U.S. patent application number 13/315730 was filed with the patent office on 2012-03-29 for method and system for proxy a/v bridging on an ethernet switch.
This patent application is currently assigned to BROADCOM CORPORATION. Invention is credited to Michael Johas Teener.
Application Number | 20120076036 13/315730 |
Document ID | / |
Family ID | 40026962 |
Filed Date | 2012-03-29 |
United States Patent
Application |
20120076036 |
Kind Code |
A1 |
Teener; Michael Johas |
March 29, 2012 |
Method and System for Proxy A/V Bridging on an Ethernet Switch
Abstract
Aspects of a system for proxy NV bridging on an Ethernet switch
may include an AV switch enables reception of incoming PDUs from a
legacy device via an AV block network, wherein each incoming PDU
contains an AV stream identifier (which consists of a destination
address and may also consist of a traffic class designation and/or
higher level protocol identifiers). The destination address may
identify a destination AV device within the AV block network. The
AV switch may enable generation of outgoing PDUs by inserting or
modifying a corresponding traffic class designation within each of
the incoming PDUs. The AV switch may enable transmission using a
specific traffic shaping process of each of the outgoing PDUs to a
destination AV device within the AV block network based on the AV
stream identifier and corresponding QoS parameters.
Inventors: |
Teener; Michael Johas;
(Santa Cruz, CA) |
Assignee: |
BROADCOM CORPORATION
IRVINE
CA
|
Family ID: |
40026962 |
Appl. No.: |
13/315730 |
Filed: |
December 9, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12038099 |
Feb 27, 2008 |
8077617 |
|
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13315730 |
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60917870 |
May 14, 2007 |
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Current U.S.
Class: |
370/252 ;
370/389; 370/401 |
Current CPC
Class: |
H04N 21/64322 20130101;
Y02D 30/00 20180101; H04L 2012/2849 20130101; H04N 19/61 20141101;
G09G 2370/10 20130101; H04N 21/43615 20130101; H04L 12/2816
20130101; H04N 9/8042 20130101; H04N 19/176 20141101; H04N 21/43632
20130101; H04N 5/85 20130101; H04L 12/2805 20130101; H04N 7/106
20130101; H04N 21/6373 20130101; Y02D 30/32 20180101; G09G 5/006
20130101; H04N 19/172 20141101 |
Class at
Publication: |
370/252 ;
370/389; 370/401 |
International
Class: |
H04L 12/26 20060101
H04L012/26; H04L 12/56 20060101 H04L012/56 |
Claims
1. A method for communicating data, the method comprising:
receiving at least one incoming protocol data unit via a network,
wherein each of said at least one incoming protocol data unit
comprises a destination address; generating a corresponding at
least one outgoing protocol data unit by inserting a traffic class
designation within each of said at least one incoming protocol data
unit; and transmitting said corresponding at least one outgoing
protocol data unit based on said destination address, said inserted
traffic class designation and/or higher layer protocol
identifiers.
2. The method according to claim 1, comprising generating said
traffic class designation based on a received reservation
message.
3. The method according to claim 2, comprising transmitting said
received reservation message.
4. The method according to claim 1, comprising generating quality
of service descriptors based on said received at least one incoming
protocol data unit.
5. The method according to claim 4, comprising estimating timing
jitter and/or bandwidth in said received at least one incoming
protocol data unit.
6. The method according to claim 5, comprising adjusting said
generated quality of service descriptors based on said estimated
timing jitter and/or bandwidth.
7. The method according to claim 4, comprising generating a
reservation message based on said generated quality of service
descriptors.
8. The method according to claim 7, comprising transmitting said
generated reservation message.
9. The method according to claim 7, comprising generating said
traffic class designation based on said generated reservation
message.
10. A system for communicating data, the system comprising: one or
more circuits that enable reception of at least one incoming
protocol data unit via a network, wherein each of said at least one
incoming protocol data unit comprises a stream identifier; said one
or more circuits enable generation of a corresponding at least one
outgoing protocol data unit by inserting a traffic class
designation within each of said at least one incoming protocol data
unit; and said one or more circuits enable transmission of said
corresponding at least one outgoing protocol data unit based on
said stream identifier and/or said inserted traffic class
designation.
11. The system according to claim 10, wherein said one or more
circuits enable generation of said traffic class designation based
on a received reservation message.
12. The system according to claim 11, wherein said one or more
circuits enable transmission of said received reservation
message.
13. The system according to claim 10, wherein said one or more
circuits enable generation of quality of service descriptors based
on said received at least one incoming protocol data unit.
14. The system according to claim 13, wherein said one or more
circuits enable estimation of timing jitter and/or bandwidth in
said received at least one incoming protocol data unit.
15. The system according to claim 14, wherein said one or more
circuits enable adjustment of said generated quality of service
descriptors based on said estimated timing jitter and/or
bandwidth.
16. The system according to claim 13, wherein said one or more
circuits enable generation of a reservation message based on said
generated quality of service descriptors.
17. The system according to claim 16, wherein said one or more
circuits enable transmission of said generated reservation
message.
18. The system according to claim 16, wherein said one or more
circuits enable generation of said traffic class designation based
on said generated reservation message.
19. A method for communicating data, the method comprising:
receiving a link discovery message via a port; labeling said port
based on the contents of said received link discovery message; and
determining whether a communicating device may utilize AV Bridging
services for transmitting and/or receiving protocol data units via
said port based on said labeling.
20. The method according to claim 19, wherein said communicating
device is enabled to utilize said AV Bridging services via said
port when said link discovery message comprises a
time-synchronization-enabled attribute and an AV-enabled
attribute.
21-30. (canceled)
Description
CROSS-REFERENCE TO RELATED APPLICATIONS/INCORPORATION BY
REFERENCE
[0001] This application makes reference to, claims priority to, and
claims the benefit of U.S. Provisional Application Ser. No.
60/917,870, filed on May 14, 2007, which is hereby incorporated
herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] Certain embodiments of the invention relate to communication
networks. More specifically, certain embodiments of the invention
relate to a method and system for proxy NV bridging on an Ethernet
switch.
BACKGROUND OF THE INVENTION
[0003] A/V Bridging (AVB) comprises a set of specifications, which
define service classes (or AVB services) that enable the transport
of audio/visual (NV) streams (and/or multimedia streams) across an
AVB-enabled network (or AVB network) based on selected quality of
service (QoS) descriptors. Specifications, which enable the
definition of AVB service classes, include the following.
[0004] A specification, which enables a set of AVB-enabled devices
(or AVB devices) within an AVB network to exchange timing
information. The exchange of timing information enables the devices
to synchronize timing to a common system clock, which may be
provided by a selected one of the AVB devices within the AVB
network.
[0005] A specification, which enables an AVB destination device to
register a request for delivery of a specified AV stream from an
AVB source device. In addition, an AVB source device may request
reservation of network resources, which enable the transmission of
a specified AV stream. The Stream Reservation Protocol (SRP)
defined within the specification provides a mechanism by which the
AVB source device may register the request to reserve resources
within the AVB network (such as bandwidth) to enable the
transmission of the specified AV stream. The Multiple Multicast
Registration Protocol (MMRP) may enable an AVB destination device
to register the request for delivery of a specified AV stream.
[0006] A specification, which defines procedures by which AV
streams are transported across the AVB network. These procedures
may include methods for the queuing and/or forwarding of the AV
streams by individual AVB devices within the AVB network.
[0007] A typical AVB network comprises a set of AVB devices, which
are collectively referred to as an AVB block. An AVB network may
comprise wired local area networks (LANs) and/or wireless LANs
(WLANs), for example. Individual AVB devices within the AVB network
may include AVB-enabled endpoint computing devices (such as laptop
computers and WLAN stations), AVB-enabled switching devices (AV
switches) within LANs and AVB-enabled access points (APs) within
WLANs, for example. Within the AVB block, AV destination devices
may request AV streams from AV source devices, which may be
transported across the AVB network within specified latency target
values as determined from the QoS descriptors associated with
delivery of the AV stream.
[0008] Further limitations and disadvantages of conventional and
traditional approaches will become apparent to one of skill in the
art, through comparison of such systems with some aspects of the
present invention as set forth in the remainder of the present
application with reference to the drawings.
BRIEF SUMMARY OF THE INVENTION
[0009] A method and system for proxy A/V bridging on an Ethernet
switch, substantially as shown in and/or described in connection
with at least one of the figures, as set forth more completely in
the claims.
[0010] These and other advantages, aspects and novel features of
the present invention, as well as details of an illustrated
embodiment thereof, will be more fully understood from the
following description and drawings.
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS
[0011] FIG. 1 is a diagram illustrating an exemplary AVB network,
which may be utilized in connection with an embodiment of the
invention.
[0012] FIG. 2 is a diagram illustrating proxy A/V Bridging on an
Ethernet switch, in accordance with an embodiment of the
invention.
[0013] FIG. 3 is a flowchart illustrating exemplary steps for
enabling proxy A/V Bridging on an Ethernet switch, in accordance
with an embodiment of the invention.
[0014] FIG. 4 is a flowchart illustrating exemplary steps for time
synchronizing AV streams at a proxy device, in accordance with an
embodiment of the invention.
[0015] FIG. 5 is a flowchart illustrating exemplary steps for
transporting AV streams from a legacy device to an AVB network via
a proxy AVB-enabled device, in accordance with an embodiment of the
invention.
[0016] FIG. 6 is a flowchart illustrating exemplary steps for
delivery of AV streams to a legacy device to an AVB network via a
proxy AVB-enabled device, in accordance with an embodiment of the
invention.
DETAILED DESCRIPTION OF THE INVENTION
[0017] Certain embodiments of the invention may be found in a
method and system for proxy A/V bridging on an Ethernet switch.
Various embodiments of the invention comprise a method and system
by which non-AVB-enabled devices (or legacy devices) may utilize
AVB services, for the transmission and/or reception of AV streams
via an AVB network, which may not be available to legacy devices
that communicate with conventional AVB networks.
[0018] FIG. 1 is a diagram illustrating an exemplary AVB network,
which may be utilized in connection with an embodiment of the
invention. Referring to FIG. 1, there is shown an AVB block 102, a
legacy switch 132, a hub device 152, an AV device 146 and a
plurality of legacy devices 142, 144 and 154. The AVB block 102 may
comprise a plurality of AV switches 112 and 114, an AV access point
(AP) 116 and a plurality of AV devices 122, 124, 126 and 128.
[0019] The legacy switch 132 may comprise suitable logic, circuitry
and/or code that may enable capabilities associated with
conventional data link layer switching, for example. The legacy
switch 132 may not be configured to provide AVB services and may
therefore be referred to as a non-AVB-enabled device. The legacy
switch 132 may not be configured to enable the reservation of
resources for the delivery of AV streams. The legacy switch 132 may
not be configured to enable the queuing and/or forwarding of AV
streams based on QoS descriptors. In an exemplary Ethernet network,
the legacy switch 132 may enable the transport of Ethernet frames
on a "best effort" QoS basis. With best effort QoS transport, the
latency associated with the transport of a current Ethernet frame
by the legacy switch 132 may differ from the latency associated
with the transport of a subsequent Ethernet frame. When the legacy
switch 132 receives frames from an isochronous AV stream, the
variations in latency may produce unacceptable jitter or delay when
the AV stream is delivered to a destination device.
[0020] The legacy device 142 may comprise suitable logic, circuitry
and/or code that may enable capabilities associated with the
transmission and/or reception of data link layer protocol data
units (PDUs) to or from conventional data link layer networks, such
as conventional Ethernet networks. The legacy device 142 may also
be referred to as a non-AVB-enabled device. In an exemplary
Ethernet network, the legacy device 142 may not be configured to
exchange timing information with other Ethernet devices, or to
synchronize timing to a common system clock with other Ethernet
devices. The legacy device 142 may not be configured to register a
request for the delivery of AV streams via an Ethernet network from
a source device based on QoS descriptors. The legacy devices 144
and 154 may be substantially similar to the legacy device 142.
[0021] The AV switch 112 may comprise suitable logic, circuitry
and/or code to enable AVB services within an AVB network. An
exemplary AV switch 112 may be utilized in a wired LAN. The AV
switch 114 may be substantially similar to the AV switch 112.
[0022] The AV AP 116 may comprise suitable logic, circuitry and/or
code to enable AVB services within an AVB network. An exemplary AV
AP 116 may be utilized in a WLAN and/or LAN.
[0023] The AV device 122 may comprise suitable logic, circuitry
and/or code to utilize AVB services. An exemplary AV device 122 may
comprise a computing device such as a laptop computer and/or WLAN
station. In an exemplary Ethernet network, the AV device 122 may be
configured to exchange timing information with other Ethernet
devices and to synchronize timing to a common system clock with
other Ethernet devices. The AV device 122 may be configured to
register requests for the delivery of AV streams via an AVB network
from a source device based on QoS descriptors. A particular set of
QoS descriptors may be specified based on a traffic class
designation, for example. The AV devices 124, 126, 128 and 146 may
be substantially similar to the AV device 122.
[0024] The hub device 152 may comprise suitable logic, circuitry
and/or code that may enable repeating of signals received from one
interface to other interfaces coupled to the hub device 152. In an
exemplary Ethernet network, the hub device 152 may enable signals
received via the interface 162e to be transmitted via the interface
162f. A typical hub device 152 may enable coupling of a plurality
of interfaces, for example, 4 interfaces, or 8 interfaces.
[0025] In an exemplary mode of operation, the legacy switch 132 may
receive and/or transmit Ethernet frames via interfaces 162a, 162b,
162c and/or 162d, wherein each of the interfaces may be coupled to
a distinct port within the legacy switch 132. The legacy switch 132
may communicate with the AV switch via interface 162a. The legacy
switch 132 may communicate with the legacy device 142 via interface
162b. The legacy switch 132 may communicate with the legacy device
144 via interface 162c. The legacy switch 132 may communicate with
the AV device 146 via interface 162d. The hub device 152 may
communicate with the legacy device via interface 162e. The hub
device 152 may communicate with the AV switch 112 via interface
162f. The hub device 152 may enable communication between the
legacy device 154 and the AV switch 112. In a conventional Ethernet
network, the legacy switch 132 may transfer Ethernet frames
received via one of the interfaces and transmitted via one of the
other interfaces on a best effort QoS basis. The Ethernet frames
may comprise data from one or more AV streams.
[0026] The AV switch 112 may receive and/or transmit Ethernet
frames via interfaces 162a, 162f and 162g, wherein each of the
interfaces may be coupled to a distinct port within the AV switch
112. The AV switch 112 may communicate with the legacy switch 132
via interface 162a. The AV switch 112 may communicate with the hub
device 152 via interface 162f. The AV switch 112 may communicate
with the AV switch 114 via interface 162g. In a conventional AV
network, the AV switch 112 may transfer Ethernet frames received
and/or transmitted via one of the interfaces 162a or 162f on a best
effort QoS basis. The AV switch 112 may utilize AVB services for
the transfer of Ethernet frames received and/or transmitted via the
interface 162g.
[0027] The AV switch 114 may receive and/or transmit Ethernet
frames via interfaces 162g, 162h, 162i and 162j, wherein each of
the interfaces may be coupled to a distinct port within the AV
switch 114. The AV switch 114 may communicate with the AV switch
112 via interface 162g. The AV switch 114 may communicate with the
AV AP 116 via interface 162h. The AV switch 114 may communicate
with the AV device 122 via interface 162i. The AV switch 114 may
communicate with the AV device 126 via interface 162j. The AV
switch 114 may utilize AVB services for the transfer of Ethernet
frames received via one of the interfaces and transmitted via one
of the other interfaces.
[0028] The AV AP 116 may receive and/or transmit Ethernet frames
via interfaces 162h, 162k and 162l, wherein each of the interfaces
may be coupled to a distinct port within the AV AP 116. The AV AP
116 may communicate with the AV switch 114 via interface 162h. The
AV AP 116 may communicate with the AV device 124 via interface
162k. The AV AP 116 may communicate with the AV device 128 via
interface 162l. The AV AP 116 may utilize AVB services for the
transfer of Ethernet frames received via one of the interfaces and
transmitted via one of the other interfaces. The interfaces 162k
and 162l may comprise RF communication channels utilized in WLAN
systems, for example.
[0029] In a conventional AV network, the AV device 146, which is
shown connected to the legacy switch 132 in FIG. 1, may be unable
to utilize AVB services, which may be available to AV devices 122,
124, 126 and 128 within the AV block 102. Similarly, the legacy
devices 142 and 144, which are shown as being connected to the
legacy switch 132 in FIG. 1, and the legacy device 154, which is
shown as being connected to the hub device 152, may also be unable
to utilize AVB services, which may be available to AV devices
within the AV block 102.
[0030] In various embodiments of the invention, an AV switch 112
within the AV block 102 may enable a legacy device 154, which is
outside of the AV block 102, to utilize AVB services. This may
occur when a port on the AV switch 112 communicates with a single
device. As shown in FIG. 1, the port on the AV switch 112, which is
coupled to the interface 162f, may communicate with a single
device, that device being the legacy device 154 (via the hub device
152). In this aspect of the invention, while the legacy device 154
may remain a non-AVB-enabled device, the AV switch 112 may act as a
proxy for the legacy device 154 within the AV block 102, thereby
enabling the utilization of AVB services for the transport of AV
streams, which are transmitted and/or received by the legacy device
154, within the AV block 102.
[0031] FIG. 2 is a diagram illustrating proxy A/V Bridging on an
Ethernet switch, in accordance with an embodiment of the invention.
Referring to FIG. 2, there is shown an AVB block 202, a legacy
switch 132, an AV device 146 and legacy devices 142 and 144. The
AVB block 202 may comprise a plurality of AV switches 112 and 114,
an AV access point (AP) 116, a legacy device 154 and a plurality of
AV devices 122, 124, 126 and 128.
[0032] In comparing FIG. 2, to FIG. 1, FIG. 2 shows a logical
connection between the AV switch 112 and the legacy device 154 via
the interface 162f. In this representation, the AV switch 112 acts
as a proxy for the legacy device 154 within the AV block 202 via
interface 162f, which enables the legacy device 154 to utilize AVB
services within the AV block 202. Consequently, the legacy device
154 is shown as being within the AV block 202 in FIG. 2 via the
logical connection to the interface 162f.
[0033] In various embodiments of the invention, AV devices, AV
switches and/or AV APs associate within an AV block 202 based on
the exchange of discovery protocol (e.g. "Logical Link Discovery
Protocol": LLDP) messages, which may be periodically transmitted
from the respective devices. The discovery protocol messages
describe the attributes of the device, which is sending the
message. For example, the AV device 122 may transmit discovery
protocol messages, which describe the attributes of the AV device
122 via interface 162i. Similarly, the AV device 124 may transmit
discovery protocol messages, which describe the attributes of the
AV device 124 via interface 162k. The AV switch 114 may transmit
discovery protocol messages, which describe the attributes of the
AV switch 114 via interfaces 162g, 162h, 162i and 162j. The AV
switch 112 may receive discovery protocol messages from the AV
switch 114 via interface 162g. The AV AP 116 may receive discovery
protocol messages from the AV switch 114 via interface 162h. The AV
device 122 may receive discovery protocol messages from the AV
switch 114 via the interface 162i. The AV device 126 may receive
discovery protocol messages from the AV switch 114 via interface
162j. The AV switch 114 may receive discovery protocol messages
from the AV switch 122 via interface 162g. The AV switch 114 may
receive discovery protocol messages from the AV AP 116 via
interface 162h. The AV switch 114 may receive discovery protocol
messages from the AV device 122 via interface 162i. The AV switch
114 may receive discovery protocol messages from the AV device 126
via interface 162j.
[0034] An AVB-enabled device may send discovery protocol messages,
which may comprise a "time-synch" capable attribute and an
AV-capable attribute. An AVB-enabled device, which receives a
discovery protocol message, which comprises the time-synch-capable
attribute and AV-capable attribute via a port, may label the port
to be an "AVB" port. At an AV device 122, 124, 126 or 128, the
labeling of the port to be an AVB port may enable the AV device to
utilize AVB services within the AV block 202. At an AV switch 112
or 114, or at an AV AP 116, the labeling of a port as an AVB port
may enable the port to be utilized for AVB services. The AV
devices, which are reachable via the port, may be referred to as
"participating" devices. The participating devices may utilize AVB
services within the AV block 202.
[0035] Within the AV block 202, a plurality of ports at various AV
switches 112 or 114, or at the AV AP 116 may enable the formation
of paths between AV devices within the AV block 202. For example, a
path between the participating AV device 122 and the participating
AV device 124 may comprise interface 162i, the AV switch 114,
interface 162h, the AV AP 116 and the interface 162k. When the
ports located at the AV switch 114, which are connected to the
interfaces 162i and 162h, and the port located at the AV AP 116,
which are connected to the interfaces 162h and 162k are each
labeled to be an AVB port, then a path may exist within the AV
block 202, which may enable the transport of AV streams between the
participating AV device 122 and the participating AV device
124.
[0036] In conventional AVB networks, an AVB-enabled device, which
does not receive a discovery protocol message that comprises the
time-synch-capable attribute and the AV-capable attribute via a
port, may label the port to be a "legacy" port. Labeling of a port
within an AVB-enabled device as a legacy port may disable AVB
services at the port.
[0037] In various embodiments of the invention, however, a legacy
device 154 may send a discovery protocol message to a port located
within an AV switch 112, which comprises a "proxy request"
attribute. In the exemplary AV block 202 shown in FIG. 2, the AV
switch 112 may receive the discovery protocol messages from the
legacy device 154 at a port within the AV switch 112, which is
coupled to the interface 162f. Receipt of the discovery protocol
messages may enable proxy services at the port within the AV switch
112 when the AV switch 112 detects that a single
Ethernet-addressable device is reachable via the port. The AV
switch 112 may determine whether a single Ethernet-addressable
device is reachable via the port by inspecting the source address
fields within received Ethernet frames, for example. When the
Ethernet frames received at a port within the AV switch 112
comprise a source address field, which references a single Ethernet
address, the AV switch 112 may determine that a single
Ethernet-addressable device is reachable via the port.
[0038] By providing proxy services to the legacy device 154, the AV
switch 112 may enable the legacy device 112 to utilize AVB services
within the AV block 202. The legacy device, which is reachable via
the port, may be referred to as a "semi-participating" device. The
semi-participating legacy device 154 may utilize AVB services
within the AV block 202, even if the semi-participating legacy
device 154 is not enabled to request specific AVB services. In this
aspect of the invention, the AV switch 112 may request the AVB
services on behalf of the semi-participating legacy device 154.
[0039] In one aspect of the invention, the AV switch 112 may
provide proxy services on behalf of the legacy device 154 by
enabling time synchronization between the legacy device 154 and the
system clock utilized within the AV block 202. In various
embodiments of the invention, the AV switch 112 may perform the
timing synchronization when the legacy device 154 is acting as a
source device, which transmits AV streams to one or more
destination devices within the AV block 202, for example the AV
device 122.
[0040] In various embodiments of the invention, the proxy AV switch
112 may time synchronize the AV streams transmitted by the legacy
device 154 to the receiving AV device 122 by providing traffic
shaping services for particular AV stream transmitted by the legacy
device 154. The particular AV stream may be determined by a
specific combination of destination address, priority tag, and
higher-level protocol information (e.g., IP port number). The
particular traffic shaping rules may be determined by the QoS
information obtained from a reservation protocol, utilized in
various embodiments of the invention, or by examining the received
traffic and estimating the QoS information. The traffic shaping of
the Ethernet frames may enable the AVB network to transport the
Ethernet frames along a path within the AV block 202 such that the
latency of the transport along the path is within specified latency
target values. For example, the path from the legacy device 154 to
the AV device 122 may comprise interface 162f, the AV switch 112,
interface 162g, the AV switch 114 and interface 162i. Along the
path, the AV switch 112 may utilize the QoS information to
determine the process for the queuing and forwarding of Ethernet
frames received via the interface 162f and forwarded via the
interface 162g. Similarly, the AV switch 114 may utilize the QoS
information to determine the process for the queuing and forwarding
of Ethernet frames received via the interface 162g and forwarded
via the interface 162i.
[0041] Since the legacy device 154 is not synchronized to a common
system clock within the AV block 202, jitter within the AV stream
transmitted from the legacy device 154 to the AV device 122 may be
greater than may be the case when the path is between two AV
devices, for example an AV device 122 which transmits an AV stream
to the AV device 124. In this aspect of the invention, the AV
switch 112 may reduce the jitter in Ethernet frames received from
the legacy device 154, measured at the interface 162f, by providing
the traffic shaping services described above.
[0042] In various embodiments of the invention, in which the legacy
device 154 transmits AV streams which do not utilize AV Bridging
services, for example when legacy device 154 transmits a standard
RTP (real time protocol) stream, the AV stream may be transported
across the AV block 202 utilizing legacy timing mechanisms.
[0043] In another aspect of the invention, the AV switch 112 may
provide proxy services on behalf of the legacy device 154 by
enabling registration of requests for delivery of AV streams from
an AVB source device, when the legacy device 154 is a destination
for the AV stream. When the legacy device 154 is a source for the
AV stream, the AV switch 112 may enable sending of requests for the
reservation of resources within the AV block 202 on behalf of the
legacy device 154.
[0044] When the legacy device 154 is a source for the AV stream,
the AV switch 112 may detect Ethernet frames received from the
legacy device 154. Based on the detections, the AV switch 112 may
generate a traffic profile for the AV streams. For example, the AV
switch 112 may determine that the generated traffic profile for the
received AV stream may correspond to an RTP profile for an MPEG-2
stream. Based on the generated traffic profile, the AV switch 112
may generate a set of reservation parameters, for example QoS
descriptors. The AV switch 112 may then generate a reservation
request message (e.g, "Stream Reservation Protocol": SRP, or
"Multiple Stream Reservation Protocol": MSRP) on behalf of the
legacy device 154, which incorporates the generated set of
reservation parameters. The AV switch 112 may propagate the
generated reservation message among AVB-enabled devices within the
AV block 202.
[0045] In various embodiments of the invention, when the legacy
device 154 is capable of generating a reservation request message
on its own behalf, the legacy device 154 may send the reservation
request message to the AV switch 112 via the interface 162f. When
the legacy device 154 is a semi-participating device, the AV switch
112 may propagate the received reservation message among
AVB-enabled devices within the AV block 202.
[0046] When the legacy device 154 is a destination for the AV
stream, the AV switch 112 may detect Ethernet frames, which are
being forwarded to the legacy device 154. Based on the detections,
the AV switch 112 may generate a traffic profile for the AV
streams. Based on the generated traffic profile, the AV switch 112
may generate a set of QoS descriptors. The AV switch 112 may then
generate a registration request message on behalf of the legacy
device 154, which incorporates the generated set of QoS
descriptors. The AV switch 112 may then propagate the generated
registration request message among AVB-enabled devices within the
AV block 202.
[0047] In various embodiments of the invention, when the legacy
device 154 is capable of generating a registration request message
on its own behalf, the legacy device 154 may send the registration
request message to the AV switch 112 via the interface 162f. When
the legacy device 154 is a semi-participating device, the AV switch
112 may propagate the received registration request message among
AVB-enabled devices within the AV block 202.
[0048] FIG. 3 is a flowchart illustrating exemplary steps for
enabling proxy NV Bridging on an Ethernet switch, in accordance
with an embodiment of the invention. Referring to FIG. 3, in step
302, a discovery protocol message may be received at port within an
AV switch 112. Step 304 may determine whether the discovery
protocol message includes time-synch and AV attributes. When step
304 determines that the attributes may be present in the received
discovery protocol message, in step 306, the switch port may be
labeled an AVB port. In step 308, devices reachable via the port
may be determined to be participating devices within an AVB block
202.
[0049] When step 304 determines that the time-synch and AV
attributes may not be present in the received discovery protocol
message, in step 310, the switch port may be labeled a legacy port.
Step 312 may determine whether a single Ethernet-addressable device
may be reachable via the labeled legacy port. When step 312
determines that more than a single device is reachable via the
labeled legacy port, in step 314, the switch port may be determined
to be not proxy enabled.
[0050] When step 312 determines that a single Ethernet-addressable
device may be reachable via the labeled legacy port, step 316 may
determine whether a proxy request attribute was included in the
received discovery protocol message. When step 316 determines that
a proxy request attribute was not included in the received
discovery protocol message, step 314 may follow.
[0051] When step 316 determines that a proxy request attribute was
included in the discovery protocol message, step 318 may determine
that the switch port is to be proxy enabled. In step 320, the
device reachable via the port may be determined to be a
semi-participating device.
[0052] FIG. 4 is a flowchart illustrating exemplary steps for time
synchronizing AV streams at a proxy device, in accordance with an
embodiment of the invention. Referring to FIG. 4, in step 402 an AV
switch 112 may receive Ethernet frames from a legacy device 154.
The Ethernet frames may comprise portions of an AV stream generated
by an application within the legacy device 154. Step 404 may
determine whether the protocol executing within the legacy device
154 utilizes AVB services. When step 404 determines that the
protocol does not utilize AVB services, in step 406, the AV switch
112 may transport the Ethernet frames using legacy transport
mechanisms.
[0053] When step 404 determines that the protocol does utilize AVB
services, in step 408, the AV switch 112 may transport the Ethernet
frames within the AV block 202 utilizing AVB services. The AV
switch 112 may apply traffic shaping rules specified by the QoS
parameters for the AV stream before transporting the Ethernet
frames within the AV block 202. The AV switch 112 may identify the
AV stream by a destination address and/or higher layer information.
The QoS parameters may be determined based on a reservation
protocol. The QoS parameters may be determined by examining the
received Ethernet frames, which may enable identification of a
potential AV stream and measurement of timing of Ethernet frames
received in the potential AV stream to determine jitter and
bandwidth estimates.
[0054] FIG. 5 is a flowchart illustrating exemplary steps for
transporting AV streams from a legacy device to an AVB network via
a proxy AVB-enabled device, in accordance with an embodiment of the
invention. FIG. 5 presents an exemplary method by which an AV
switch 112 may forward AV streams within an AV block 202, utilizing
AVB services, on behalf of a legacy device 154. In FIG. 5, the
legacy device 154 may be assumed to be a semi-participating device.
Referring to FIG. 5, in step 502, the AV switch 112 may receive
Ethernet frames from the legacy device 154. The Ethernet frames may
comprise portions of data from the AV stream. Step 504 may
determine whether a received Ethernet frame contains a reservation
message. When the AV switch 112 receives a reservation message from
the legacy device 154, in step 508, the AV switch 112 may propagate
the received reservation message within the AV block 202.
[0055] When step 504 determines that the received Ethernet frames
do not contain a reservation message, in step 510, the AV switch
112 may determine whether the legacy device 154 had previously sent
a reservation message. When the AV switch 112 determines, in step
510, that the legacy device 154 had previously sent a reservation
message, in step 512, the AV switch 112 may transport the received
Ethernet frames within the AV block 202 using AVB services. The AV
switch 112 may provide traffic shaping services for the Ethernet
frames before transporting the Ethernet frames within the AV block
202. The AV switch 112 may also insert a traffic class designation
or change an existing traffic class designation within the Ethernet
frames prior to transporting the Ethernet frames within the AV
block 202.
[0056] When the AV switch 112 determines, in step 510, that the
legacy device had not previously sent a reservation message, in
step 514, the AV switch 112 may detect AV streams and estimate QoS
descriptors based on the headers and content of Ethernet frames
received from the legacy device 154. The estimated QoS descriptors
may account for jitter and bandwidth usage detected in the received
Ethernet frames from the legacy device 154. In step 516, the AV
switch 112 may generate a reservation message on behalf of the
legacy device 154 based on the estimated QoS descriptors. In step
518, the AV switch 112 may propagate the generated SRP reservation
message within the AV block 202.
[0057] FIG. 6 is a flowchart illustrating exemplary steps for
delivery of AV streams to a legacy device to an AVB network via a
proxy AVB-enabled device, in accordance with an embodiment of the
invention. FIG. 6 presents an exemplary method by which an AV
switch 112 may utilize AVB services to forward AV streams from an
AVB-enabled device within an AV block 202 to a legacy device 154.
In FIG. 6, the legacy device 154 may be assumed to be a
semi-participating device. Referring to FIG. 6, in step 602, the AV
switch 112 may receive Ethernet frames, which are addressed for
delivery to the legacy device 154. The Ethernet frames may comprise
portions of data from the AV stream. In step 604, the received
Ethernet frames may be forwarded to the legacy device 154. Step 606
may determine whether the AV switch 112 has received a registration
request message (e.g: "Multiple Multicast Registration Protocol":
MMRP) from the legacy device 154. When the AV switch 112
determines, in step 606, that a registration request message has
been received from the legacy device 154, in step 610, the AV
switch 112 may propagate the received registration request message
within the AV block 202.
[0058] When the AV switch 112 determines, in step 606, that a
registration request message has not been received from the legacy
device 154, in step 612, the AV switch 112 may estimate QoS
descriptors based on the Ethernet frames forwarded to the legacy
device 154. In step 614, the AV switch 112 may generate a
registration request message on behalf of the legacy device 154. In
step 616, the AV switch 112 may propagate the generated
registration request message within the AV block 202.
[0059] Aspects of a system for proxy A/V bridging on an Ethernet
switch may comprise an AV switch 112, which enables reception of
incoming PDUs from a legacy device 154 via an AV block network 202,
wherein each incoming PDU contains an AV stream identifier. The AV
stream identifier consists of a destination address, traffic class
identifier, and may also include a higher level protocol identifier
(such as IP port number). The destination address may identify a
destination AV device 122 within the AV block network 202. The AV
switch 112 may enable generation of outgoing PDUs by inserting or
modifying a corresponding traffic class designation within each of
the incoming PDUs. The AV switch 112 may enable transmission of
each of the outgoing PDUs to a destination AV device 122 within the
AV block network 202 based on the AV stream identifier.
[0060] The AV switch 112 enables generation or modification of the
corresponding traffic class designation based on a reservation
message received from the legacy device 154. The AV switch 112 may
enable transmission to propagate the received reservation message
within the AV block network 202.
[0061] The AV switch 112 may enable generation of QoS descriptors
based on the incoming PDUs received from the legacy device 154. The
AV switch 112 may enable estimation of timing jitter and bandwidth
of the received AV streams, where the AV streams may be identified
based on address, traffic class, and/or higher level identifiers of
incoming PDUs. The generated QoS descriptors may be adjusted based
on the estimated timing jitter and bandwidth. The AV switch 112 may
enable generation of a reservation message for an AV stream based
on the generated QoS descriptors. The AV switch 112 may enable
transmission to propagate the generated reservation message within
the AV block network 202. The AV switch 112 may enable generation
or modification of the corresponding traffic class designation
based on the generated reservation message.
[0062] Aspects of a system for proxy NV bridging on an Ethernet
switch may comprise an AV switch 112 receiving discovery protocol
messages via a port. The AV switch may label the port based on the
contents of the received discovery protocol message. The AV switch
112 may determine whether a communicating device, such as a legacy
device 154, may utilize AVB services for transmitting and/or
receiving PDUs via the port based on the labeling.
[0063] The communicating device may be enabled to utilize AVB
services via the port when the discovery protocol message comprises
a time-synchronization-enabled attribute and an AV-enabled
attribute. The port may be labeled as a legacy port when the
discovery protocol message does not comprise a
time-synchronization-enabled attribute and an AV-enabled attribute.
When the port is labeled as a legacy port, a legacy device 154 may
be enabled to utilize AVB services via the port when the discovery
protocol message comprises a proxy request attribute. The port may
be labeled as a proxy enabled port when the discovery protocol
message comprises the proxy request attribute. A single legacy
device 154 may transmit and/or receive PDUs via the labeled proxy
enabled port.
[0064] Another embodiment of the invention may provide a
machine-readable storage, having stored thereon, a computer program
having at least one code section executable by a machine, thereby
causing the machine to perform the steps as described herein for
proxy A/V bridging on an Ethernet switch.
[0065] Accordingly, the present invention may be realized in
hardware, software, or a combination of hardware and software. The
present invention may be realized in a centralized fashion in at
least one computer system, or in a distributed fashion where
different elements are spread across several interconnected
computer systems. Any kind of computer system or other apparatus
adapted for carrying out the methods described herein is suited. A
typical combination of hardware and software may be a
general-purpose computer system with a computer program that, when
being loaded and executed, controls the computer system such that
it carries out the methods described herein.
[0066] The present invention may also be embedded in a computer
program product, which comprises all the features enabling the
implementation of the methods described herein, and which when
loaded in a computer system is able to carry out these methods.
Computer program in the present context means any expression, in
any language, code or notation, of a set of instructions intended
to cause a system having an information processing capability to
perform a particular function either directly or after either or
both of the following: a) conversion to another language, code or
notation; b) reproduction in a different material form.
[0067] While the present invention has been described with
reference to certain embodiments, it will be understood by those
skilled in the art that various changes may be made and equivalents
may be substituted without departing from the scope of the present
invention. In addition, many modifications may be made to adapt a
particular situation or material to the teachings of the present
invention without departing from its scope. Therefore, it is
intended that the present invention not be limited to the
particular embodiment disclosed, but that the present invention
will include all embodiments falling within the scope of the
appended claims.
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