JP6592422B2 - Transmission apparatus and transponder switching method - Google Patents

Description

  The present invention relates to a transmission apparatus used in an optical transmission network and a transponder switching method of the transmission apparatus.

  In recent years, multi-layer optical transmission networks in which a plurality of paths are accommodated hierarchically are becoming widespread. In a multi-layer optical transmission network, when a transponder that becomes the end point of an optical path fails, a transmission device switches the failed transponder to a spare transponder and recovers it. (Non-Patent Document 1).

A conventional transmission apparatus 9 will be described with reference to FIG.
The transmission device 9 is used for the multilayer optical transmission network 90. As shown in FIG. 1, the transmission device 9 includes four intra-office IFs (interfaces) 91, an electrical cross connect (EXC) 92, four transponders (TP) 93, and an optical cross connect ( An OXC (Optical Cross Connect) 94, two inter-station amplifiers (AMP) 95, and a controller 96 are provided.

  The multi-layer optical transmission network 90 hierarchically accommodates paths such as a PW (Pseudo Wire) 90A, an LSP (Label Switched Path) 90B illustrated by a dotted line, and an optical path 90C illustrated by a one-dot chain line. Further, the multi-layer optical transmission network 90 has different path endpoints in the transmission apparatus 9. That is, the end point of the LSP 90B becomes the intra-office IF 91, and the end point of the optical path 90C becomes the transponder 93.

The transmission device 9 is connected to another transmission device (not shown) via the multilayer optical transmission network 90. The transmission device 9 is connected to the communication device 2 in the station via the PW90A.
Hereinafter, the direction from the intra-station communication device 2 to the inter-station optical fiber cable 3 is referred to as “outbound direction”, and the direction from the inter-station optical fiber cable 3 to the intra-station communication device 2 is referred to as “inbound direction (Inbound)”. ) ”.

The transmission device 9 stores and manages various tables necessary for switching. As shown in FIG. 2A, the controller 96 stores a PW mapping table 900, an LSP mapping table 910, and an optical path mapping table 920. Further, as shown in FIG. 2B, the intra-office IF 91 stores the IF destination table 930, the electrical cross-connect 92 stores the EXC destination table 940, the transponder 93 stores the TP destination table 950, and the optical cross-connect. 94 stores the OXC destination table 960. Here, each station within IF91 ₁ ~91 ₄ memorizes the IF destination table ₉₃₀ 1-930 _4, each transponder ₉₃ 1-93 ₄ stores the TP destination table ₉₅₀ 1-950 _4.

  Further, when the packet arrives, the transmission device 9 refers to various tables and determines an output destination. For example, when an outward packet is input from the intra-station IF 91, the electrical cross-connect 92 searches the EXC destination table 940 using the identification information (ID: identification) of the intra-station IF 91 and the LSP label as a search key, and outputs the output destination. The transponder 93 is determined. On the other hand, when an inbound packet is input from the transponder 93, the electrical cross connect 92 searches the EXC destination table 940 using the identification information of the transponder 93 and the LSP label as a search key, and determines the in-station IF 91 of the output destination. .

  In addition, the transmission device 9 switches to another transponder 93 when the transponder 93 fails. Here, in order to switch the transponder 93 that is the end point of the optical path 90C, the transmission apparatus 9 changes the settings of the LSP 90B and the PW 90A accommodated in the optical path 90C in addition to the setting changes of the transponder 93 and the optical path 90C. Is also required.

For example, it is assumed that switching the first transponder 93 ₁ to fourth transponder 93 _4. As shown in FIG. 2 (a), the optical path mapping table 920, the switching from the transponder 93 ₁ to the transponder 93 ₄ is set. Then, the controller 96 refers to the optical path mapping table 920, the electrical cross-connect 92 relative to the transponder 93 and the optical cross-connect 94, an instruction to switch from the transponder 93 ₁ to the transponder 93 _4. In response to this instruction, the electrical cross-connect 92, the EXC destination table 940, rewrites the transponder 93 ₁ identification information ( '1') to the identity of the transponder 93 ₄ ( '4'). Further, the transponder 93 rewrites the TP destination table 950, and the optical cross connect 94 rewrites the OXC destination table 960.

In FIG. 2, the portion rewritten in each table is shown by a thick frame.
Further, in FIG. 2, only one EXC destination table 940 is illustrated for simplicity of explanation, but in reality, the electric cross-connect 92 includes two pieces for the outward direction and the inward direction as described later. Each EXC destination table is stored (see FIG. 3).

Tiejun J. Xia et al., “Introduction of Spectrally and Spatially Flexible Optical Networks,” IEEE Communication Magazine, IEEE, vol. 53, no. 2, pp. 24-33, Feb. 2015.

In the conventional technique, when switching the transponder 93 that is the end point of the optical path 90C, it is necessary to rewrite entries (records) related to all logical paths accommodated by the optical path 90C in the EXC destination table 940. Specifically, the electrical cross-connect 92, as shown in FIG. 3, in the outward direction EXC destination table 940U, rewrite all entries in the identification information of the transponder 93 ₁ to the identification information of the transponder 93 _4. Further, the electrical cross-connect 92, the inner direction EXC destination table 940D, rewrite all entries in the identification information of the transponder 93 ₁ to the identification information of the transponder 93 _4.

  As described above, according to the conventional technique, when the number of logical paths accommodated by the optical path 90C increases, the number of rewrite entries increases. Therefore, there is a high possibility that entry rewrite will fail due to factors such as loss of a control signal. That is, in the conventional technique, when the number of rewrite entries increases, the probability that entry rewrite fails will increase. If entry rewriting fails, the prior art requires retry of entry rewriting, and rapid path switching cannot be realized.

  Therefore, an object of the present invention is to provide a transmission device and a transponder switching method that can reduce the number of rewrite entries.

  In view of the above-described problems, the transmission apparatus according to the present invention is used in an optical transmission network in which a plurality of hierarchical paths including an optical path are set, and serves as an interface of the optical transmission network and an end point of the optical path. A transmission device including a plurality of transponders, a destination table storage unit that stores a destination table in which related information related to the interface is associated with a pointer that is a virtual identifier of the transponder, and the pointer and physical A pointer management table storage unit that stores a pointer management table that associates a physical identifier that is a typical identifier of the transponder, and refers to the destination table and the pointer management table, and sets the destination of data input from the interface. Transponder and input from the transponder A switching function unit for determining the interfaces to be the destination of data, characterized in that it comprises a controller for commanding the switching function unit rewrites the pointer management table.

  Since such a transmission apparatus indirectly designates a physical transponder using a pointer in the destination table, it is only necessary to rewrite the correspondence between the pointer and the physical identifier in the pointer management table when switching the transponder. . As a result, the transmission apparatus can reduce the number of rewrite entries and quickly switch paths.

  In the transmission apparatus according to the present invention, the destination table storage unit stores, as the destination table, a first destination table for determining the transponder and a second destination table for determining the interface, and the pointer management The table storage unit stores, as the pointer management table, a first pointer management table for determining the transponder and a second pointer management table for determining the interface, and the switching function unit includes the first destination table and The first pointer management table is referenced to determine the transponder that is the destination of the data input from the interface, and the second destination table and the second pointer management table are referenced to determine the data input from the transponder. The destination interface It is preferable that the constant.

  Such a transmission apparatus can quickly switch paths by simply rewriting the first pointer management table and the second pointer management table.

  In the transmission apparatus according to the present invention, it is preferable that the destination table storage unit stores an identifier of the interface and a label of the LSP as related information of the interface.

  Such a transmission apparatus can quickly switch paths in an optical transmission network that hierarchically accommodates PWs, LSPs, and optical paths.

  Further, in view of the above problems, the transponder switching method according to the present invention is a transponder switching method for switching the transponder of the transmission apparatus according to the present invention, and the physical identifier of the transponder before and after switching is input to the controller. An input step that instructs the switching function unit to rewrite the pointer management table based on the physical identifier of the transponder input in the input step; and the switching function unit includes the controller And a rewriting step of rewriting the pointer management table stored in the pointer management table storage unit in response to a command from the device.

  In such a transponder switching method, a physical transponder is indirectly specified using a pointer in the destination table. Therefore, when the transponder is switched, it is only necessary to rewrite the correspondence between the pointer and the physical identifier in the pointer management table. Good. Thereby, in the transponder switching method, the number of rewrite entries can be reduced and the path can be switched quickly.

  In the transponder switching method according to the present invention, the pointer management table storage unit stores, as the pointer management table, a first pointer management table for determining the transponder and a second pointer management table for determining the interface. In the rewriting step, the switching function unit rewrites the physical identifier of the transponder before switching in the first pointer management table with the physical identifier of the transponder after switching, and the second pointer management table rewrites the physical identifier of the transponder. In the record corresponding to the physical identifier of the transponder before switching, the pointer of the record is rewritten as not applicable, and in the record corresponding to the physical identifier of the transponder after switching in the second pointer management table. A pointer record, it is preferable to rewrite the pointer representing the physical identifier of the switching front of the transponder.

  In such a transponder switching method, paths can be switched quickly only by rewriting the first pointer management table and the second pointer management table.

  In the transponder switching method according to the present invention, the switching function unit refers to the destination table and the pointer management table after rewriting in the rewriting step, and serves as a destination of data input from the interface. And a switching step of determining an interface as a destination of data input from the transponder.

  In such a transponder switching method, it is possible to quickly switch paths by referring to the rewritten pointer management table.

  According to the present invention, the number of rewrite entries can be reduced and rapid path switching can be realized.

It is a block diagram which shows the structure of the conventional transmission apparatus. (A) is a figure which shows the data structure of a mapping table, (b) is a figure which shows the data structure of a destination table. It is explanatory drawing explaining rewriting of the table accompanying switching of a transponder. It is a schematic block diagram of the transmission system in this invention. It is explanatory drawing explaining the hierarchy of a multilayer optical transmission network. It is a block diagram which shows the structure of the transmission apparatus which concerns on this invention. (A) is a figure which shows the data structure of an outer direction EXC destination table, (b) is a figure which shows the data structure of an inner direction EXC destination table. (A) is a figure which shows the data structure of an outward direction pointer management table, (b) is a figure which shows the data structure of an inward direction pointer management table. It is a flowchart which shows operation | movement of the transmission apparatus of FIG. It is explanatory drawing explaining rewriting of the pointer management table by a transmission apparatus.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate. In addition, the same code | symbol was attached | subjected to the same means and description was abbreviate | omitted.

[Outline of transmission system]
The outline of the transmission system 1 in the present invention will be described with reference to FIG.
As shown in FIG. 4, the transmission system 1 transmits data (packets) between two communication devices 2 (2 ₁ , 2 ₂ ) via a multilayer optical transmission network 90 (90 ₁ , 90 ₂ ). It transmits and receives, and includes three transmission apparatuses 10 (10 ₁ to 10 ₃ ) and an optical fiber cable 3.

The transmission system 1, via a multi-layer optical transmission network 90 ₁ connects the transmission device ₁₀ 1, 10 _2. For example, the upper loop contained Multilayer optical transmission network 90 ₁ is a relay network between regions.
The transmission system 1, via a multi-layer optical transmission network 90 ₂ connects the transmission device ₁₀ 2, 10 _3. For example, the lower loop contained Multilayer optical transmission network 90 ₂ is a concentrator network in the region.
Therefore, the transmission device 10 ₂ serves as a multi-layer optical transmission network ₉₀ 1, 90 ₂ of the relay devices.

The transmission system 1 connects the transmission _device 101 and the communication apparatus _{2 1} connects the transmission device ₁₀₃ and the communication apparatus _{2 2.} The communication devices 2 ₁ and 2 ₂ are communication devices such as routers, for example, and are not managed by the transmission system 1.

  As shown in FIG. 5, the multilayer optical transmission network 90 hierarchically accommodates paths such as PW 90A, LSP 90B, and optical path 90C. That is, one optical path 90C accommodates one or more LSPs 90B, and one LSP 90B accommodates one or more PWs 90A.

  In the transmission system 1, the number of communication devices 2 and the transmission devices 10 and the network configuration are not limited to the example in FIG. For example, the transmission system 1 can be applied to an optical transmission network having only a relay network or an optical transmission network having only a concentrating network.

[Configuration of transmission equipment]
The configuration of the transmission device 10 will be described with reference to FIG.
As shown in FIG. 6, the transmission apparatus 10 includes an interface unit (intra-office IF 11, transponder 13, inter-station amplifier 15), a switching function unit (electric cross connect 12, optical cross connect 14), and a control function unit (controller 16 ).

In the present embodiment, the transmission device 10 includes four station IF 11 ₁ to 11 _4, and one electrical cross-connect 12, and four transponders _131-134, and one optical cross-connect 14, Two inter-station amplifiers 15 ₁ and 15 ₂ and one controller 16 are provided.
Note that the transmission apparatus 10 may include two electrical cross-connects 12, two optical cross-connects 14, and two controllers 16 for redundancy (not shown).

The in-station IF 11 is an interface with the communication apparatus 2 and is the same as the in-station IF 91 in FIG.
Specifically, the intra-station IF 11 stores the IF destination table 930 in FIG. Then, when the outward data is input from the communication device 2, the intra-station IF 11 searches the IF destination table 930 using the identification information of the PW 90A added to the data as a search key, and acquires the LSP label. Further, the in-station IF 11 outputs the identification information assigned to the in-station IF 11 and the acquired LSP label to the electrical cross connect 12.

<Data structure of IF destination table>
The data structure of the IF destination table 930 will be described with reference to FIG.
The IF destination table 930 includes data items “PW ID” and “LSP label” as shown in FIG. In this IF destination table 930, 'PW ID' is a search key.

'PW ID' represents identification information for uniquely identifying PW90A such as 'a11' and 'a12'.
'LSP label' represents the label name of LSP90B, such as '1001'.

  The intra-station IF 11 may store a special memory configured with hardware for the IF destination table 930. At this time, since the in-station IF 11 cannot arbitrarily set a search key, it stores two IF destination tables for the outward direction and the inward direction. Specifically, the intra-station IF 11 uses the IF destination table 930 in FIG. 2B for the outward direction, and uses a table in which data items are arranged opposite to the IF destination table 930 for the inward direction (not shown).

  Therefore, when the inward data is input from the electrical cross connect 12, the in-station IF 11 searches the inbound IF destination table using the LSP label as a search key, and acquires the identification information of the PW 90A.

Returning to FIG. 6, the description of the transmission apparatus 10 will be continued.
The electrical cross-connect 12 refers to the destination table and the pointer management table, and determines the transponder 13 that is the destination of the data input from the in-station IF 11 and the in-station IF 11 that is the destination of the data input from the transponder 13. is there.

In the present embodiment, the electrical cross connect 12 includes a destination table storage unit 121 and a pointer management table storage unit 123.
The destination table storage unit 121 stores an outer direction EXC destination table (first destination table) for determining the transponder 13 and an inner direction EXC destination table (second destination table) for determining the in-station IF 11 as destination tables.
The pointer management table storage unit 123 includes, as pointer management tables, an outward pointer management table (first pointer management table) for determining the transponder 13 and an inward pointer management table (second pointer management table) for determining the in-station IF 11. Remember.

<Data Structure of Outward EXC Destination Table and Inward Direction EXC Destination Table>
With reference to FIG. 7, the data structure of the outward EXC destination table 200U and the inward EXC destination table 200D will be described.

  As shown in FIG. 7A, the outward EXC destination table 200U has data items of 'IF ID', 'LSP label', and 'TP ID'. In this outward EXC destination table 200U, 'IF ID' and 'LSP label' are search keys.

'IF ID' represents identification information for uniquely identifying the in-station IF 11. For example, the identification information of the _first in-station IF 11 ₁ is “1”, the identification information of the second in-station IF 112 ₂ is “2”, and the identification information of the third in-station IF 11 ₃ is “3”.
“TP ID” represents a pointer of the transponder 13. The pointer is an identifier that uniquely identifies the virtual transponder 13. In this embodiment, “*” represents a pointer. For example, the pointer of the _first transponder 131 is “* 1”, and the pointer of the _second transponder 132 is “* 2”.

  In the inward EXC destination table 200D, as shown in FIG. 7B, the same data items as in the outward EXC destination table 200U are arranged in reverse. In this inward EXC destination table 200D, “TP ID” and “LSP label” are search keys.

<Data Structure of Outward Pointer Management Table and Inward Pointer Management Table>
With reference to FIG. 8, the data structures of the outward pointer management table 210U and the inward pointer management table 210D will be described.

  As shown in FIG. 8A, the outward pointer management table 210U has data items 'vTP ID' and 'TP ID'. In this outward direction pointer management table 210U, 'vTP ID' is a search key.

'vTP ID' represents the pointer of the transponder 13.
“TP ID” represents a physical identifier of the transponder 13. This physical identifier is an identifier that uniquely identifies the physical transponder 13. For example, the physical identifier of the _first transponder 131 is “1”, the physical identifier of the _second transponder 132 is “2”, and the physical identifier of the _third transponder 133 is “3”.
In this outward pointer management table 210U, there is no entry corresponding to the pointer of the _fourth transponder 134.

In the inward pointer management table 210D, as shown in FIG. 8B, the same data items as the outward pointer management table 210U are arranged in reverse. In this inward pointer management table 210D, “TP ID” is a search key.
In this inward pointer management table 210D, an entry corresponding to the pointer of the _fourth transponder 134 is set to “null”. This “null” indicates that the pointer of the transponder 13 is “not applicable”.

  Note that a method of switching the transponder 13 by the electric cross-connect 12 will be described in detail in the operation of the transmission apparatus 10 described later.

Returning to FIG. 6, the description of the transmission apparatus 10 will be continued.
The transponder 13 is an end point of the optical path 90C and is the same as the transponder 13 in FIG.
Specifically, the transponder 13 stores the TP destination table 950 in FIG. Then, when the outward data is input from the electrical cross connect 12, the transponder 13 searches the TP destination table 950 and acquires the wavelength band information. Further, the transponder 13 outputs the pointer assigned to the transponder 13 and the acquired wavelength band information to the optical cross connect 14.
Further, when inward data is input from the optical cross connect 14, the transponder 13 outputs the pointer assigned to the transponder 13 and the LSP label added to the data to the electrical cross connect 12.

<Data structure of TP destination table>
The data structure of the TP destination table 950 will be described with reference to FIG.
As shown in FIG. 2B, the TP destination table 950 has a data item “λ”.
'λ' represents wavelength band information such as '23'. This wavelength band information is identification information for uniquely identifying a wavelength band divided for each predetermined range.
Since only one wavelength band is allocated to one transponder 13, there is only one entry in the TP destination table 950. Therefore, there is no search key for the TP destination table 950.

Returning to FIG. 6, the description of the transmission apparatus 10 will be continued.
The optical cross-connect 14 is a cross-connect device for optical signals, and is similar to the optical cross-connect 94 in FIG.
Specifically, the optical cross connect 14 stores the OXC destination table 960 in FIG. Then, when the outward data from the transponder 13 is input, the optical cross connect 14 searches the OXC destination table 960 using the pointer and wavelength band information of the transponder 13 added to the data as a search key, The identification information of the amplifier 15 is acquired. Further, the optical cross connect 14 outputs data to the inter-station amplifier 15 corresponding to the acquired identification information.

<Data structure of OXC destination table>
The data structure of the OXC destination table 960 will be described with reference to FIG.
As shown in FIG. 2B, the OXC destination table 960 includes data items “TP ID”, “λ”, and “AMP ID”. In the OXC destination table 960, TP ID 'and' λ 'are search keys.

'AMP ID' represents identification information for uniquely identifying the inter-station amplifier 15. For example, “AMP ID” of the _first inter-station amplifier 151 is “1”, and “AMP ID” of the _second inter-station amplifier 152 is “2”.
“TP ID” represents a physical identifier of the transponder 13.

  Note that the optical cross connect 14 may store two IF destination tables for the outward direction and the inward direction, similarly to the intra-office IF 11. In this case, the in-station IF 11 uses the OXC destination table 960 in FIG. 2B for the outward direction, and uses a table in which data items are arranged in reverse to the OXC destination table 960 for the inward direction (not shown).

  Therefore, when inward data is input from the interoffice amplifier 15, the optical cross connect 14 searches the OXC destination table for inward using the identification information of the interoffice amplifier 15 as a search key, and the physical of the transponder 13. An identifier and wavelength band information are acquired.

  The inter-station amplifier 15 is an amplifier that amplifies an optical signal transmitted through the optical path 90C. The inter-station amplifier 15 is the same as the inter-station amplifier 15 in FIG.

  The controller 16 controls the interface unit and the switching function unit. Further, the controller 16 stores the PW mapping table 900, the LSP mapping table 910, and the optical path mapping table 920 shown in FIG.

<Data structure of mapping table>
The data structures of the PW mapping table 900, the LSP mapping table 910, and the optical path mapping table 920 will be described with reference to FIG.

As shown in FIG. 2A, the PW mapping table 900 has data items 'PW ID', 'IF ID', and 'LSP ID'.
'LSP ID' represents identification information for uniquely identifying LSP 90B, such as 'a1' and 'a2'.

The LSP mapping table 910 has data items of “LSP ID”, “IF ID”, “LSP label”, and “OP ID”.
'OP ID' represents identification information for uniquely identifying the optical path 90C, such as 'a'.

The optical path mapping table 920 has data items of “OP ID”, “TP ID”, “λ”, and “AMP ID”.
Based on the PW mapping table 900, the LSP mapping table 910, and the optical path mapping table 920, an IF destination table 930, a TP destination table 950, and an OXC destination table 960 are generated.

  Here, the controller 16 receives rewrite information from the outside (for example, an administrator of the transmission apparatus 10). This rewrite information represents the physical identifier of the transponder 13 before and after switching. Then, the controller 16 rewrites the LSP mapping table 910 and the optical path mapping table 920 based on the input rewrite information. Further, the controller 16 instructs the electrical cross connect 12 to rewrite the outer pointer management table 210U and the inner pointer management table 210D.

[Transmission Device Operation: Transponder Switching Method]
A transponder switching method by the transmission apparatus 10 will be described with reference to FIGS. 9 and 10 (see FIG. 6 as appropriate).
Here, a description will be given assuming that the _first transponder 13 ₁ is switched to the _fourth transponder 13 ₄ .

As shown in FIG. 9, the controller 16 receives input of rewrite information from the outside (step S1: input step).
For example, the controller 16, as renewal information, a physical identifier of the transponder 13 ₁ before switching '1', and a physical identifier of the transponder 13 ₄ after switching '4' is entered.

The controller 16 commands the electrical cross-connect 12 to rewrite the outer pointer management table 210U and the inner pointer management table 210D based on the rewriting information input in step S1 (step S2: command step).
For example, the controller 16, to the electrical cross-connect 12, an instruction to rewrite from the transponder 13 ₁ to the transponder 13 _4.

The electrical cross connect 12 rewrites the outer pointer management table 210U and the inner pointer management table 210D in accordance with a command from the controller 16 (step S3: rewrite step).
Since the rewriting step is composed of steps S30 to S32, it will be described in order.

As shown in FIG. 10, the electrical cross-connect 12, the outer direction pointer management table 210U, before switching of the transponder 13 _first physical identifier is rewritten to the physical identifier of the transponder 13 ₄ after the switching (step S30).
That is, the electrical cross-connect 12 rewrites the physical identifier (TP ID) of the entry corresponding to the pointer (vTP ID) “* 1” from “1” to “4” in the outward pointer management table 210U.

The electrical cross-connect 12, the record corresponding to before switching of the transponder 13 ₁ physical identifiers inward pointer management table 210D, rewrites a pointer to this record 'null' (step S31).
That is, the electrical cross connect 12 rewrites the pointer (vTP ID) of the entry corresponding to the physical identifier (TP ID) of the transponder 13 from “* 1” to “null” in the inward pointer management table 210D. .

The electrical cross-connect 12, the record corresponding to the physical identifier of the inward pointer management transponder 13 ₄ after the switching table 210D, a pointer to this record is rewritten to the transponder 13 ₁ pointer before switching (step S32) .
That is, the electrical cross connect 12 rewrites the pointer (vTP ID) of the entry corresponding to the physical identifier (TP ID) of the transponder 13 from “4” to “* 1” in the inward pointer management table 210D. .

As described above, the electrical cross-connect 12 can switch the transponder 13 without rewriting other tables only by rewriting three locations (three entries) in the outer pointer management table 210U and the inner pointer management table 210D. Can do.
Steps S30 to S32 are not particularly limited in order of processing, and may be executed in any order.

  The electrical cross-connect 12 performs switching by referring to the outer pointer management table 210U and the inner pointer management table 210D and the outer pointer management table 210U and the inner pointer management table 210D after being rewritten in step S3 (step S3). S4).

  Specifically, when the outward data is input from the intra-station IF 11, the electrical cross connect 12 searches the outer pointer management table 210 U using the identification information of the intra-station IF 11 and the LSP label as a search key, and the transponder 13. Get the pointer. The electrical cross connect 12 searches the outward pointer management table 210U using the acquired pointer as a search key, and acquires the physical identifier of the transponder 13. In this way, the electrical cross connect 12 can determine the output transponder 13.

Further, when inward data is input from the transponder 13, the electrical cross connect 12 searches the inward pointer management table 210D using the physical identifier of the transponder 13 as a search key, and acquires the pointer of the transponder 13. . Then, the electrical cross connect 12 searches the inward EXC destination table 200D using the pointer of the transponder 13 and the LSP label as search keys, and acquires the identification information of the in-station IF 11 In this way, the electrical cross connect 12 can determine the in-station IF 11 as the output destination.
Since the process of step S4 is the same as that of the transmission apparatus 9 of FIG.

[Action / Effect]
The transmission apparatus 10 can significantly reduce the number of rewrite entries when switching the transponder 13 that is the end point of the optical path, as compared with the conventional technique. That is, in the conventional technique, the number of rewrite entries increases in proportion to the number of logical paths accommodated by the optical path. On the other hand, in the transmission apparatus 10, the number of rewrite entries is constant (for example, 3 entries). As described above, the transmission apparatus 10 can reduce the number of rewrite entries, thereby suppressing the frequency of entry rewrite failures and realizing rapid path switching.

As mentioned above, although each embodiment of this invention was explained in full detail, this invention is not limited to above-mentioned each embodiment, The design change etc. of the range which does not deviate from the summary of this invention are included.
In the embodiment described above, two EXC destination tables and pointer management tables are provided for the outward direction and the inward direction, respectively, but the present invention is not limited to this. That is, the transmission apparatus may include only one EXC destination table and one pointer management table.

10 transmission devices 11 and 11 _{1 to} 11 ₄ intra-station IF (interface)
12 Electric cross-connect (switching function part)
13, 13 _{1-13 4} transponder 14 optical cross-connect 15, 15 _1, 15 ₂ between stations amplifier 16 Controller

Claims (6)

A transmission apparatus used in an optical transmission network in which a plurality of hierarchical paths including an optical path are set, and including a plurality of interfaces of the optical transmission network and transponders serving as end points of the optical path;
A destination table storage unit that stores a destination table in which related information related to the interface is associated with a pointer that is a virtual identifier of the transponder;
A pointer management table storage unit that stores a pointer management table in which the pointer is associated with a physical identifier that is a physical identifier of the transponder;
A switching function unit that refers to the destination table and the pointer management table, determines a transponder that is a destination of data input from the interface, and an interface that is a destination of data input from the transponder;
And a controller that commands the switching function unit to rewrite the pointer management table. The destination table storage unit stores, as the destination table, a first destination table for determining the transponder and a second destination table for determining the interface,
The pointer management table storage unit stores, as the pointer management table, a first pointer management table for determining the transponder and a second pointer management table for determining the interface,
The switching function unit refers to the first destination table and the first pointer management table, determines a transponder as a destination of data input from the interface, and determines the second destination table and the second pointer management table. The transmission apparatus according to claim 1, wherein an interface serving as a destination of data input from the transponder is determined with reference to FIG.   The transmission apparatus according to claim 1, wherein the destination table storage unit stores an identifier of the interface and an LSP label as related information of the interface. A transponder switching method for switching the transponder of the transmission device according to claim 1,
An input step in which a physical identifier of the transponder before and after switching is input to the controller;
Based on the physical identifier of the transponder input in the input step, the controller instructs the switching function unit to rewrite the pointer management table;
The switching function unit rewrites the pointer management table stored in the pointer management table storage unit in response to a command from the controller;
A transponder switching method comprising: The pointer management table storage unit stores, as the pointer management table, a first pointer management table for determining the transponder and a second pointer management table for determining the interface;
In the rewriting step, the switching function unit is
In the first pointer management table, the physical identifier of the transponder before switching is rewritten to the physical identifier of the transponder after switching,
In the record corresponding to the physical identifier of the transponder before switching in the second pointer management table, the pointer of the record is rewritten as not applicable,
5. The transponder switching method according to claim 4, wherein, in the record corresponding to the physical identifier of the transponder after switching in the second pointer management table, the pointer of the record is rewritten to the pointer of the transponder before switching. . The switching function unit refers to the destination table and the pointer management table after rewriting in the rewriting step, the transponder that is the destination of the data input from the interface, and the data input from the transponder A switching step to determine the destination interface,
The transponder switching method according to claim 4 or 5, further comprising:

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