CN107786908B - Method and device for establishing path - Google Patents
Method and device for establishing path Download PDFInfo
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- CN107786908B CN107786908B CN201610753704.5A CN201610753704A CN107786908B CN 107786908 B CN107786908 B CN 107786908B CN 201610753704 A CN201610753704 A CN 201610753704A CN 107786908 B CN107786908 B CN 107786908B
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Abstract
The invention discloses a method and a device for establishing a path, which comprises the following steps: a path calculation unit acquires color light port parameters of client layer equipment at two ends; establishing a first optical path between two boundary nodes in an optical transmission network domain according to the parameter information of the optical transmission network and the optical wavelength range supported by the client layer equipment at two ends; acquiring a light path parameter, and determining whether the light path parameter meets the constraint condition of a black link of an optical transmission network; if the constraint condition is not met, deleting the first light path and establishing a second light path until a light path with the light-emitting path parameter meeting the constraint condition is established; after a light path with light path parameters meeting constraint conditions is established, judging whether parameters of black link ports of client layer equipment at two ends meet the constraint condition range or not; if the constraint range is satisfied, the optical path between end-to-end is determined for the two-end client layer device.
Description
Technical Field
The present invention relates to the field of communications, and in particular, to a method and an apparatus for establishing a path.
Background
In a conventional optical Transport Network (Transport Network), communication signals on a User Network Interface (UNI) between one client layer device (e.g., a transmitter (Tx) and a receiver (Rx) from vendors B and D, etc. shown in fig. 1) and another client layer device at a distance are carried by the optical Transport device. Devices on the User Network Interface-client (UNI-C) side are typically connected to interfaces of transport Network devices via optical interfaces. The User Network Interface-Network (UNI-N) side converts the client signal into a Dense Wavelength Division Multiplexing (DWDM) Wavelength meeting the transmission equipment requirement through optical-electrical-optical (OEO) conversion, and then performs subsequent processing on the optical signal. At the receiving end, the transmitting device then converts the DWDM optical signal to a white light signal by OEO conversion for delivery to the customer layer device.
In some network deployment scenes, the color light port can be directly deployed on equipment on the UNI-C side, so that cost and power consumption can be effectively saved. The so-called color port, that is, the interface of the client layer device connected to the optical layer device, can output an interface of specific wavelengths, which may be transmitted over the optical transport network directly through wavelength division multiplexing without optical-electrical conversion, and the international telecommunication union telecommunication standards institute (ITU-T) g.698.2 proposes a scenario in which the color port is deployed on a UNI-C side device, as shown in fig. 2, where Tx is a transmitter, Rx is a receiver, Ss is a source reference point, and Rs is a destination reference point.
According to the description of the existing Internet Engineering Task Force Wavelength Switched Optical Network (IETF WSON, Internet Engineering Task Force Wavelength Switched Optical Network) standard, Wavelength constraint conditions of a transmitter and a receiver, Forward Error Correction codes (FEC) and the like need to be considered when a path passing through an Optical transport Network is established through a control plane. In addition, when a path is established, the existing WSON scheme only considers the problem of end-to-end wavelength continuity, but does not consider the problem of the range of optical parameters related to the optical network of the transmission plane, that is, only each node passing along the path is considered, and the node has a corresponding available wavelength, so that the path which actually meets the wavelength continuity condition is not necessarily a qualified optical path, and the problem that the path is unusable due to a large error rate may occur.
In a scene that the UNI-C side device interface is a color interface, the client layer device and the optical transport device belong to different management domains, the domain where the client layer device is located cannot know the path calculation information of the service layer network, and the prior art does not support diffusing the path calculation information of the client layer to the service layer or diffusing the path calculation information of the service layer to the client layer, so that a path passing through the optical transport network cannot be established at present.
For the above situation, the industry proposes a solution for controlling and managing an optical interface, and referring to the network deployment scenario shown in fig. 3, the domain where B1, B2, and B3 are located is an optical management domain, and includes a Path Computation Element (PCE) for computing an end-to-end Path; a1, A3 belong to one customer domain, C1, C3 belong to another separate customer domain, and D1 is a node in a third separate customer domain. In these three domains, the interface where a1 connects to B1 is a color light port, the interface where C1 connects to B3 is a color light port, and the interface where D1 connects to B2 is a color light port. In this network scenario, the PCE/network manager of the optical transport network may acquire the parameter information of the color interface connected to the optical transport network by the client network in a unicast manner, that is, may acquire the parameter information of the color interfaces a1, D1, and C1.
For the above network scenario, the solution in the industry is to obtain parameter Information of the client network color interface through Management Information Base (MIB) Information of the network manager, and to complete control of the client network color interface and the optical transport network through the MIB. The industry does not provide a solution for centralized path computation and distributed signaling for the control plane.
Disclosure of Invention
In order to solve the above technical problem, embodiments of the present invention provide a method and an apparatus for establishing a path, so as to implement establishment of a path traversing an optical transport network in a black link scenario.
The embodiment of the invention provides a method for establishing a path, which comprises the following steps:
a path calculation unit acquires color light port parameters of client layer equipment at two ends;
establishing a first optical path between two boundary nodes in an optical transmission network domain according to parameter information of the optical transmission network and an optical wavelength range supported by the client layer equipment at the two ends, wherein the two boundary nodes are respectively connected to the client layer equipment at the two ends;
acquiring a light path parameter, and determining whether the light path parameter meets the constraint condition of a black link of an optical transmission network; if the constraint condition is not met, deleting the first light path and establishing a second light path until a light path with light-emitting path parameters meeting the constraint condition is established;
after establishing the optical path with the optical path parameters meeting the constraint conditions, judging whether the parameters of the black link ports of the client layer equipment at the two ends meet the constraint condition range; and if the constraint condition range is met, determining an optical path between end to end for the two-end client layer equipment.
In the foregoing solution, if the constraint condition range is satisfied, determining an end-to-end optical path for the two-end client layer device includes:
and if the constraint condition range is met, determining an optical path between end to end for the client layer equipment at the two ends in a stitching mode.
In the foregoing solution, the acquiring a light path parameter includes:
receiving a light path parameter reported by a monitoring point of a transmission plane, wherein the light path parameter is obtained by monitoring a currently established light path by the monitoring point of the transmission plane.
In the above scheme, acquiring color light interface parameters of client layer devices at two ends includes:
acquiring color optical interface parameters summarized by a light path source node through a calling mechanism, wherein the summarized color optical interface parameters refer to: the source node acquires the color light port parameter of the destination node by using the notification message, and summarizes the color light port parameter of the destination node and the color light port parameter of the source node.
In the above scheme, the method further comprises:
and receiving the exchanged color optical interface parameters sent by the source node, wherein the exchanged color optical interface parameters are color optical interface parameters of the two-end client layer equipment exchanged by using notification messages when the source node collects.
In the above scheme, the method further comprises:
expanding a signaling message in advance, wherein the signaling message carries parameter information required by path calculation of a tail end target reference point;
wherein, the carried parameter information comprises: wavelength range information supported by the tail end color interface, FEC information supported by the tail end color interface, segment maximum bit error rate information, maximum/minimum input power supported by the tail end color interface, minimum optical signal-to-noise ratio information, maximum reflectance information of a receiver, tolerance information of an optical receiver, and application code information supported by the tail end.
In the above scheme, the application code information includes: maximum supported spectral width information, supported channel spacing information, whether a dispersion compensation mechanism is supported, supported optical branch signal rate and modulation format information, whether an optical amplifier is present, supported fiber type information, whether FEC information is used.
In the above scheme, the method further comprises:
when receiving the color optical interface parameter of the destination node sent by the optical path source node, the color optical interface parameter of the source node sent by the optical path source node is also received, and the color optical interface parameter of the source node includes: wavelength range information supported by the head-end color light interface, FEC information supported by the head-end color light interface, section maximum error rate information, maximum/minimum output power supported by the head-end color light interface, minimum side mode suppression ratio, minimum channel extinction ratio, eye mask effect related parameters and application code information supported by the head-end node.
In the above scheme, the application code information includes: maximum supported spectral width information, supported channel spacing information, whether a dispersion compensation mechanism is supported, supported optical branch signal rate and modulation format information, whether an optical amplifier is present, supported fiber type information, whether FEC information is used.
In the foregoing solution, the path calculating unit is a stateful path calculating unit, and accordingly, the method further includes:
the stateful path calculation unit calculates a first optical path according to the acquired parameter information of the optical transmission network and the optical wavelength range supported by the client layer equipment at the two ends, and then sends the first optical path to a path starting boundary node in the optical transmission network through a path calculation unit protocol (PCEP) mechanism;
after the Path starting boundary node completes the Path establishment, the stateful Path Computation Element obtains optical parameters measured by a source node and a destination node of the optical transport network through a Path Computation Element Protocol (PCEP).
In the above scheme, the optical parameters include:
maximum ripple, maximum/minimum dispersion of the path, minimum optical return loss of the source reference point, maximum discrete reflection between the source reference point and the destination reference point, maximum dgd, maximum polarization dependent loss, maximum inter-channel crosstalk of the destination reference point, maximum interferometer crosstalk of the destination node, maximum optical path optical signal-to-noise ratio cost.
An embodiment of the present invention further provides a device for establishing a path, where the device includes:
the first acquisition unit is used for acquiring color light port parameters of client layer equipment at two ends;
a computing unit, configured to establish a first optical path between two border nodes in an optical transport network domain according to parameter information of the optical transport network and an optical wavelength range supported by the two end client layer devices, where the two border nodes are connected to the two end client layer devices respectively;
a second obtaining unit for obtaining the optical path parameter;
a judging unit, configured to determine whether the optical path parameter satisfies a constraint condition of a black link of an optical transport network;
the calculation unit is further configured to delete the first light path and establish a second light path until a light path with a light exit path parameter meeting the constraint condition is established when the constraint condition is not met;
the judging unit is further configured to judge whether parameters of black link ports of the client layer devices at the two ends meet a constraint condition range after a light path with light exit path parameters meeting the constraint condition is established;
the computing unit is further configured to determine an end-to-end optical path for the two-end client layer device if the constraint condition range is satisfied.
In the foregoing solution, the computing unit is further configured to determine an optical path between end to end for the two end customer layer devices in a stitching manner when the constraint condition range is satisfied.
In the foregoing solution, the second obtaining unit is further configured to receive a light path parameter reported by a monitoring point of a transport plane, where the light path parameter is obtained by monitoring a currently established light path by the monitoring point of the transport plane.
In the foregoing solution, the first obtaining unit is further configured to obtain a color optical interface parameter summarized by the optical path source node through a call mechanism, where the summarized color optical interface parameter refers to: the source node acquires the color light port parameter of the destination node by using the notification message, and summarizes the color light port parameter of the destination node and the color light port parameter of the source node.
In the foregoing solution, the first obtaining unit is further configured to receive an exchanged color optical interface parameter sent by a source node, where the exchanged color optical interface parameter is a color optical interface parameter exchanged between the two end client layer devices by using a notification message when the source node performs summarization.
In the above scheme, the calculating unit is further configured to expand a signaling message in advance, where the signaling message carries parameter information required for performing path calculation on a tail-end target reference point;
wherein, the carried parameter information comprises: wavelength range information supported by the tail end color interface, FEC information supported by the tail end color interface, segment maximum bit error rate information, maximum/minimum input power supported by the tail end color interface, minimum optical signal-to-noise ratio information, maximum reflectance information of a receiver, tolerance information of an optical receiver, and application code information supported by the tail end.
In the above scheme, the application code information includes: maximum supported spectral width information, supported channel spacing information, whether a dispersion compensation mechanism is supported, supported optical branch signal rate and modulation format information, whether an optical amplifier is present, supported fiber type information, whether FEC information is used.
In the foregoing solution, the first obtaining unit is further configured to, when receiving a color optical interface parameter of a destination node sent by a light path source node, further receive a color optical interface parameter of a source node sent by the light path source node, where the color optical interface parameter of the source node includes: wavelength range information supported by the head-end color light interface, FEC information supported by the head-end color light interface, section maximum error rate information, maximum/minimum output power supported by the head-end color light interface, minimum side mode suppression ratio, minimum channel extinction ratio, eye mask effect related parameters and application code information supported by the head-end node.
In the above scheme, the application code information includes: maximum supported spectral width information, supported channel spacing information, whether a dispersion compensation mechanism is supported, supported optical branch signal rate and modulation format information, whether an optical amplifier is present, supported fiber type information, whether FEC information is used.
In the above scheme, the apparatus further comprises: the sending unit is used for sending the first optical path to a path starting boundary node in the optical transmission network through a PCEP mechanism after the first optical path is calculated;
the second obtaining unit is further configured to, after the path starting boundary node completes path establishment, obtain, by the stateful path computing unit, optical parameters measured by a source node and a destination node of the optical transport network through a PCEP protocol.
In the above scheme, the optical parameters include:
maximum ripple, maximum/minimum dispersion of the path, minimum optical return loss of the source reference point, maximum discrete reflection between the source reference point and the destination reference point, maximum dgd, maximum polarization dependent loss, maximum inter-channel crosstalk of the destination reference point, maximum interferometer crosstalk of the destination node, maximum optical path optical signal-to-noise ratio cost.
In the technical scheme of the embodiment of the invention, a PCE acquires color optical interface parameters of client layer equipment at two ends; the PCE establishes a first optical path between two boundary nodes in an optical transmission network domain according to parameter information of the optical transmission network and an optical wavelength range supported by the two end client layer devices, wherein the two boundary nodes are respectively connected to the two end client layer devices; the PCE acquires a light path parameter and determines whether the light path parameter meets the constraint condition of a black link of an optical transmission network; if the constraint condition is not met, deleting the first light path and establishing a second light path until a light path with light-emitting path parameters meeting the constraint condition is established; after establishing the optical path with the optical path parameters meeting the constraint conditions, the PCE judges whether the parameters of the black link ports of the client layer equipment at the two ends meet the constraint condition range; and if the constraint condition range is met, determining an optical path between end to end for the two-end client layer equipment. By adopting the scheme of the embodiment of the invention, the problem that the existing control plane scheme can not be applied to the black link scene can be effectively solved, and the problem that the existing WSON scheme is not available in practice although the path is successfully established when being applied to the scene is also solved, thereby realizing the establishment of the path crossing the optical transport network in the black link scene.
Drawings
The drawings illustrate generally, by way of example, but not by way of limitation, various embodiments discussed herein.
FIG. 1 is a diagram of a conventional multi-vendor DWDM network architecture;
FIG. 2 is a block diagram of a multi-vendor DWDM utilizing black links;
FIG. 3 is a network deployment scenario diagram;
FIG. 4 is a flowchart illustrating a method for establishing a path according to an embodiment of the present invention;
FIG. 5 is a schematic view of a wavelength range information sub-object;
FIG. 6 is a flow chart of path establishment;
FIG. 7 is a diagram illustrating TLV format carried by the PCEP protocol;
fig. 8 is a schematic structural diagram of a device for establishing a path according to an embodiment of the present invention.
Detailed Description
So that the manner in which the features and aspects of the embodiments of the present invention can be understood in detail, a more particular description of the embodiments of the invention, briefly summarized above, may be had by reference to the embodiments, some of which are illustrated in the appended drawings.
Fig. 4 is a flowchart illustrating a method for establishing a path according to an embodiment of the present invention, where the method for establishing a path in this example is applied in a PCE, and as shown in fig. 4, the method for establishing a path includes the following steps:
step 401: and acquiring color light port parameters of client layer equipment at two ends.
Here, the client layer device refers to a transmitter (Tx) and a receiver (Rx) from a certain vendor. Communication signals between the client layer devices on one end and the client layer devices on the other end are carried on the optical transport device. The two-end client layer device indicates the one-end client layer device and the other-end client layer device that are to establish the optical path.
In the embodiment of the invention, the client layer equipment sends the parameters of the color optical ports (specifically the optical interface parameters of the color optical ports) of the client layer equipment at two ends to the PCE, and requests the PCE to establish a light path spanning an optical transmission network.
In the embodiment of the present invention, the acquiring parameters of color light ports of client layer devices at two ends includes:
acquiring color optical interface parameters summarized by a light path source node through a calling mechanism, wherein the summarized color optical interface parameters refer to: the source node acquires the color light port parameter of the destination node by using the notification message, and summarizes the color light port parameter of the destination node and the color light port parameter of the source node.
In the embodiment of the present invention, the method further includes:
and receiving the exchanged color optical interface parameters sent by the source node, wherein the exchanged color optical interface parameters are color optical interface parameters of the two-end client layer equipment exchanged by using notification messages when the source node collects.
Step 402: according to the parameter information of the optical transmission network and the optical wavelength range supported by the client layer equipment at the two ends, a first optical path between two boundary nodes is established in the optical transmission network domain, and the two boundary nodes are respectively connected to the client layer equipment at the two ends.
Specifically, the PCE first performs path computation according to parameter information of the optical transport network obtained by route flooding and an optical wavelength range supported by the client layer devices at the two ends, and establishes a path between two corresponding boundary nodes connected to the client layer devices at the two ends in the optical transport network domain, which is called a first optical path.
Step 403: acquiring a light path parameter, and determining whether the light path parameter meets the constraint condition of a black link of an optical transmission network; if the constraint condition is not satisfied, deleting the first light path and establishing a second light path until establishing a light path with the light-emitting path parameter meeting the constraint condition.
In an embodiment of the present invention, the acquiring a light path parameter includes:
receiving a light path parameter reported by a monitoring point of a transmission plane, wherein the light path parameter is obtained by monitoring a currently established light path by the monitoring point of the transmission plane.
Specifically, after the first path is successfully established, the monitoring point of the transport plane acquires the optical path parameter monitored by the monitoring point, and reports the optical path parameter to the PCE. The PCE receives a light path parameter reported by a monitoring point of a transmission plane, wherein the light path parameter is obtained by monitoring a currently established light path by the monitoring point of the transmission plane.
After determining that the optical path parameters meet the relevant requirements of a Black Link (Black Link) of an optical transport network, the PCE determines whether the optical path parameters meet constraint conditions according to color optical port parameters received by the PCE, and if so, determines that an end-to-end optical path can be established; if the constraint condition is not met, deleting the first optical path established before, then establishing a second optical path different from the previous optical path, and repeating the monitoring and reporting steps until an optical path meeting the constraint condition is determined.
Step 404: after establishing the optical path with the optical path parameters meeting the constraint conditions, judging whether the parameters of the black link ports of the client layer equipment at the two ends meet the constraint condition range; and if the constraint condition range is met, determining an optical path between end to end for the two-end client layer equipment.
In this embodiment of the present invention, if the constraint condition range is satisfied, determining an end-to-end optical path for the two-end client layer device includes:
and if the constraint condition range is met, determining an optical path between end to end for the client layer equipment at the two ends in a stitching mode.
Specifically, after determining that the optical path parameters meet the constraint conditions, the PCE evaluates whether the parameters of the black link ports of the client layer devices at the two ends meet the corresponding constraint condition range, and if so, determines an end-to-end optical path for the client layer devices at the two ends in a stitching manner.
In the embodiment of the present invention, the method further includes:
a signaling message (such as a LINK _ CAPABILITY object) in a Routing requirement document (RFC) Used for Path Calculation 4974 is expanded in advance, and the signaling message carries parameter information required by Path Calculation of a tail-end target reference point;
wherein, the carried parameter information comprises: wavelength range information supported by the tail end color interface, FEC information supported by the tail end color interface, segment maximum bit error rate information, maximum/minimum input power supported by the tail end color interface, minimum optical signal-to-noise ratio information, maximum reflectance information of a receiver, tolerance information of an optical receiver, and application code information supported by the tail end.
In the above scheme, the application code information includes: maximum supported spectral width information, supported channel spacing information, whether a dispersion compensation mechanism is supported, supported optical branch signal rate and modulation format information, whether an optical amplifier is present, supported fiber type information, whether FEC information is used.
In the embodiment of the present invention, the method further includes:
when receiving the color optical interface parameter of the destination node sent by the optical path source node, the color optical interface parameter of the source node sent by the optical path source node is also received, and the color optical interface parameter of the source node includes: wavelength range information supported by the head-end color light interface, FEC information supported by the head-end color light interface, section maximum error rate information, maximum/minimum output power supported by the head-end color light interface, minimum side mode suppression ratio, minimum channel extinction ratio, eye mask effect related parameters and application code information supported by the head-end node.
In the above scheme, the application code information includes: maximum supported spectral width information, supported channel spacing information, whether a dispersion compensation mechanism is supported, supported optical branch signal rate and modulation format information, whether an optical amplifier is present, supported fiber type information, whether FEC information is used.
In the embodiment of the present invention, the PCE must be a stateful PCE.
The stateful PCE calculates a first optical path according to the acquired parameter information of the optical transport network and the optical wavelength range supported by the client layer equipment at the two ends, and then sends the first optical path to a path starting boundary node in the optical transport network through a PCEP mechanism;
after the path starting boundary node completes the path establishment, the stateful PCE acquires optical parameters measured by a source node and a destination node of the optical transport network through a PCEP protocol.
In the above scheme, the optical parameters include:
maximum ripple, maximum/minimum dispersion of the path, minimum optical return loss of the source reference point, maximum discrete reflection between the source reference point and the destination reference point, maximum dgd, maximum polarization dependent loss, maximum inter-channel crosstalk of the destination reference point, maximum interferometer crosstalk of the destination node, maximum optical path optical signal-to-noise ratio cost.
The method for establishing a path according to the embodiment of the present invention is further described in detail below with reference to specific application scenarios.
Specifically, as shown in the network deployment scenario of fig. 3, it is assumed that a path from a3 to C3 is to be established, and the steps are as follows:
1) because A3 to a1, C1 to C3 are client layer network paths, and a1 to C1 paths are optical layer paths, a1 to C1 paths exist as service layer paths to carry A3 to C3 client layer paths; as shown in fig. 6, A3 first initiates a Path (Path) message of client layer signaling, a destination node is C3, A3 sends the Path message to next-hop node a1, as shown in step 1 in the figure, a1 blocks the signaling flow of the client layer first because its next hop is an optical network, and a1 then initiates the signaling flow of the service layer to establish a Path from a1 to C1.
2) A1 firstly determines that the interface connected to the optical network is the color light interface on UNI-C side and the color light interface on the opposite end is on C1 node, then firstly operates the call mechanism defined in RFC4974 to gather the optical interface constraint information of the client layer equipment on the two ends, and acquires the parameter information supported by the tail end destination reference point color light interface through the LINK _ CAPABILITY object of RSVP-TE signaling. Specifically, as shown in steps 2 and 3 in fig. 6, the node a1 first sends a signaling request message to the node C1 through the control channel, requesting to acquire parameter information supported by the corresponding optical interface of the node C1; after receiving the signaling request message, the C1 returns the parameter information supported by the own black link interface to the a1 node through a signaling response message.
The parameters carried include: wavelength range information supported by a color interface of the tail end client, supported FEC information, segment maximum bit error rate information, supported maximum and minimum input power, minimum optical signal-to-noise ratio information, maximum reflectance information of a receiver, tolerance information of an optical receiver, and application code information supported by the tail end.
Wherein the application code information includes: maximum supported spectral width information, supported channel spacing information, whether a dispersion compensation mechanism is supported, supported optical branch signal rate and modulation format information, whether an optical amplifier is present, supported optical fiber type information, and whether FEC information is used.
For each parameter information, a sub-object may be used to carry, and the sub-object follows the format of the signaling sub-object, specifically, the supported wavelength range information sub-object shown in fig. 5.
The link management protocol defined in the existing standard is operated between the a1 and B1 nodes, and between the C1 and B3 nodes, before the signaling interaction step in the present invention is used, the link management protocol is needed to be used first to complete the attribute negotiation of the color interface between the client layer node and the service layer node.
3) After summarizing the parameter information supported by the color light interface of the tail end destination reference point, the A1 combines the color light interface parameter information supported by the self source node reference point. Specifically, as shown in 4 steps in fig. 6, the PCE of the optical transport network performs path computation of an a1 optical interface-optical transport network-C1 optical interface. The color light interface parameter information supported by the source reference point and the destination reference point is carried in an extended interface attribute object in the PCReq message, and the format of the interface attribute object is defined according to the PCEP protocol. The object includes a plurality of Type Length Values (TLVs) for carrying parameter information of color ports supported by the source reference point and the destination reference point, as shown in fig. 7. For some other supported attributes, it can be represented by using multiple fields to carry a list.
The parameters carried are: the optical parameter information supported by the color optical interface of the source node specifically includes: wavelength range information supported by a head end customer color light port, supported FEC information, section maximum error rate information, supported maximum and minimum output power, minimum side mode suppression ratio, minimum channel extinction ratio, eye mask effect related parameters and application code information supported by a head end node.
Wavelength range information supported by a color interface of the tail end client, supported FEC information, segment maximum bit error rate information, supported maximum and minimum input power, minimum optical signal-to-noise ratio information, maximum reflectance information of a receiver, tolerance information of an optical receiver, and application code information supported by the tail end.
Wherein the application code information includes: maximum supported spectral width information, supported channel spacing information, whether a dispersion compensation mechanism is supported, supported optical branch signal rate and modulation format information, whether an optical amplifier is present, supported optical fiber type information, and whether FEC information is used.
4) After receiving the path computation request sent by a1, the PCE of the optical transport network determines that the PCE is a network scenario of a black link by analyzing the network scenario, and then computes a path from B1 to B3 according to conditions such as wavelength continuity constraints by using the function of the stateful PCE. The path calculation process firstly carries out some preprocessing, including comparing wavelength ranges supported by the first destination node, selecting the wavelength ranges supported by the first destination node, and then considering the wavelength supported by the intermediate transmission network node; and comparing the supported modulation formats, FEC and fiber types, selecting the types available for both the source node and the destination node, and calculating a path from B1 to B3.
Then sends a path initiation setup message to the B1 node, specifically requesting to set up an end-to-end optical transport network path from B1 to B3, as shown in fig. 6, 5. This establishes an optical transport network path B1 to B3 in the optical transport network through the signaling flow, as shown in fig. 6 by step 6.
5) After the path from B1 to B3 is established, (wavelength constraint is used to calculate a path, and a path is established), optical parameters related to some optical transport network paths are monitored and measured by B1 and B3 nodes through some optical devices of the transport plane, and reported to the stateful PCE through PCEP protocol messages, specifically as shown in steps 7 and 8 in fig. 6, and these parameter information is carried in the extended TLV of the LSPA object. Parameters carried in the LSPA object include: maximum ripple, maximum and minimum dispersion of a path, minimum optical return loss of a source reference point, maximum discrete reflection between the source reference point and a destination reference point, maximum differential group delay, maximum polarization dependent loss, maximum inter-channel crosstalk of the destination reference point, maximum interferometer crosstalk of a destination node, and maximum optical path optical signal-to-noise ratio cost.
And for the data which can be monitored by the destination node, the destination node reports the data through the PCNtf notification message. The PCNtf notification message carries the LSP-ID to identify the path to be monitored.
The PCE determines whether the parameters of the optical paths meet the constraint conditions according to the parameter information of the customer network color light port received by the PCE, and if so, determines that an end-to-end optical path can be established; if the constraint condition is not met, deleting the previously established path, then establishing a path different from the previous path, and repeating the just monitoring and reporting steps, namely repeating the steps 5, 6, 7 and 8 in fig. 6 until determining an optical transport network path meeting the parameter constraint condition.
6) After determining that the parameters of the optical path meet the constraint conditions, the PCE evaluates whether the parameters of the black link ports at the two ends meet the corresponding constraint condition range, and if so, establishes an end-to-end optical path of the service layer for a1 to C1 in an RSVP-TE signaling stitching manner.
7) And after the optical layer path of the service layer is established, the existing technology is used for completing the establishment of the whole path from A3 to C3.
Fig. 8 is a schematic structural diagram of a device for establishing a path according to an embodiment of the present invention, and as shown in fig. 8, the device for establishing a path includes:
a first obtaining unit 81, configured to obtain color light interface parameters of client layer devices at two ends;
a calculating unit 82, configured to establish a first optical path between two border nodes in an optical transport network domain according to parameter information of the optical transport network and an optical wavelength range supported by the two end client layer devices, where the two border nodes are connected to the two end client layer devices respectively;
a second obtaining unit 83 for obtaining the optical path parameters;
a determining unit 84, configured to determine whether the optical path parameter satisfies a constraint condition of a black link of an optical transport network;
the calculating unit 82 is further configured to delete the first light path and establish a second light path until a light path with a light exit path parameter meeting the constraint condition is established when the constraint condition is not met;
the determining unit 84 is further configured to determine whether parameters of the black link ports of the client layer devices at the two ends meet a constraint condition range after a light path whose light exit path parameters meet the constraint condition is established;
the calculating unit 82 is further configured to determine an end-to-end optical path for the two-end client layer device if the constraint condition range is satisfied.
In this embodiment of the present invention, the calculating unit 82 is further configured to determine an optical path between end to end for the two end client layer devices by means of stitching when the constraint condition range is satisfied.
In this embodiment of the present invention, the second obtaining unit 83 is further configured to receive a light path parameter reported by a monitoring point of a transport plane, where the light path parameter is obtained by monitoring a currently established light path by the monitoring point of the transport plane.
In this embodiment of the present invention, the first obtaining unit 81 is further configured to obtain a color optical interface parameter summarized by the optical path source node through a call mechanism, where the summarized color optical interface parameter refers to: the source node acquires the color light port parameter of the destination node by using the notification message, and summarizes the color light port parameter of the destination node and the color light port parameter of the source node.
In this embodiment of the present invention, the first obtaining unit 81 is further configured to receive an exchanged color optical interface parameter sent by a source node, where the exchanged color optical interface parameter is a color optical interface parameter that is exchanged between the two client layer devices by using a notification message when the source node performs summarization.
In this embodiment of the present invention, the calculating unit 82 is further configured to expand a signaling message in advance, where the signaling message carries parameter information required for performing path calculation on a tail-end target reference point;
wherein, the carried parameter information comprises: wavelength range information supported by the tail end color interface, FEC information supported by the tail end color interface, segment maximum bit error rate information, maximum/minimum input power supported by the tail end color interface, minimum optical signal-to-noise ratio information, maximum reflectance information of a receiver, tolerance information of an optical receiver, and application code information supported by the tail end.
In this embodiment of the present invention, the application code information includes: maximum supported spectral width information, supported channel spacing information, whether a dispersion compensation mechanism is supported, supported optical branch signal rate and modulation format information, whether an optical amplifier is present, supported fiber type information, whether FEC information is used.
In this embodiment of the present invention, the first obtaining unit 81 is further configured to, when receiving a color optical interface parameter of a destination node sent by a light path source node, further receive a color optical interface parameter of a source node sent by the light path source node, where the color optical interface parameter of the source node includes: wavelength range information supported by the head-end color light interface, FEC information supported by the head-end color light interface, section maximum error rate information, maximum/minimum output power supported by the head-end color light interface, minimum side mode suppression ratio, minimum channel extinction ratio, eye mask effect related parameters and application code information supported by the head-end node.
In this embodiment of the present invention, the application code information includes: maximum supported spectral width information, supported channel spacing information, whether a dispersion compensation mechanism is supported, supported optical branch signal rate and modulation format information, whether an optical amplifier is present, supported fiber type information, whether FEC information is used.
In the embodiment of the present invention, the apparatus further includes: the sending unit is used for sending the first optical path to a path starting boundary node in the optical transmission network through a PCEP mechanism after the first optical path is calculated;
the second obtaining unit 83 is further configured to, after the path starting boundary node completes the path establishment, obtain, by the stateful path computing unit 82, the optical parameters measured by the source node and the destination node of the optical transport network through the PCEP protocol.
In an embodiment of the present invention, the optical parameters include:
maximum ripple, maximum/minimum dispersion of the path, minimum optical return loss of the source reference point, maximum discrete reflection between the source reference point and the destination reference point, maximum dgd, maximum polarization dependent loss, maximum inter-channel crosstalk of the destination reference point, maximum interferometer crosstalk of the destination node, maximum optical path optical signal-to-noise ratio cost.
Those skilled in the art will understand that the functions implemented by each unit in the apparatus for establishing a path shown in fig. 8 can be understood by referring to the related description of the method for establishing a path. The functions of the units in the apparatus for establishing a path shown in fig. 8 may be implemented by a program running on a processor, or may be implemented by specific logic circuits.
As will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of a hardware embodiment, a software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, optical storage, and the like) having computer-usable program code embodied therein.
The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention.
Claims (22)
1. A method of establishing a path, the method comprising:
a path calculation unit acquires color light port parameters of client layer equipment at two ends;
establishing a first optical path between two boundary nodes in an optical transmission network domain according to parameter information of the optical transmission network and an optical wavelength range supported by the client layer equipment at the two ends, wherein the two boundary nodes are respectively connected to the client layer equipment at the two ends;
acquiring a light path parameter, and determining whether the light path parameter meets the constraint condition of a black link of an optical transmission network; if the constraint condition is not met, deleting the first light path and establishing a second light path until a light path with light-emitting path parameters meeting the constraint condition is established;
after establishing the optical path with the optical path parameters meeting the constraint conditions, judging whether the parameters of the black link ports of the client layer equipment at the two ends meet the constraint condition range; and if the constraint condition range is met, determining an optical path between end to end for the two-end client layer equipment.
2. The method for establishing a path according to claim 1, wherein the determining a light path between end to end for the two-end customer layer device if the constraint condition range is satisfied comprises:
and if the constraint condition range is met, determining an optical path between end to end for the client layer equipment at the two ends in a stitching mode.
3. The method of claim 1, wherein the obtaining optical path parameters comprises:
receiving a light path parameter reported by a monitoring point of a transmission plane, wherein the light path parameter is obtained by monitoring a currently established light path by the monitoring point of the transmission plane.
4. The method for establishing a path according to claim 1, wherein the obtaining parameters of the color interface of the two-end client layer device comprises:
acquiring color optical interface parameters summarized by a light path source node through a calling mechanism, wherein the summarized color optical interface parameters refer to: the source node acquires the color light port parameter of the destination node by using the notification message, and summarizes the color light port parameter of the destination node and the color light port parameter of the source node.
5. The method for establishing a path according to claim 4, further comprising:
and receiving the exchanged color optical interface parameters sent by the source node, wherein the exchanged color optical interface parameters are color optical interface parameters of the two-end client layer equipment exchanged by using notification messages when the source node collects.
6. The method for establishing a path according to claim 1, further comprising:
expanding a signaling message in advance, wherein the signaling message carries parameter information required by path calculation of a tail end target reference point;
wherein, the carried parameter information comprises: wavelength range information supported by the tail end color interface, forward error correction FEC information supported by the tail end color interface, segment maximum bit error rate information, maximum/minimum input power supported by the tail end color interface, minimum optical signal to noise ratio information, maximum reflectance information of a receiver, tolerance information of an optical receiver and application code information supported by the tail end.
7. The method for establishing a path according to claim 6, wherein the application code information comprises: maximum supported spectral width information, supported channel spacing information, whether a dispersion compensation mechanism is supported, supported optical branch signal rate and modulation format information, whether an optical amplifier is present, supported fiber type information, whether FEC information is used.
8. The method for establishing a path according to claim 4, further comprising:
when receiving the color optical interface parameter of the destination node sent by the optical path source node, the color optical interface parameter of the source node sent by the optical path source node is also received, and the color optical interface parameter of the source node includes: wavelength range information supported by the head-end color light interface, FEC information supported by the head-end color light interface, section maximum error rate information, maximum/minimum output power supported by the head-end color light interface, minimum side mode suppression ratio, minimum channel extinction ratio, eye mask effect related parameters and application code information supported by the head-end node.
9. The method for establishing a path according to claim 8, wherein the application code information comprises: maximum supported spectral width information, supported channel spacing information, whether a dispersion compensation mechanism is supported, supported optical branch signal rate and modulation format information, whether an optical amplifier is present, supported fiber type information, whether FEC information is used.
10. The method for establishing a path according to claim 1, wherein the path computation element is a stateful path computation element, and accordingly, the method further comprises:
the stateful path calculation unit calculates a first optical path according to the acquired parameter information of the optical transmission network and the optical wavelength range supported by the client layer equipment at the two ends, and then sends the first optical path to a path starting boundary node in the optical transmission network through a path calculation unit protocol (PCEP) mechanism;
after the path starting boundary node completes the path establishment, the stateful path computing unit obtains optical parameters measured by a source node and a destination node of the optical transport network through a PCEP protocol.
11. The method of establishing a path of claim 10, wherein the optical parameters comprise:
maximum ripple, maximum/minimum dispersion of the path, minimum optical return loss of the source reference point, maximum discrete reflection between the source reference point and the destination reference point, maximum dgd, maximum polarization dependent loss, maximum inter-channel crosstalk of the destination reference point, maximum interferometer crosstalk of the destination node, maximum optical path optical signal-to-noise ratio cost.
12. An apparatus for establishing a path, the apparatus comprising:
the first acquisition unit is used for acquiring color light port parameters of client layer equipment at two ends;
a computing unit, configured to establish a first optical path between two border nodes in an optical transport network domain according to parameter information of the optical transport network and an optical wavelength range supported by the two end client layer devices, where the two border nodes are connected to the two end client layer devices respectively;
a second obtaining unit for obtaining the optical path parameter;
a judging unit, configured to determine whether the optical path parameter satisfies a constraint condition of a black link of an optical transport network;
the calculation unit is further configured to delete the first light path and establish a second light path until a light path with a light exit path parameter meeting the constraint condition is established when the constraint condition is not met;
the judging unit is further configured to judge whether parameters of black link ports of the client layer devices at the two ends meet a constraint condition range after a light path with light exit path parameters meeting the constraint condition is established;
the computing unit is further configured to determine an end-to-end optical path for the two-end client layer device if the constraint condition range is satisfied.
13. The apparatus according to claim 12, wherein the computing unit is further configured to determine an end-to-end optical path for the two-end customer layer device by means of stitching if the constraint range is satisfied.
14. The apparatus according to claim 12, wherein the second obtaining unit is further configured to receive a light path parameter reported by a monitoring point of a transport plane, wherein the light path parameter is obtained by monitoring a currently established light path by the monitoring point of the transport plane.
15. The apparatus according to claim 12, wherein the first obtaining unit is further configured to obtain a color optical interface parameter summarized by a light path source node through a call mechanism, where the summarized color optical interface parameter refers to: the source node acquires the color light port parameter of the destination node by using the notification message, and summarizes the color light port parameter of the destination node and the color light port parameter of the source node.
16. The apparatus according to claim 15, wherein the first obtaining unit is further configured to receive an exchanged color optical interface parameter sent by a source node, where the exchanged color optical interface parameter is a color optical interface parameter exchanged between the two end client layer devices by using a notification message when the source node performs aggregation.
17. The apparatus according to claim 12, wherein the calculating unit is further configured to expand a signaling message in advance, and the signaling message carries parameter information required for path calculation for a tail-end destination reference point;
wherein, the carried parameter information comprises: wavelength range information supported by the tail end color interface, FEC information supported by the tail end color interface, segment maximum bit error rate information, maximum/minimum input power supported by the tail end color interface, minimum optical signal-to-noise ratio information, maximum reflectance information of a receiver, tolerance information of an optical receiver, and application code information supported by the tail end.
18. The apparatus for establishing a path according to claim 17, wherein the application code information comprises: maximum supported spectral width information, supported channel spacing information, whether a dispersion compensation mechanism is supported, supported optical branch signal rate and modulation format information, whether an optical amplifier is present, supported fiber type information, whether FEC information is used.
19. The apparatus according to claim 15, wherein the first obtaining unit is further configured to, when receiving a color optical interface parameter of a destination node sent by a source node of an optical path, further receive a color optical interface parameter of the source node sent by the source node of the optical path, where the color optical interface parameter of the source node includes: wavelength range information supported by the head-end color light interface, FEC information supported by the head-end color light interface, section maximum error rate information, maximum/minimum output power supported by the head-end color light interface, minimum side mode suppression ratio, minimum channel extinction ratio, eye mask effect related parameters and application code information supported by the head-end node.
20. The apparatus for establishing a path according to claim 19, wherein the application code information comprises: maximum supported spectral width information, supported channel spacing information, whether a dispersion compensation mechanism is supported, supported optical branch signal rate and modulation format information, whether an optical amplifier is present, supported fiber type information, whether FEC information is used.
21. The apparatus for establishing a path according to claim 12, further comprising: the sending unit is used for sending the first optical path to a path starting boundary node in the optical transmission network through a PCEP mechanism after the first optical path is calculated;
the second obtaining unit is further configured to, after the path starting boundary node completes path establishment, obtain, by the stateful path computing unit, optical parameters measured by a source node and a destination node of the optical transport network through a PCEP protocol.
22. The apparatus for establishing a path according to claim 21, wherein the optical parameters comprise:
maximum ripple, maximum/minimum dispersion of the path, minimum optical return loss of the source reference point, maximum discrete reflection between the source reference point and the destination reference point, maximum dgd, maximum polarization dependent loss, maximum inter-channel crosstalk of the destination reference point, maximum interferometer crosstalk of the destination node, maximum optical path optical signal-to-noise ratio cost.
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| CN103312602B (en) * | 2012-03-15 | 2018-12-28 | 中兴通讯股份有限公司 | A kind of method and system for establishing path |
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