JP6083285B2 - Transmission signal processing device - Google Patents

Description

  The present invention relates to a transmission signal processing apparatus capable of switching TDM (Time Division Multiplexing) signals and packets.

  Patent Document 1 describes a device that can efficiently switch a TDM signal for a synchronous network and a packet for an asynchronous network within the same device. However, the device described in Patent Document 1 is intended for mere switching, and cannot perform format conversion between a TDM signal and a packet. For this reason, in order to send the TDM signal to the asynchronous network, another apparatus for performing format conversion must be prepared.

  Patent Document 2 describes an apparatus that can convert a TDM signal into a packet. The device described in Patent Document 2 includes a TDM interface unit, a packet / depacketization unit, and a packet interface unit. A time switch is provided between the TDM interface unit and the packet / depacketization unit, and the packet / depacketization unit and the packet interface. Switching between each part is performed by a packet switch.

JP 2003-289324 A JP 2011-044973 A

  However, Patent Document 2 describes only switching between a TDM port and a packet port, and does not mention how to switch between TDM ports or between packet ports. Further, the technology described in Patent Document 2 uses two switches, a time switch and a packet switch, and the overall configuration is large and complicated.

  Therefore, there is a demand for a transmission signal processing apparatus having a small size and a simple configuration that can cope with various types of switching.

The transmission signal processing apparatus of the present invention includes (1) a packet switch for switching a packet of a predetermined format, (2) a TDM input interface unit for processing an incoming TDM signal, and (3) a packet from the packet switch. A TDM output interface unit that performs output processing of a TDM signal obtained by depacketization; (4) a packet input interface unit that performs input processing on an incoming packet and applies the packet to the packet switch; and (5) provided from the packet switch. (6) the TDM input interface unit converts the incoming TDM signal into the packet of the predetermined format, and the destination interface unit from the packet switch is the TDM output interface. Part Expediently, it applied to the packet switch and a packet into packet grant line specific information within the TDM output interface unit, if the destination interface unit from the packet switch is the packet output interface unit, the packet It packetizes the granted line specific information in the output interface unit packet and having a packetizing means Ru applied to the packet switch.

  ADVANTAGE OF THE INVENTION According to this invention, the transmission signal processing apparatus of a small and simple structure which can respond to various switching can be provided.

It is a block diagram which shows the structure of the transmission signal processing apparatus of embodiment. It is explanatory drawing which shows the format of the packet in the apparatus in the transmission signal processing apparatus of embodiment. It is explanatory drawing which shows the structure of the table for reception in the TDM interface board of the transmission signal processing apparatus of embodiment. It is explanatory drawing which shows the structure of the table for reception in the packet interface board of the transmission signal processing apparatus of embodiment. It is explanatory drawing which shows the structure of the table for transmission in the TDM interface board of the transmission signal processing apparatus of embodiment. It is explanatory drawing which shows the structure of the table for transmission in the packet interface board of the transmission signal processing apparatus of embodiment.

(A) Main Embodiment Hereinafter, an embodiment of a transmission signal processing apparatus according to the present invention will be described in detail with reference to the drawings.

(A-1) Configuration of Embodiment FIG. 1 is a block diagram illustrating a configuration of a transmission signal processing device 1 of the embodiment.

  In FIG. 1, the transmission signal processing apparatus 1 according to the embodiment includes one or more TDM interface boards 100 (100-1, 100-2) and one or more packet interface boards 200 (200-1, 200-2). And a packet switch 300.

  The TDM interface board 100 accommodates a TDM port for inputting / outputting a TDM signal, and includes a TDM reception processing unit 101 and a TDM transmission processing unit 102. In FIG. 1, the TDM reception processing unit 101 is described for the TDM interface board 100-1, and the TDM transmission processing unit 102 is described for the TDM interface board 100-2. However, this is because FIG. 1 is drawn with emphasis on the signal flow, and both the TDM interface boards 100-1 and 100-2 have the TDM reception processing unit 101 and the TDM transmission processing unit 102. Note that the TDM interface boards 100-1 and 100-2 in FIG. 1 may be the same board.

  The TDM reception processing unit 101 performs reception processing of the incoming TDM signal 400, and performs packetization processing of the TDM signal 401 received by the TDM reception unit 110 to perform intra-device packet 500 (FIG. 2), and a reception table that extracts header information 403 to be inserted into the header of the packet based on the header search information 402 given from the packetizing unit 120 and returns it to the packetizing unit 120 130 (see FIG. 3 described later).

  Here, the header search information 402 is, for example, the port number, path number, and channel number of the TDM signal to be packetized. The header information 403 is, for example, a destination local address, a Type value of an Ethernet (registered trademark) header, and a Label value of an MPLS-TP (Multi Protocol Label Switching-Transport Profile) header. The local address is an address closed in the device assigned to the switch interface of each interface board 100-1, 100-2, 200-1, 200-2 in order to perform switching in the device 10.

  The TDM transmission processing unit 102 includes a depacketizing unit 140 that converts the in-device packet 502 received from the packet switch 300 into a TDM signal 410 and a TDM depacketized based on the header search information 412 provided from the depacketizing unit 140. The transmission table 150 (see FIG. 5 to be described later) that extracts the channel information 413 included in the signal and sends it back to the depacketization unit 140, and the transmission process of the depacketized TDM signal 410 are performed to output the TDM signal 411 from the output port. A TDM transmitter 160 for transmission.

  Here, the header search information 412 is, for example, the source local address, the Ethernet header Type value, and the MPLS-TP header Label value, and the TDM signal channel information 413 includes, for example, the port number and path associated with the TDM signal. Number and channel number.

  The packet interface board 200 accommodates a packet port for inputting and outputting packets, and includes a packet reception processing unit 201 and a packet transmission processing unit 202. In FIG. 1, a packet reception processing unit 201 is described for the packet interface board 200-1, and a packet transmission processing unit 202 is described for the packet interface board 200-2. However, this is because FIG. 1 is drawn with emphasis on the signal flow, and both the packet interface boards 200-1 and 200-2 have a packet reception processing unit 201 and a packet transmission processing unit 202. Note that the packet interface boards 200-1 and 200-2 in FIG. 1 may be the same board.

  The packet reception processing unit 201 is provided from the packet reception unit 210 that performs reception processing of the incoming packet 420, the header replacement unit 220 that generates the in-device packet 501 by replacing the header of the received packet 421, and the header replacement unit 220. A receiving table 230 (see FIG. 4 to be described later) that extracts header information 423 included in the in-device packet 501 after replacement based on the header search information 422 and returns it to the header replacement unit 220.

  Here, the header search information 422 is, for example, the source MAC address of the packet and the Label value of the MPLS-TP header, and the header information 423 is, for example, the destination local address and the Label value of the MPLS-TP header.

  The packet transmission processing unit 202 extracts the header information 433 based on the header replacement unit 240 that replaces the Ethernet header of the packet 503 received from the packet switch 300, and the header search information 432 provided from the header replacement unit 240. A transmission table 250 (see FIG. 6 to be described later) that sends a reply to the replacement unit 240, and a packet transmission unit 260 that performs transmission processing of the packet 430 generated by the header replacement unit 240 and transmits the packet 431 from the output port. .

  Here, the header search information 432 is, for example, the transmission source local address of the in-device packet 503 and the Label value of the MPLS-TP header, and the header information 433 is, for example, the MAC address and the Label value of the MPLS-TP header. .

  The packet switch 300 performs switching of the in-device packet 500 output from the TDM interface board 100 and the in-device packet 501 output from the packet interface board 200, and uses the Ethernet header or MPLS-TP header of the in-device packets 501 and 502. This is given to the TDM interface board 100 or the packet interface board 200 to be determined. For example, the in-device packet 500 output from the TDM interface board 100-1 may be given to the TDM interface board 100-2 or may be given to the packet interface board 200-2. For example, the in-device packet 501 output from the packet interface board 200-1 may be provided to the TDM interface board 100-2 or may be provided to the packet interface board 200-2.

  FIG. 2 is an explanatory diagram showing the format of the in-device packets (500 to 503) switched by the packet switch 300. As is apparent from FIG. 2, the in-device packet conforms to a packet format conforming to the MPLS-TP packet transfer method (hereinafter referred to as an MPLS packet). In this embodiment, packets input to the packet interface board 200-1 and packets output from the packet interface board 200-2 also follow the format shown in FIG.

  The in-device packet is composed of an Ethernet header, an MPLS-TP header, a payload, and FCS (Frame Check Sequence). The Ethernet header has fields of a destination MAC address (DA), a source MAC address (SA), and a Type value, and an MPLS-TP header has a Label value, a time code (TC), an S value, and a TTL (Time TO Live). ) Has a value filter. In the case of an in-device packet directed to the TDM interface board 100-2, a dummy label value is inserted into the Label value, and a value indicating that the dummy label value is inserted into the Type value. On the other hand, in the case of an in-device packet directed to the packet interface board 200-2, a general MPLS-TP label value is inserted into the Label value, and a valid value of the MPLS-TP label is inserted into the Type value. A value indicating that is inserted. In the case of an in-device packet output from the TDM interface board 100-1, data obtained by packetizing a TDM signal (encapsulated packet) is inserted into the payload, and in the case of an in-device packet output from the packet interface board 200-1. In the payload, the data inputted to the board is inserted as it is.

  FIG. 3 is an explanatory diagram showing the configuration of the reception table 130 in the TDM interface board (100-1).

  In the reception table 130, input information is the port number, path number, and channel number of the TDM signal, and output information is the destination local address, the Ethernet header Type value, and the MPLS-TP header Label value. In the case of this embodiment, the Type value of the Ethernet header is information that can distinguish whether the destination of the in-device packet by the packet switch 300 is the TDM interface board 100 or the packet interface board 200. When the destination is the packet interface board 200, for example, as shown in the first line, “0x8847” that is generally used in the case of an MPLS packet is stored in the Type value field of the Ethernet header, and the destination is the TDM interface. In the case of the board 100, for example, as shown in the second row, a meaningless fixed value “0xFFFF” is stored. “DL1” in FIG. 3 represents one of the dummy label values, and when the destination is any TDM interface board 100, the dummy label value DL1 is associated.

  FIG. 4 is an explanatory diagram showing the configuration of the reception table 230 in the packet interface board (200-1).

  In the reception table 230, the input information is the source MAC address and the Label value of the MPLS-TP header, and the output information is the destination local address and the Label value of the MPLS-TP header. The first line of FIG. 4 shows the case where the output of the packet switch 300 is given to the packet interface board (200-2), and the second line of FIG. 4 shows the output of the packet switch 300 as the TDM interface board (100-2). The conversion is basically the same, but the conversion of the Label value is also performed in the former case, but the conversion of the Label value is not executed in the latter case. . This is because when the destination of the packet switch 300 is a TDM interface board, it is necessary to convert the label value from the label value to the port number, the pass number, and the channel number in the TDM interface board. No conversion is performed and the Label value is transmitted. However, the Label value may be changed as long as it is a unique value managed in the apparatus. When the destination is a packet interface board, the Label value is converted because the source is converted when the Label value is different between the source and the destination.

  FIG. 5 is an explanatory diagram showing the configuration of the transmission table 150 in the TDM interface board (100-2).

  In the transmission table 150, the input information is the destination local address, the Ethernet header Type value, and the MPLS-TP header Label value, and the output information is the TDM signal port number, path number, and channel number. In the first line, since the Type value of the Ethernet header is “0x8847” and a valid value (not a dummy label value) is inserted in the Label value of the MPLS-TP header, the transmission source board is the packet interface board. This is the case of (200-1). The second line is when the type value of the Ethernet header is “0xFFFF” and the dummy label value is inserted in the Label value of the MPLS-TP header, so that the transmission source board is the TDM interface board (100-1). is there.

  FIG. 6 is an explanatory diagram showing the configuration of the transmission table 250 in the packet interface board 200.

  In the transmission table 250, input information includes a source local address, a type value of an Ethernet header, and a Label value of an MPLS-TP header, and output information includes header information including a port number, a destination MAC address, and a source MAC address. 433.

  Next, the dummy label will be supplementarily described.

  The dummy label is a value of a label closed in the apparatus, which is given to the Label value field of the MPLS-TP header in order to identify the line in the destination interface board of the packet switch 300. When the TDM interface board accommodates a plurality of channels, a channel number is assigned to the dummy label in order to specify the channel number. In addition, when a plurality of paths and a plurality of ports are accommodated, a path number and a port number are also given.

<Granting example 1>
In the following, a description will be given of an example in which the destination interface board of the packet switch 300 has a configuration in which the number of ports is 1, the number of paths is 1, and the number of channels is 24.

  The dummy label is “DDDD_DDDD_DDDD_DDDC_CCCC” (separation every 4 bits is for easy reading, and there is no meaning for the separation; the same applies to the example 2). The upper 15 bits are unused bits (fixed to 0) D, and the lower 5 bits “CCCCC” are channel number specifying bits and take values in the range of 00000 to 10111. For example, “channel number-1” is assigned to the channel number specifying bit.

<Granting example 2>
In the following, a description will be given of an example in which the destination interface board of the packet switch 300 has a configuration with 8 ports, 84 paths, and 96 channels.

  The dummy label is “DDDA_AAPP_PPPP_PCCC_CCCC”. The upper 3 bits are unused bits (fixed to 0) D. The next three bits “AAA” are port number specifying bits and take values in the range of 000 to 111. For example, “port number-1” is assigned to the port number specifying bit. Further, the next 7 bits “PPPPPPP” are pass number specifying bits and take values within the range of 0000000 to 1010011). For example, “pass number −1” is assigned to the pass number specifying bit. The lower 7 bits “CCCCCCCC” are channel number specifying bits and take values in the range of 0000000 to 1011111. For example, “channel number-1” is assigned to the channel number specifying bit.

(A-2) Operation of Embodiment Next, the operation of the transmission signal processing device 1 of the embodiment is the operation of the TDM reception processing unit 101 of the TDM interface board 100, the operation of the packet reception processing unit 201 of the packet interface board 200, The operation of the packet switch 300, the operation of the TDM transmission processing unit 102 of the TDM interface board 100, and the operation of the packet transmission unit 202 of the packet interface board 200 will be described in this order.

  First, the operation of the TDM reception processing unit 101 of the TDM interface board (100-1) will be described.

  The TDM receiving unit 110 receives the TDM signal 400 and performs reception processing on the TDM signal 401 (main signal data) to the packetizing unit 120. The packetizing unit 120 encapsulates the TDM signal 401 by CESoPSN (RFC5086; Structure-aware TDM Circuit Emulation Service over Packet Switched Network) and the like, and also searches the input port number, channel number, and channel number of the TDM signal 401. As information 402, header information 403 including a destination local address, a type value of the Ethernet header, and a label value of the MPLS-TP label is retrieved from the reception table 130. Here, the destination local address is information for switching to the destination board of the packet switch 300, the Type value of the Ethernet header and the Label value of the MPLS-TP header are information for specifying the line by the destination board of the packet switch 300 Used as When the destination of the packet switch 300 is the packet interface board (200-2), the Label value of the MPLS-TP header stores the Label value in the transmission packet 431 from the packet interface board (200-2). In the case of the TDM interface board (100-2), a dummy label for specifying a line in the transmission TDM signal 411 from the TDM interface board (100-2) is stored. The Type value of the Ethernet header stores “0x8847” that is generally used for MPLS packets when the destination board of the packet switch 300 is the packet interface board (200-2). In the case of the TDM interface board (100-2), “0xFFFF” is stored. This makes it possible to distinguish between a Label value and a dummy label value. The packetization unit 120 performs packetization based on the information from the reception table 130, generates an in-device packet 500, and gives it to the packet switch 300.

  Next, the operation of the packet reception processing unit 201 of the packet interface board (200-1) will be described.

  The packet receiving unit 210 performs reception processing on the incoming packet 420 and gives the packet 421 after reception processing to the header reassigning unit 220. The header re-assignment unit 220 uses the packet source MAC address and the MPLS value of the MPLS-TP header as header search information 422, and receives header information 423 including the destination local address and the label value of the MPLS-TP header from the reception table 230. Search for. When the destination board of the packet switch 300 is the packet interface board (200-2), the Label value of the MPLS-TP header stored in the reception table 230 is a transmission packet from the packet interface board (200-2). When the destination board is the TDM interface board (100-2), it is the Label value of the received packet 420. The header replacement unit 220 performs header replacement based on the information from the reception table 230, generates an in-device packet 501, and gives the packet switch 300.

  Next, the operation of the packet switch 300 will be described.

  The packet switch 300 performs switching with reference to the destination local address of the packet 500 or 501 received from the interface board (100-1, 200-1), and outputs the output packet 502 or 503 to the interface board (100-2, 200-). Send to 2).

  Next, the operation of the TDM transmission processing unit 102 of the TDM interface board (100-2) will be described.

  The depacketizer 140 uses the port number of the device packet 502 received from the packet switch 300 from the transmission table 150 as the header search information 412 using the source local address, the Ethernet header Type value, and the MPLS-TP header Label value. The channel information 413 including the path number and channel number is searched. Depacketization section 140 performs depacketization, generates TDM signal 410, and transmits it to TDM transmission section 160 with channel information 413. The TDM transmitter 160 outputs a TDM signal 411 according to the port number, path number, and channel number obtained from the transmission table 150.

  Finally, the operation of the packet transmission unit 202 of the packet interface board (200-2) will be described.

  The header changing unit 240 uses the transmission source table 250 as the header search information 432 for the transmission source local address, the Ethernet header Type value, and the MPLS-TP header Label value of the in-device packet 503 received from the packet switch 300. The header information 433 including the number, the destination MAC address, and the source MAC address is searched. The header changing unit 240 changes the destination MAC address and the source MAC address obtained from the transmission table 250, and gives the packet 430 to the packet transmitting unit 260 together with the port number. The packet transmission unit 260 transmits the given packet 431 to the port number obtained from the transmission table 250.

(A-3) Effect of Embodiment According to the transmission signal processing device of the above embodiment, when transmitting the in-device packet from the TDM interface board or the packet interface board to the packet switch, the MPLS packet format is unified, and the TDM port In the case of interconnection between devices, the value of a dummy label (including line specifying information that defines a port number, a pass number, a channel number, etc.) for specifying the line of the interface board on the device output side is used as the MPLS-TP header. By assigning to the Label value, it is possible to realize not only switching between TDM ports and packet ports, but also switching between TDM ports as well as switching between TDM ports with a configuration of only one packet switch.

  Here, in the case of switching between the TDM port and the packet port and between the packet ports, “0x8847” generally used in the case of the MPLS packet is added to the Type value of the Ethernet header, In the case of switching, it is possible to determine whether the value is a Label value or a dummy label value by adding “0xFFFF” (other values not applied in label switching may be applied). Can be performed appropriately.

  Further, since the packet converted from the TDM signal switched from the TDM port to the packet port is an MPLS packet, it can be sent as it is to the network according to the MPLS-TP packet transfer method.

(B) Other Embodiments In the above embodiment, the input packet to the transmission signal processing device and the output packet from the transmission signal processing device are MPLS packets having an MPLS-TP header. -A packet having no TP header may be an input / output packet. In this case, an MPLS-TP header adding unit may be provided at the input stage, and an MPLS-TP header removing unit may be provided at the output unit.

  In the above-described embodiment, the interface unit has an interface board configuration. However, the interface unit may be configured by other than a board (for example, a card or an LSI).

  In the embodiment described above, switching between boards has been mainly described, but each unit may perform other processing in addition to the processing described above. For example, the packet reception unit 210 may discard an input packet that exceeds the time specified by the TTL field.

1 ... transmission signal processing device,
DESCRIPTION OF SYMBOLS 100 (100-1, 100-2) ... TDM interface board, 101 ... TDM reception process part, 102 ... TDM transmission process part, 110 ... TDM reception part, 120 ... Packetization part, 130 ... Reception table, 140 ... Depacket Conversion unit, 150 ... transmission table, 160 ... TDM transmission unit,
200 (200-1, 200-2) ... Packet interface board, 201 ... Packet reception processing unit, 202 ... Packet transmission processing unit, 210 ... Packet reception unit, 220 ... Header replacement unit, 230 ... Reception table, 240 ... Header Replacement unit, 250 ... transmission table, 260 ... packet transmission unit,
300: Packet switch.

Claims (3)

A packet switch for switching packets of a predetermined format;
A TDM input interface unit for processing an incoming TDM signal;
A TDM output interface unit for performing output processing of a TDM signal obtained by depacketizing a packet from the packet switch;
A packet input interface unit that processes incoming packets and gives them to the packet switch;
A packet output interface unit that performs output processing of a packet given from the packet switch;
The TDM input interface unit converts an incoming TDM signal into a packet of the predetermined format, and if the destination interface unit from the packet switch is the TDM output interface unit, a line in the TDM output interface unit Packets to which packet identification information is added and packetized to the packet switch, and when the destination interface unit from the packet switch is the packet output interface unit, the packet to which line identification information is added in the packet output interface unit transmission signal processing device into packets and having a packetizing means Ru applied to the packet switch.   2. The transmission signal processing according to claim 1, wherein the packet of the predetermined format is a packet according to an MPLS-TP packet transfer method, and the line specifying information is given to a Label field of an MPLS-TP header. apparatus.   3. The transmission signal processing apparatus according to claim 2, wherein a value for distinguishing whether or not the line specifying information is assigned to a Label field is assigned to the Type field of the Ethernet header of the packet.

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