Otn Tributary Slot
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Tributary Slot Otn. Karamba Casino Review 8. Total Bonus November 14, 2018. 7 + 30 exclusive spins Bonus doesn’t work Lapalingo. Prize pool: 100% deposit bonus up to £100. January 7, 2018. The Optical Transport Network (OTN) Tributary Module 500G, referred to as OTM-500, provides up to. 500Gbps bidirectional bandwidth to the XTC backplane using pluggable TIMs. The OTM-500 contains ten. TIM sub-slots each of which provide support for various tributary interfaces such as SONET, SDH, ODU, OTU, and/or Ethernet.
*Otn Tributary Slot Definition
DWDM networks are not initially digital networks because they provide users with only a few spectral channels, which are only data transmission medium. Also originally DWDM multiplexers perform SDH multiplexer functionality, in consequence of which inherited a number of shortcomings that became apparent with increasing data rates. Optical Transport Network (OTN)
Disadvantages DWDM systems inherited from SDH systems:
* Insufficient effectiveness of FEC codes, taken as SDH standard. This prevents further increase the spectral density of channels in DWDM multiplexers.
* Too ’small’ switching units for backbone networks operating at speeds of 10 and 40 Gb / s. Even the maximum size of the containers VC-4 (140 Mbit / s) are large enough for the unit of STM-multiplexer 256, which must commute up to 256 containers for each of its ports.
* Not taken into account peculiarities of different types of traffic. SDH technology developers took into account only the voice traffic.
To overcome these drawbacks, a new technology aimed optical transport networks (Optical Transport Network, OTN) Hierarchy speeds
Currently three standardized OTN rate, are selected so as to transparently transmit frames STM-16, STM-64 and STM-256, along with service headings. Hierarchy OTN speeds The protocol stack OTN
The protocol stack includes four layers:
* Protocol OPU (Optical Channel Payload Unit - Custom Unit Optical Channel Data);
* Protocol ODU (Optical Channel Data Unit - Optical Channel Data Unit);
* Protocol OTU (Optical Channel Transport Unit - transport block optical channel;
* Optical Channel (Optical Channel, Och). The protocol stack OTN
Optical Channel, Och - This spectrum DWDM channel.
OPU (Optical Channel Payload Unit ) - Responsible for the delivery of data between network users. Engaged encapsulated user data, such as Ethernet or SDH frames, in units OPU, alignment transmission rates of user data blocks and OPU, and on the receiving side extracts user data and transmits them to the user.
ODU (Optical Channel Data Unit) - Just as the OPU protocol operates between the end OTN network nodes. Its functions include multiplexing and demultiplexing unit OPU.
OTU (Optical Channel Transport Unit) - It works between two adjacent nodes OTN network that supports electrical regeneration of the optical signal function, also called function 3R (retiming, reshaping and regeneration). Кадр OTN Leveling of speed
As with other technologies based on the synchronous multiplex the TDM, OTN technology to solve the problem of equalizing rates of user streams to the multiplexer data rate. Alignment mechanism OTN speeds is some hybrid of the mechanism of bit-stuffing PDH technology and mechanism of the positive and negative justification on the basis of indicators used in SDH technology.
The Working of OTN alignment mechanism depends on the load display mode - Synchronous or Asynchronous mode.
Synchronous load mode - OTN multiplexer synchronizes reception and transmission of synchronization pulses which are in the received user data stream.
Asynchronous load mode - OTN multiplexer is synchronized by its own clock source which is independent from the user data.
To equalize the velocities in the OTN frame, two bytes are used:
* Positive Justification Opportunity, PJO;
* Negative Justification Opportunity, NJO. Multiplexing units
ODU multiplexing user data field OPUk is divided block units on the so-called tributary slots (Tributary Slot, TS), which are placed in the data block OPUk-1. OTN multiplexing units Error correction
In the procedure OTN forward error correction (FEC), which uses RS Reed-Solomon code (255,239). This self-correcting code data is encoded in blocks of 255 bytes, 239 bytes of which are user-defined, and 16 bytes are correction code. Reed-Solomon codes allow to correct up to 8 erroneous bytes in a block of 255 bytes, which is a very good performance for the self-correcting code. The use of Reed-Solomon code allows to improve the signal-to-noise power by 5 dB. This effect makes it possible to increase the distance between regenerators network by 20 km or use a less powerful signal transmitters.
The present disclosure relates generally to optical communication systems and methods. More particularly, the present disclosure relates to a in-band communication channel in optical networks that may be used for Software Defined Networking (SDN) applications or the like.
Conventionally, optical networks rely on in-band communication channels for a variety of Operations, Administration, Maintenance, and Provisioning (OAM & P) functions as well as for control plane signaling and the like. Exemplary in-band communication channels include the Data Communication Channel (DCC) in Synchronous Optical Network (SONET) and Synchronous Digital Hierarchy (SDH) and the General Communication Channel (GCC) in Optical Transport Network (OTN). In contrast to SONET/SDH where the DCC has a constant data rate on the order of 1 Mb/s, the GCC data rate depends on the OTN line rate, i.e., Optical channel Data Unit (ODU) data rate. For example, GCC data rate in the case of an Optical channel Data Unit-1 (ODU1) is ˜333 kb/s, for Optical channel Data Unit-2 (ODU2), its data rate is ˜1.3 Mb/s, for Optical channel Data Unit-4 (ODU4), its data rate is ˜13 Mb/s, and the like. In the past with SONET/SDH, the in-band communication channels were first used solely for OAM & P data between nodes and network management. Here, the low data rate of SONET/SDH DCC sufficed. With OTN, the in-band communication channels evolved to also carry control plane signaling in addition to OAM & P data. Here, the higher GCC data rate in OTN allowed the addition of control plane signaling with the OAM & P data.
Additional applications are evolving, such as SDN, which will require additional bandwidth on the in-band communication channels. Specifically, SDN is a centralized control architecture which requires the gathering and backhaul of data from the nodes to a centralized location/server, i.e., “hubbed” traffic flow patterns. It is also expected that SDN will provide a rich suite of flexible applications, such as in combination with Network Functions Virtualization (NFV). The conventional GCC data rate in OTN will have difficulty in handling the hubbed nature of SDN and the evolving bandwidth requirements, in addition to control plane signaling, OAM & P data communication, etc.
Thus, there is a need for a higher rate in-band communication channel. Unattractive options include: 1) the OTN frame could be modified to allow for a higher rate OTN/GCC communication channel, but this is difficult due to standardization; 2) the line frame format (proprietary to each system vendor) could be designed to include a communications channel time slot meaning a higher required line rate, with the requisite required extra link margin; or 3) a dedicated SDN communication channel could be allocated in the client payload, but would consume valuable client/customer transport bandwidth, and such an approach has generally been commercially unacceptable at the transport layer.
Thus, there is a need for a high-capacity in-band communication channel in optical networks.
In an exemplary embodiment, a method, in a first node in an optical network, for providing an in-band communication channel to a second node in the optical network includes adapting one or more client signals into a line signal for transmission to the second node; and utilizing line adaptation bandwidth of the line signal for the in-band communication channel. The method can further include increasing or decreasing a rate of the line signal to trade off link margin for extra capacity in the in-band communication channel, wherein the increasing or decreasing does not affect a rate of the one or more client signals. The in-band communication channel can be operationally independent from the one or more client signals while concurrently being transported together over the line signal. The adapting can allow a rate of the line signal to be independent of rates of the one or more client signals. The method can further include utilizing the in-band communication channel to communicate data to a Software Defined Networking (SDN) controller or through Network Functions Virtualization (NFV) applications. The one or more client signals can be any of Optical channel Transport Unit k (k=0, 1, 2, 3, 4, flex) or OTUk/Cn where C=100×n (n=1, 2, 3, . . . ) and the line signal can be a proprietary Single Vendor Intra-Domain Interface (SV-IaDI) signal. The one or more client signals each can include in-band communication channels through Optical Transport Network (OTN) General Communication Channel (GCC) overhead that is operated concurrently with the in-band communication channel. The in-band communication channels from the one or more client signals can be used for control plane signaling. The in-band communication channel can be at least an order of magnitude greater in capacity than each of the in-band communication channels of the one or more client signals.
In another exemplary embodiment, an optical modem configured to provide a in-band communication channel includes circuitry configured to adapt one or more client signals into a line signal for transmission to another modem; and circuitry configured to utilize line adaptation bandwidth of the line signal for the in-band communication channel. The optical modem can be configured to one of increase a rate of the line signal to trade off link margin for extra capacity in the in-band communication channel or decrease the rate when the in-band communication channel requires less capacity, wherein the increased rate of the line signal does not affect a rate of the one or more client signals. The in-band communication channel can be operationally independent from the one or more client signals while concurrently being transported together over the line signal. The one or more client signals can be adapted to the line signal allowing a rate of the line signal to be independent of rates of the one or more client signals. The optical modem can be configured to utilize the in-band communication channel to communicate data to a Software Defined Networking (SDN) controller. The one or more client signals can be any of Optical channel Transport Unit k (k=0, 1, 2, 3, 4, flex) or OTUk/Cn where C=100×n (n=1, 2, 3, . . . ) and the line signal can be a proprietary Single Vendor Intra-Domain Interface (SV-IaDI) signal. The one or more client signals each can include in-band communication channels through Optical Transport Network (OTN) General Communication Channel (GCC) overhead that is operated concurrently with the in-band communication channel. The in-band communication channels from the one or more client signals can be used for control plane signaling. The in-band communication channel can be at least an order of magnitude greater in capacity than each of the in-band communication channels of the one or more client signals.
In a further exemplary embodiment, a node configured to provide an in-band communication channel in an optical network includes one or more optical modems each including circuitry configured to adapt one or more client signals into a line signal for transmission to another modem, and circuitry configured to utilize line adaptation bandwidth of the line signal for the in-band communication channel; and a controller communicatively coupled to the one or more optical modems, wherein the controller is configured to enable communications between the in-band communication channels. The controller can be configured to communicate with a Software Defined Networking (SDN) controller through the in-band communication channels.
The present disclosure is illustrated and described herein with reference to the various drawings, in which like reference numbers are used to denote like system components/method steps, as appropriate, and in which:
FIG. 1 is a network diagram of an exemplary network with three nodes for describing an in-band communication channel;
FIG. 2 is an atomic function diagram of a line adaptation process, which may be implemented in the modems in the network of FIG. 1;
FIG. 3 is a logical diagram of a line adaptation process, which may be implemented in the modems in the network of FIG. 1;
FIG. 4 is a flow chart of a method for providing an in-band communication channel;
FIG. 5 is a block diagram of an exemplary node for use with the systems and methods described herein;
FIG. 6 is a block diagram of a controller from the node of FIG. 5, to provide control plane processing, SDN communication, OAM & P, and data connectivity between in-band communication channels; and
FIG. 7 is a flow chart illustrates a process for Optical Transport Network (OTN) line adaptation to provide sub-rate granularity and distribution.
In various exemplary embodiments, an in-band communication channel, with higher capacity than existing in-band communication channels, is formed between two optical modems using line adaptation bandwidth. The line adaptation bandwidth is the difference between client bandwidth and line bandwidth. The client bandwidth can be rates based on Optical channel Transport Unit-k (OTUk) where k=2, 3, or 4; Optical channel Transport Unit Cn where C means 100 and n is a multiplier of 100, e.g. OTUC2 is ˜200 Gb/s, OTUC4 is ˜400 Gb/s, etc.; or the like. The line bandwidth can be based on a rate associated with a modem for a proprietary line side (Single Vendor Intra-Domain Interface (SV-IaDI)) and can vary based on baud-rate, modulation format, Soft-Decision Forward Error Correction (SD-FEC), and the like. The line rate adaptation bandwidth previously was idle or null data. Note, as described herein, the line adaptation bandwidth can be described as the difference between the actual client data rate (which is typically fixed at Layer 1 (Time Division Multiplexing (TDM) layer) and the physical operation rate of the associated optical modem carrying the client data (which can vary based on next-generation coherent modems which support flexible modulation and data rates as well as SD-FEC).
In various exemplary embodiments, this line adaptation bandwidth is configured to provide an in-band communication channel, in addition to providing a line rate adaptation function. Accordingly, the in-band communication channel is decoupled from the associated client signal, i.e., not carried in overhead of the associated client signal, but carried concurrently on a same optical signal as the associated client signal. Additionally, the in-band communication channel allows for a “re-sizable” data rate for the communications channel via re-sizing of the line rate, trading off link margin for extra rate/capacity if required, and is operationally independent from any line transport payload protocols (such as OTN, Ethernet, etc.). Operationally independent means the in-band communication channel described herein carries separate data from the client signals, is processed by different circuitry than the client signals, ultimately has a separate destination (for example, the communications channel is destined for the controller in a node whereas the client signals are destined for client ports, a switch, or the like, etc. Note, while operationally independent, the communication channel is transmitted together with the client signals in the line signal. In an exemplary embodiment, the in-band communication channel described herein can support data rates orders of magnitude higher than the current DCC or GCC data channels. Advantageously, the in-band communication channel described herein preserves the full payload capacity for customer/client traffic, is implemented independently from standards activities (i.e., no changes to the client signals), and no link margin is wasted.
Referring to FIG. 1, in an exemplary embodiment, a network diagram illustrates an exemplary network 10 with three nodes 12a, 12b, 12c. The nodes 12a, 12b, 12c are network elements that provide connectivity at one or more of Layers 0, 1, 2, and/or 3. For illustration purposes, the nodes 12a, 12b, 12c are shown with optical modems 14 forming connectivity, namely modems 14a, 14b connect the nodes 12a, 12c and modems 14c, 14d connect the nodes 12a, 12b. The network 10 is illustrated, for example, as an interconnected linear/mesh network, and those of ordinary skill in the art will recognize the network 100 can include other architectures, with additional nodes or with less nodes, with additional network elements and hardware, etc. The network 10 is presented herein as an exemplary embodiment of a network for describing the in-band communication channel.
The nodes 12a, 12b, 12c communicate with one another optically over links 16a, 16b formed by the modems 14. The network 10 can include a control plane 18 operating on and/or between the nodes 12a, 12b, 12c. The control plane 18 includes software, processes, algorithms, etc. that control configurable features of the network 10, such as automating discovery of the nodes 12a, 12b, 12c and other nodes; management of capacity of the links 16a, 16b; port availability on the nodes 12a, 12b, 12c; connectivity between ports; dissemination of topology and bandwidth information between the nodes 12a, 12b, 12c; calculation and creation of paths for connections; network level protection and restoration; and the like. Note, as described herein, the modems 14 can each be considered a port from a control plane perspective, i.e., a port is a logical point associated with a connection in the control plane 18 and the modem 14 is a physical hardware device forming the connection. In an exemplary embodiment, the control plane 18 can be Automatically Switched Optical Network (ASON), Generalized Multiprotocol Label Switching (GMPLS), Optical Signal and Routing Protocol (OSRP) (from Ciena Corporation), or the like. Of course, those of ordinary skill in the art will recognize the network 10 and the control plane 18 can utilize any type control plane for controlling the nodes 12a, 12b, 12c and establishing connections therebetween.
The network 10 can also include a Software Defined Networking (SDN) controller 20. SDN allows management of network services through centralization and abstraction of lower level functionality. This is done by decoupling the system that makes deci
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Tributary Slot Otn. Karamba Casino Review 8. Total Bonus November 14, 2018. 7 + 30 exclusive spins Bonus doesn’t work Lapalingo. Prize pool: 100% deposit bonus up to £100. January 7, 2018. The Optical Transport Network (OTN) Tributary Module 500G, referred to as OTM-500, provides up to. 500Gbps bidirectional bandwidth to the XTC backplane using pluggable TIMs. The OTM-500 contains ten. TIM sub-slots each of which provide support for various tributary interfaces such as SONET, SDH, ODU, OTU, and/or Ethernet.
*Otn Tributary Slot Definition
DWDM networks are not initially digital networks because they provide users with only a few spectral channels, which are only data transmission medium. Also originally DWDM multiplexers perform SDH multiplexer functionality, in consequence of which inherited a number of shortcomings that became apparent with increasing data rates. Optical Transport Network (OTN)
Disadvantages DWDM systems inherited from SDH systems:
* Insufficient effectiveness of FEC codes, taken as SDH standard. This prevents further increase the spectral density of channels in DWDM multiplexers.
* Too ’small’ switching units for backbone networks operating at speeds of 10 and 40 Gb / s. Even the maximum size of the containers VC-4 (140 Mbit / s) are large enough for the unit of STM-multiplexer 256, which must commute up to 256 containers for each of its ports.
* Not taken into account peculiarities of different types of traffic. SDH technology developers took into account only the voice traffic.
To overcome these drawbacks, a new technology aimed optical transport networks (Optical Transport Network, OTN) Hierarchy speeds
Currently three standardized OTN rate, are selected so as to transparently transmit frames STM-16, STM-64 and STM-256, along with service headings. Hierarchy OTN speeds The protocol stack OTN
The protocol stack includes four layers:
* Protocol OPU (Optical Channel Payload Unit - Custom Unit Optical Channel Data);
* Protocol ODU (Optical Channel Data Unit - Optical Channel Data Unit);
* Protocol OTU (Optical Channel Transport Unit - transport block optical channel;
* Optical Channel (Optical Channel, Och). The protocol stack OTN
Optical Channel, Och - This spectrum DWDM channel.
OPU (Optical Channel Payload Unit ) - Responsible for the delivery of data between network users. Engaged encapsulated user data, such as Ethernet or SDH frames, in units OPU, alignment transmission rates of user data blocks and OPU, and on the receiving side extracts user data and transmits them to the user.
ODU (Optical Channel Data Unit) - Just as the OPU protocol operates between the end OTN network nodes. Its functions include multiplexing and demultiplexing unit OPU.
OTU (Optical Channel Transport Unit) - It works between two adjacent nodes OTN network that supports electrical regeneration of the optical signal function, also called function 3R (retiming, reshaping and regeneration). Кадр OTN Leveling of speed
As with other technologies based on the synchronous multiplex the TDM, OTN technology to solve the problem of equalizing rates of user streams to the multiplexer data rate. Alignment mechanism OTN speeds is some hybrid of the mechanism of bit-stuffing PDH technology and mechanism of the positive and negative justification on the basis of indicators used in SDH technology.
The Working of OTN alignment mechanism depends on the load display mode - Synchronous or Asynchronous mode.
Synchronous load mode - OTN multiplexer synchronizes reception and transmission of synchronization pulses which are in the received user data stream.
Asynchronous load mode - OTN multiplexer is synchronized by its own clock source which is independent from the user data.
To equalize the velocities in the OTN frame, two bytes are used:
* Positive Justification Opportunity, PJO;
* Negative Justification Opportunity, NJO. Multiplexing units
ODU multiplexing user data field OPUk is divided block units on the so-called tributary slots (Tributary Slot, TS), which are placed in the data block OPUk-1. OTN multiplexing units Error correction
In the procedure OTN forward error correction (FEC), which uses RS Reed-Solomon code (255,239). This self-correcting code data is encoded in blocks of 255 bytes, 239 bytes of which are user-defined, and 16 bytes are correction code. Reed-Solomon codes allow to correct up to 8 erroneous bytes in a block of 255 bytes, which is a very good performance for the self-correcting code. The use of Reed-Solomon code allows to improve the signal-to-noise power by 5 dB. This effect makes it possible to increase the distance between regenerators network by 20 km or use a less powerful signal transmitters.
The present disclosure relates generally to optical communication systems and methods. More particularly, the present disclosure relates to a in-band communication channel in optical networks that may be used for Software Defined Networking (SDN) applications or the like.
Conventionally, optical networks rely on in-band communication channels for a variety of Operations, Administration, Maintenance, and Provisioning (OAM & P) functions as well as for control plane signaling and the like. Exemplary in-band communication channels include the Data Communication Channel (DCC) in Synchronous Optical Network (SONET) and Synchronous Digital Hierarchy (SDH) and the General Communication Channel (GCC) in Optical Transport Network (OTN). In contrast to SONET/SDH where the DCC has a constant data rate on the order of 1 Mb/s, the GCC data rate depends on the OTN line rate, i.e., Optical channel Data Unit (ODU) data rate. For example, GCC data rate in the case of an Optical channel Data Unit-1 (ODU1) is ˜333 kb/s, for Optical channel Data Unit-2 (ODU2), its data rate is ˜1.3 Mb/s, for Optical channel Data Unit-4 (ODU4), its data rate is ˜13 Mb/s, and the like. In the past with SONET/SDH, the in-band communication channels were first used solely for OAM & P data between nodes and network management. Here, the low data rate of SONET/SDH DCC sufficed. With OTN, the in-band communication channels evolved to also carry control plane signaling in addition to OAM & P data. Here, the higher GCC data rate in OTN allowed the addition of control plane signaling with the OAM & P data.
Additional applications are evolving, such as SDN, which will require additional bandwidth on the in-band communication channels. Specifically, SDN is a centralized control architecture which requires the gathering and backhaul of data from the nodes to a centralized location/server, i.e., “hubbed” traffic flow patterns. It is also expected that SDN will provide a rich suite of flexible applications, such as in combination with Network Functions Virtualization (NFV). The conventional GCC data rate in OTN will have difficulty in handling the hubbed nature of SDN and the evolving bandwidth requirements, in addition to control plane signaling, OAM & P data communication, etc.
Thus, there is a need for a higher rate in-band communication channel. Unattractive options include: 1) the OTN frame could be modified to allow for a higher rate OTN/GCC communication channel, but this is difficult due to standardization; 2) the line frame format (proprietary to each system vendor) could be designed to include a communications channel time slot meaning a higher required line rate, with the requisite required extra link margin; or 3) a dedicated SDN communication channel could be allocated in the client payload, but would consume valuable client/customer transport bandwidth, and such an approach has generally been commercially unacceptable at the transport layer.
Thus, there is a need for a high-capacity in-band communication channel in optical networks.
In an exemplary embodiment, a method, in a first node in an optical network, for providing an in-band communication channel to a second node in the optical network includes adapting one or more client signals into a line signal for transmission to the second node; and utilizing line adaptation bandwidth of the line signal for the in-band communication channel. The method can further include increasing or decreasing a rate of the line signal to trade off link margin for extra capacity in the in-band communication channel, wherein the increasing or decreasing does not affect a rate of the one or more client signals. The in-band communication channel can be operationally independent from the one or more client signals while concurrently being transported together over the line signal. The adapting can allow a rate of the line signal to be independent of rates of the one or more client signals. The method can further include utilizing the in-band communication channel to communicate data to a Software Defined Networking (SDN) controller or through Network Functions Virtualization (NFV) applications. The one or more client signals can be any of Optical channel Transport Unit k (k=0, 1, 2, 3, 4, flex) or OTUk/Cn where C=100×n (n=1, 2, 3, . . . ) and the line signal can be a proprietary Single Vendor Intra-Domain Interface (SV-IaDI) signal. The one or more client signals each can include in-band communication channels through Optical Transport Network (OTN) General Communication Channel (GCC) overhead that is operated concurrently with the in-band communication channel. The in-band communication channels from the one or more client signals can be used for control plane signaling. The in-band communication channel can be at least an order of magnitude greater in capacity than each of the in-band communication channels of the one or more client signals.
In another exemplary embodiment, an optical modem configured to provide a in-band communication channel includes circuitry configured to adapt one or more client signals into a line signal for transmission to another modem; and circuitry configured to utilize line adaptation bandwidth of the line signal for the in-band communication channel. The optical modem can be configured to one of increase a rate of the line signal to trade off link margin for extra capacity in the in-band communication channel or decrease the rate when the in-band communication channel requires less capacity, wherein the increased rate of the line signal does not affect a rate of the one or more client signals. The in-band communication channel can be operationally independent from the one or more client signals while concurrently being transported together over the line signal. The one or more client signals can be adapted to the line signal allowing a rate of the line signal to be independent of rates of the one or more client signals. The optical modem can be configured to utilize the in-band communication channel to communicate data to a Software Defined Networking (SDN) controller. The one or more client signals can be any of Optical channel Transport Unit k (k=0, 1, 2, 3, 4, flex) or OTUk/Cn where C=100×n (n=1, 2, 3, . . . ) and the line signal can be a proprietary Single Vendor Intra-Domain Interface (SV-IaDI) signal. The one or more client signals each can include in-band communication channels through Optical Transport Network (OTN) General Communication Channel (GCC) overhead that is operated concurrently with the in-band communication channel. The in-band communication channels from the one or more client signals can be used for control plane signaling. The in-band communication channel can be at least an order of magnitude greater in capacity than each of the in-band communication channels of the one or more client signals.
In a further exemplary embodiment, a node configured to provide an in-band communication channel in an optical network includes one or more optical modems each including circuitry configured to adapt one or more client signals into a line signal for transmission to another modem, and circuitry configured to utilize line adaptation bandwidth of the line signal for the in-band communication channel; and a controller communicatively coupled to the one or more optical modems, wherein the controller is configured to enable communications between the in-band communication channels. The controller can be configured to communicate with a Software Defined Networking (SDN) controller through the in-band communication channels.
The present disclosure is illustrated and described herein with reference to the various drawings, in which like reference numbers are used to denote like system components/method steps, as appropriate, and in which:
FIG. 1 is a network diagram of an exemplary network with three nodes for describing an in-band communication channel;
FIG. 2 is an atomic function diagram of a line adaptation process, which may be implemented in the modems in the network of FIG. 1;
FIG. 3 is a logical diagram of a line adaptation process, which may be implemented in the modems in the network of FIG. 1;
FIG. 4 is a flow chart of a method for providing an in-band communication channel;
FIG. 5 is a block diagram of an exemplary node for use with the systems and methods described herein;
FIG. 6 is a block diagram of a controller from the node of FIG. 5, to provide control plane processing, SDN communication, OAM & P, and data connectivity between in-band communication channels; and
FIG. 7 is a flow chart illustrates a process for Optical Transport Network (OTN) line adaptation to provide sub-rate granularity and distribution.
In various exemplary embodiments, an in-band communication channel, with higher capacity than existing in-band communication channels, is formed between two optical modems using line adaptation bandwidth. The line adaptation bandwidth is the difference between client bandwidth and line bandwidth. The client bandwidth can be rates based on Optical channel Transport Unit-k (OTUk) where k=2, 3, or 4; Optical channel Transport Unit Cn where C means 100 and n is a multiplier of 100, e.g. OTUC2 is ˜200 Gb/s, OTUC4 is ˜400 Gb/s, etc.; or the like. The line bandwidth can be based on a rate associated with a modem for a proprietary line side (Single Vendor Intra-Domain Interface (SV-IaDI)) and can vary based on baud-rate, modulation format, Soft-Decision Forward Error Correction (SD-FEC), and the like. The line rate adaptation bandwidth previously was idle or null data. Note, as described herein, the line adaptation bandwidth can be described as the difference between the actual client data rate (which is typically fixed at Layer 1 (Time Division Multiplexing (TDM) layer) and the physical operation rate of the associated optical modem carrying the client data (which can vary based on next-generation coherent modems which support flexible modulation and data rates as well as SD-FEC).
In various exemplary embodiments, this line adaptation bandwidth is configured to provide an in-band communication channel, in addition to providing a line rate adaptation function. Accordingly, the in-band communication channel is decoupled from the associated client signal, i.e., not carried in overhead of the associated client signal, but carried concurrently on a same optical signal as the associated client signal. Additionally, the in-band communication channel allows for a “re-sizable” data rate for the communications channel via re-sizing of the line rate, trading off link margin for extra rate/capacity if required, and is operationally independent from any line transport payload protocols (such as OTN, Ethernet, etc.). Operationally independent means the in-band communication channel described herein carries separate data from the client signals, is processed by different circuitry than the client signals, ultimately has a separate destination (for example, the communications channel is destined for the controller in a node whereas the client signals are destined for client ports, a switch, or the like, etc. Note, while operationally independent, the communication channel is transmitted together with the client signals in the line signal. In an exemplary embodiment, the in-band communication channel described herein can support data rates orders of magnitude higher than the current DCC or GCC data channels. Advantageously, the in-band communication channel described herein preserves the full payload capacity for customer/client traffic, is implemented independently from standards activities (i.e., no changes to the client signals), and no link margin is wasted.
Referring to FIG. 1, in an exemplary embodiment, a network diagram illustrates an exemplary network 10 with three nodes 12a, 12b, 12c. The nodes 12a, 12b, 12c are network elements that provide connectivity at one or more of Layers 0, 1, 2, and/or 3. For illustration purposes, the nodes 12a, 12b, 12c are shown with optical modems 14 forming connectivity, namely modems 14a, 14b connect the nodes 12a, 12c and modems 14c, 14d connect the nodes 12a, 12b. The network 10 is illustrated, for example, as an interconnected linear/mesh network, and those of ordinary skill in the art will recognize the network 100 can include other architectures, with additional nodes or with less nodes, with additional network elements and hardware, etc. The network 10 is presented herein as an exemplary embodiment of a network for describing the in-band communication channel.
The nodes 12a, 12b, 12c communicate with one another optically over links 16a, 16b formed by the modems 14. The network 10 can include a control plane 18 operating on and/or between the nodes 12a, 12b, 12c. The control plane 18 includes software, processes, algorithms, etc. that control configurable features of the network 10, such as automating discovery of the nodes 12a, 12b, 12c and other nodes; management of capacity of the links 16a, 16b; port availability on the nodes 12a, 12b, 12c; connectivity between ports; dissemination of topology and bandwidth information between the nodes 12a, 12b, 12c; calculation and creation of paths for connections; network level protection and restoration; and the like. Note, as described herein, the modems 14 can each be considered a port from a control plane perspective, i.e., a port is a logical point associated with a connection in the control plane 18 and the modem 14 is a physical hardware device forming the connection. In an exemplary embodiment, the control plane 18 can be Automatically Switched Optical Network (ASON), Generalized Multiprotocol Label Switching (GMPLS), Optical Signal and Routing Protocol (OSRP) (from Ciena Corporation), or the like. Of course, those of ordinary skill in the art will recognize the network 10 and the control plane 18 can utilize any type control plane for controlling the nodes 12a, 12b, 12c and establishing connections therebetween.
The network 10 can also include a Software Defined Networking (SDN) controller 20. SDN allows management of network services through centralization and abstraction of lower level functionality. This is done by decoupling the system that makes deci
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