JPH0715432A - Frame relay switching network test method - Google Patents

Abstract

(57) [Abstract] [Purpose] Regarding the frame relay switching network test method of a frame switch consisting of a switch, a trunk line accommodating unit, and a terminal accommodating unit, even if a terminal is not connected to each switch, the set P
The purpose is to verify that a frame flows along a route of a VC (logical line). [Structure] In a frame exchange comprising a switch unit 5, a trunk line accommodation unit 6, and a terminal accommodation unit 4, in the terminal accommodation unit 4
Means for generating a test frame, means for returning an outgoing route to the terminal accommodating portion 4, means for writing an identifier for identifying each accommodating portion in the test frame in the terminal accommodating portion 4 and the trunk line accommodating portion 6, or The relay line accommodating unit 6 has means for writing an identifier for identifying the switch unit 5 to which each accommodating unit belongs to the test frame, or means for writing an identifier for identifying a physical line connected to each accommodating unit in the test frame. Means for turning back the outgoing route to the relay line accommodation section 6 and terminal accommodation section 4
And means for reading the test data description area in the test frame.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a frame relay switching network test system for a frame switch which comprises a switch, a trunk line accommodation section and a terminal accommodation section. A frame switch is a switch that connects and exchanges frame information by setting the frame identification code between the set terminals, between terminals, between terminals and relay lines, and between relay lines and relay lines. (PVC) is accommodated and multiplex exchanged.

A functional block diagram of a frame exchange is shown in FIG. In the figure, 21 is a terminal group, 22 is a relay line group, 23 is a frame switch, 24 is a terminal accommodating unit, 25 is a relay line accommodating unit,
Reference numeral 26 is a node control unit, and 27 is a switch unit. Functionally, the frame switch 23 is roughly divided into three parts: a terminal housing part 24
It is divided into a line accommodating section 25 and a switch section 27, and has a function of controlling the node and the operation of the switch section.

The switch unit 27 has a function of reconnecting the lines so that the frames are sent to an appropriate line according to the destination of the frame input from a certain line.
Has a function of an interface for connecting a physical line from a terminal to the switch unit 27, and the trunk line accommodating unit 25
Has a function of an interface for connecting a physical line connecting switches to a switch.

[0004] Such a switch unit 27 and a trunk line accommodation unit
A network composed of a frame switch composed of 25 and a terminal accommodating section 24 is called a frame relay switching network. The frame format of this frame relay is shown in FIG. The frame relay is composed of a flag indicating the start and end of a frame, a DLCI (identification code) in the header part, and an information part that accommodates data, and is transferred at high speed along a PVC (logical line).

Unique addresses are assigned to the trunk line accommodation section 25 and the terminal accommodation section 24, and the switch section 27 has information for performing routing therein. This information is a table showing what DLCI is attached to which direction in what direction to look at the DLCI of the header of the incoming frame. The switch unit 27 looks at this table and the trunk line accommodation unit 25 or the terminal accommodation unit 24
The frame coming in from is sent to another trunk line accommodation unit 25 or terminal accommodation unit 24.

The line accommodating unit 25 on the relay side is an interface for electrically connecting a terminal and a physical line, and has a function of writing data in a passing frame and a frame received by a switch by returning an outgoing route. It has the function of sending back. The terminal accommodation unit 24 on the terminal side is an interface that electrically connects the terminal and the switch, and the terminal accommodation unit 24 further has a function of generating a test frame and a function of writing data in the passing frame. By returning the output path, it has the function of returning the frame received from the switch.

[0007]

2. Description of the Related Art FIG. 5 shows an example of the connection configuration of a conventional frame relay switching network. In the figure, 31 is a terminal, 32 is a frame switch, 33 is a routing table, and 34 is a routing table. In the routing table 33,
LCI, outgoing route, outgoing DLCI are routing table
It is stored as shown in 34. The DLCI is an identification number attached to the path to the next exchange to be transferred.

The switch part of the frame exchange 32 reads the DLCI value "16" in the frame from the terminal 31, uses the routing table 34, and switches the frame in either direction from the read DLCI value "16". Decide whether to do (outgoing route C). And a new DL in the frame
The CI value "105" is reset and transmitted. Therefore, the direction of the trunk line C is selected and transmitted, and the DLCI value "16" is selected from the DLCI value "105" returned by the trunk line C to select the terminal.
Returned to 31.

Logical circuit PVC of frame relay switching network
Is a virtual path set from a certain terminal to another terminal and is set in advance before the network starts operation.
Since the logical line PVC is a virtual line, a plurality of logical lines PVC are provided on the physical line. Each exchange refers to the DLCI value in the header of the frame received from the PVC, and reattaches the DLCI to the next destination from the routing table of the exchange and transmits it.

[0010] Here, the DLCI only needs to be matched in outgoing and incoming between the adjacent exchanges, and it is not necessary to use the same DLCI value over the entire PVC. However, the PVC has the same DLCI value on the upstream side and on the downstream side if the same exchange is used. Therefore, the DLCI value from the terminal 31 to the exchange 32 is "16" for the input and output, and the DLCI value for the next exchange via the exchange 32 and the trunk line C is "105" for the input and output.

[0011]

Conventionally, the frame exchange has a method of checking whether or not the routing table is correct so that the routing is properly performed, and correcting it if it is not correct. In addition, in order to confirm that the frame is flowing along the PVC, the standard frame format is changed and the test is performed by adding the additional information for the test of the frame, or the exchange is equipped with a terminal having a test function. I had to connect.

When configuring the network, all PVs set
It is necessary to have a means to confirm that C correctly flows the frame. In order to confirm that the frame correctly flows to the set PVC, it is necessary to verify that the routing table in the switch unit is correct and that the operation of the hardware operating according to the routing table is also correct.

In the prior art, there was a means for confirming whether or not the routing table was correct, but in confirming the operation of the hardware, if the frame format was changed for the test, the switch itself exchanging the standard frame was checked. I couldn't say that I was verifying it, but if I didn't change the frame format, I had to connect a terminal with a test function to the exchange.

Therefore, according to the present invention, even if a terminal such as a router is not connected to the exchange, there is provided means for confirming the correctness of the operation of the switch, including the hardware that flows the frame of the standard frame format according to the routing table. The purpose is to develop a test method to have.

[0015]

FIG. 1 is a block diagram showing the principle of the present invention. In the figure, 1 is an originating exchange, 2 is a relay exchange, 3 is a destination exchange, 4 is a terminal accommodating section, 5 is a switch section, and 6 is a trunk line accommodating section.

A means for generating a test frame in the terminal accommodating section 4, a means for returning the outgoing path to the terminal accommodating section 4, and an identifier for identifying each accommodating section in the test frame in the terminal accommodating section 4 and the trunk line accommodating section 6. A means for writing a message or the terminal accommodating portion 4
And means for writing an identifier for identifying the switch section 5 to which each accommodation section belongs to the trunk line accommodation section 6, or an identifier for identifying a physical line connected to each accommodation section for the terminal accommodation section 4 and the trunk line accommodation section 6. Have means.

Means for returning the outgoing route to the trunk line accommodation unit 6, means for reading the test data description area in the test frame into the trunk line accommodation unit 6 and the terminal accommodation unit 4, the relay line accommodation unit 6 and the terminal accommodation A means for judging that the frame has flowed in the same direction a plurality of times in the same accommodating section in the section 4, or a means for monitoring the number of hops from the place generated in the frame in the trunk circuit accommodating section 6 and the terminal accommodating section 4. Equipped with.

[0018]

In the originating exchange 1, a test frame is generated in the terminal accommodating section 4, an identifier for identifying the terminal accommodating section 4 is written in the test frame, and the switch section 5 to which the trunk line accommodating section 6 belongs is written in the test frame. The identifier is written, the identifier of the physical line connected to the trunk line accommodation unit 6 is written in the test frame, and the identifier for identifying the trunk line accommodation unit 6 is written in the test frame in the transit exchange 2.
The identifier of the switch unit 5 to which the trunk line accommodation unit 6 belongs is written in the test frame, and the identifier of the physical line connected to the trunk line accommodation unit 6 is written in the test frame.

In the destination exchange 3, the identifier for identifying the trunk line accommodation section 6 is written in the test frame, the identifier of the switch section 5 to which the terminal accommodation section 4 belongs is written in the test frame, and the terminal accommodation section is written in the test frame. 4, the identifier of the physical line connected to the terminal 4 is written back, the output path of the terminal accommodation unit 4 is folded back, the identifier for identifying the trunk line accommodation unit 6 is written in the test frame, and the switch unit to which the trunk line accommodation unit 6 belongs in the test frame. The identifier 5 is written, and the identifier of the physical line connected to the trunk line accommodation unit 6 is written in the test frame.

In the repeater exchange 2, the identifier for identifying the trunk line accommodation unit 6 is written in the test frame, the identifier of the switch unit 5 to which the trunk line accommodation unit 6 belongs is written in the test frame, and the trunk line accommodation unit is written in the test frame. Part 6
, The identifier of the relay line accommodating section 6 is written in the test frame, and the identifier of the switch section 5 to which the terminal accommodating section 4 belongs is written in the test frame. The identifier of the physical line connected to the terminal accommodation unit 4 is written in the frame, the test data description area in the test frame is read in the terminal accommodation unit 4, and the normality of the test frame data is verified.

If there is a failure such as a line disconnection between the repeater exchange 2 and the destination exchange 3, the call is returned at the outgoing route of the repeater exchange 1 and the test frame up to the repeater exchange 2 is returned to the originating exchange 1. Check the abnormality. If a certain exchange judges that the same test frame has flowed in the same direction multiple times due to some failure in this exchange, the outgoing route is turned back and the test frame is sent back to the originator. To confirm. The number of hops from the place where the frame was generated in each exchange is judged from the data in the frame, and the output route is returned by the exchange that has exceeded the specified value, and the test frame returns to the generation source and an error occurs in the originating exchange. To judge.

[0022]

FIG. 2 shows an embodiment of the frame relay switching network test system of the present invention. In the figure, 11 is the originating exchange A, 12
Is a relay exchange B, 13 is a relay exchange C, 14 is a destination exchange D, 15 is a destination exchange E, 16 is a terminal accommodating unit, 17 is a switch unit, 18 is a relay line accommodating unit, 19 is a physical line, and 20 is Indicates a logical line.

Let the terminal accommodating portion 16 of the originating exchange A located at the beginning of the PVC 20 to be tested be a. The PVC is stretched so as to connect from the originating exchange A through the transit exchanges B and C to the destination exchange D as shown by the dotted line in the figure, and the test frame generated in a flows along the PVC. To go. When passing through the exchange, the line accommodation unit writes an ID for identifying each accommodation unit in the information field of the test frame.

Since the terminal of the PVC 20 is folded back at the terminal accommodating portion 16, the test frame enters the down line. PVC20
Has the same DLCI value on the upstream and the downstream, so it is expected to return on the same path. By checking the contents of the frame that has returned to the starting point a, it is possible to verify whether or not the bus is passing as set.

When a failure occurs on the physical line 19,
The line is returned to the frame by returning to the line accommodating section immediately before the failure occurrence section. In this case, it will be returned in the middle of the PVC, but since the DLCI value is the target for the upstream line and the downstream line, the same path is returned. Further, when the frame goes around the loop in the middle, it is judged from the history data described in the frame that the line accommodating section on the loop has been turned a finite number of times, and then it returns and returns. Alternatively, an upper limit may be set for the number of hops in which a frame flows from the trunk line accommodation unit 18 to the next trunk line accommodation unit 18, and when a certain number of hops is reached, the frame may return with a timeout.

As described above, the frame is PV between the line accommodating portion a at the beginning of the PVC and the line accommodating portion h at the end of the PVC.
It can be confirmed that it is flowing along C. Further, as shown in FIG. 3, the operation of the terminal accommodating unit can be verified by confirming that the frame flows between the terminal and the node control unit by a method such as a link management procedure. The legitimacy of the trunk line accommodating section can be verified by exchanging control information between the node control section and another node control section and confirming that data flows. Then, if these three methods can be used, it is possible to verify that the frame flows as set for the entire PVC.

[0027]

According to the verification means of the present invention, it is possible to verify that a frame flows along the set PVC path even if each exchange is not equipped with a terminal. Further, even if a failure occurs in the physical line, it is possible to check up to where in the PVC the frame has flowed. Furthermore, when the frame loops in the network, the place where the loop occurs can be examined, and even if the frame randomly flows in the network, it can be stopped halfway.

As is apparent from the above, the application of the present invention has the effect of verifying the correctness of the operation of the frame relay switching network.

[Brief description of drawings]

FIG. 1 is a block diagram of the principle of the present invention.

FIG. 2 Example of frame relay switching network test system

FIG. 3 is a functional block diagram of a frame exchange.

[Figure 4] Frame relay frame format

FIG. 5 is a connection configuration example of a conventional frame relay switching network.

[Explanation of symbols]

 1,11 Originating switch 2,12,13 Transit switch 3,14,15 Terminating switch 4,16,24 Terminal accommodating part 5,17,27 Switch part 6,18,25 Relay line accommodating part 19 Physical line 20 Logical Line 21 Terminal group 22 Trunk line group 23, 32 Frame switch 26 Node controller 31 Terminal 33 Routing table 34 Routing table table

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication H04Q 11/04 9076-5K H04Q 11/04 L

Claims (3)

[Claims] 1. A frame exchange comprising a switch section (5), a trunk line accommodation section (6) and a terminal accommodation section (4), and means for generating a test frame in the terminal accommodation section (4).
Means for turning back the outgoing route to the terminal accommodating part (4), means for writing an identifier for identifying each accommodating part in the test frame in the terminal accommodating part (4) and the trunk line accommodating part (6), or the test frame In the test frame, there is provided means for writing an identifier for identifying the switch section (5) to which each accommodation section belongs, or means for writing an identifier for identifying a physical line connected to each accommodation section in the test frame. ) And a means for reading the test data description area in the test frame in the terminal accommodating section (4), and the PVC is provided in the terminal accommodating section (4) of the originating exchange (1).
A frame relay switching network test method characterized by verifying that a frame flows through (logical line). 2. In the frame exchange, a means for reading the test data description area in the test frame into the trunk accommodation unit (6) and the terminal accommodation unit (4) and a plurality of accommodating units having the same test frame are provided. 2. The frame relay switching network test system according to claim 1, further comprising means for determining that the flow has flowed in the same direction once. 3. In the frame exchange, means for reading the test data description area in the test frame into the trunk accommodation unit (6) and the terminal accommodation unit (4), and a means for reading the test data description area from the location generated in the test frame. The frame relay switching network test method according to claim 1, further comprising: means for monitoring the number of hops.