems via a network
518. Examples of the network devices 510 include, but are not
limited to, a modem, a radio frequency ("RF") or infrared ("IR")
transceiver, a telephonic interface, a bridge, a router, or a
network card. The network 518 may include a wireless network such
as, but not limited to, a Wireless Local Area Network ("WLAN"), a
Wireless Wide Area Network ("WWAN"), a Wireless Personal Area
Network ("WPAN") such as provided via BLUETOOTH technology, a
Wireless Metropolitan Area Network ("WMAN") such as a WiMAX network
or metropolitan cellular network. Alternatively, the network 518
may be a wired network such as, but not limited to, a Wide Area
Network ("WAN"), a wired Personal Area Network ("PAN"), or a wired
Metropolitan Area Network ("MAN"). The network 518 may be any other
network described herein.
[0046] Turning now to FIG. 6, details of a network 600 are
illustrated, according to an illustrative embodiment. The network
600 includes a cellular network 602, a packet data network 604, for
example, the Internet, and a circuit switched network 606, for
example, a public-switched telephone network ("PSTN"). The cellular
network 602 includes various components such as, but not limited
to, base transceiver stations ("BTSs"), Node-B's or e-Node-B's,
base station controllers ("BSCs"), radio network controllers
("RNCs"), mobile switching centers ("MSCs"), mobile management
entities ("MMEs"), short message service centers ("SMSCs"),
multimedia messaging service centers ("MMSCs"), home location
registers ("HLRs"), home subscriber servers ("HSSs"), visitor
location registers ("VLRs"), charging platforms, billing platforms,
voicemail platforms, GPRS core network components, location service
nodes, an IP Multimedia Subsystem ("IMS"), and the like. The
cellular network 602 also includes radios and nodes for receiving
and transmitting voice, video data, and combinations thereof to and
from radio transceivers, networks, the packet data network 604, and
the circuit switched network 606.
[0047] A mobile communications device 608, such as, for example, a
cellular telephone, a user equipment, a mobile terminal, a PDA, a
laptop computer, a handheld computer, and combinations thereof, can
be operatively connected to the cellular network 602. The cellular
network 602 can be configured as a Global System for Mobile
communications ("GSM") network and can provide data communications
via General Packet Radio Service ("GPRS") and/or Enhanced Data
rates for GSM Evolution ("EDGE"). Additionally, or alternatively,
the cellular network 602 can be configured as a 3G Universal Mobile
Telecommunications Service ("UMTS") network and can provide data
communications via the High-Speed Packet Access ("HSPA") protocol
family, for example, High-Speed Downlink Packet Access ("HSDPA"),
High-Speed Uplink Packet Access ("HSUPA") (also known as Enhanced
Uplink ("EUL")), and HSPA+. The cellular network 602 also is
compatible with 4G mobile communications standards such as
Long-Term Evolution ("LTE"), or the like, as well as evolved and
future mobile standards.
[0048] The packet data network 604 includes various devices, for
example, servers, computers, databases, routers, packet gateways,
and other devices in communication with one another, as is
generally known. The packet data network 604 can be or can include
the SDN network 200. The packet data network 604 alternatively can
provide connectivity to the SDN network 200. The packet data
network 604 devices are accessible via one or more network links.
The servers often store various files that are provided to a
requesting device such as, for example, a computer, a terminal, a
smartphone, or the like. Typically, the requesting device includes
software (a "browser") for executing a web page in a format
readable by the browser or other software. Other files and/or data
may be accessible via "links" in the retrieved files, as is
generally known. In some embodiments, the packet data network 604
includes or is in communication with the Internet. The circuit
switched network 606 includes various hardware and software for
providing circuit switched communications. The circuit switched
network 606 may include, or may be, what is often referred to as a
plain old telephone system ("POTS"). The functionality of a circuit
switched network 606 or other circuit-switched network are
generally known and will not be described herein in detail.
[0049] The illustrated cellular network 602 is shown in
communication with the packet data network 604 and a circuit
switched network 606, though it should be appreciated that this is
not necessarily the case. One or more Internet-capable devices 610,
for example, a PC, a laptop, a portable device, or another suitable
device, can communicate with one or more cellular networks 602, and
devices connected thereto, through the packet data network 604. It
also should be appreciated that the Internet-capable device 610 can
communicate with the packet data network 604 through the circuit
switched network 606, the cellular network 602, and/or via other
networks (not illustrated).
[0050] As illustrated, a communications device 612, for example, a
telephone, facsimile machine, modem, computer, or the like, can be
in communication with the circuit switched network 606, and
therethrough to the packet data network 604 and/or the cellular
network 602. It should be appreciated that the communications
device 612 can be an Internet-capable device, and can be
substantially similar to the Internet-capable device 610. In the
specification, the network is used to refer broadly to any
combination of the networks 602, 604, 606.
[0051] Based on the foregoing, it should be appreciated that
concepts and technologies directed to deadlock-free traffic
rerouting in SDN networks have been disclosed herein. Although the
subject matter presented herein has been described in language
specific to computer structural features, methodological and
transformative acts, specific computing machinery, and
computer-readable media, it is to be understood that the concepts
and technologies disclosed herein are not necessarily limited to
the specific features, acts, or media described herein. Rather, the
specific features, acts and mediums are disclosed as example forms
of implementing the concepts and technologies disclosed herein.
[0052] The subject matter described above is provided by way of
illustration only and should not be construed as limiting. Various
modifications and changes may be made to the subject matter
described herein without following the example embodiments and
applications illustrated and described, and without departing from
the true spirit and scope of the embodiments of the concepts and
technologies disclosed herein.
* * * * *