JP2001144777A - Method for converting address for atm exchange network using atm exchange and x.25 packet terminals - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for converting address for an ATM exchange network using an ATM exchange and X.25 packet terminals, by which a packet call is routed in the ATM exchange network when the X.25 packet terminals for setting a VC call are connected to the network. SOLUTION: The method is characterized in such a way that an X.25/ATM address table in a CLAD device arranged in the ATM exchange is retrieved with an originating/receiving DTE address as an index key when VC calling is executed from the X.25 packet terminal (a) to the terminal (b) or (c) through the ATM exchange network, applying ATM-PVC is assigned and cell conversion is executed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ATM switch and an X.264 switch.
The present invention relates to an address conversion method for an ATM switching network using 25 packet terminals.

[0002]

2. Description of the Related Art Conventionally, a synchronous transfer mode (hereinafter referred to as ST) has been known.
M). 25 packet terminals have been manufactured and used on the assumption that they are connected to a packet switching network. However, recently, the ATM switching network has been introduced as a main information network instead of the packet switching network. This is because the information network based on the ATM switching network can efficiently transfer information and the like whose bit rates differ greatly from low speed to high speed as compared with the conventional STM.

[0003]

However, since the addressing system used in the packet switching network is different from the addressing system used in the ATM switching network, the X.264 protocol conventionally used in the ATM switching network has been used. When using 25 packet terminals, a CLAD device had to be used. This CLAD device is a device mainly having a function of providing cell disassembly and assembly for non-ATM communication equipment and a frame relay switching function. That is, the packet switching network (X.25) is used by both of these functions of the CLAD device.
And a high-quality trunk network (frame relay network) for SINET (TCP / IP) and a process of transferring it to an ATM network were required. Specifically, the layer of the logical network viewed from the packet switching network and the SINET is such that a frame relay network is put on an ATM network, It was necessary to make a complicated construction such as applying a protocol such as 25 or TCP / IP. Therefore, in an environment in which an ATM switching network is laid, the conventional X.100 is used. There is a problem that 25 packet terminals cannot be used as they are.

[0004] The present invention has been made in view of the above-mentioned problems in the prior art, and has been made in view of the above X. 25
When packet terminals are connected to an ATM switching network,
An ATM switch which enables routing of packet calls in the ATM switching network; It is an object of the present invention to provide an address conversion method for an ATM switching network using 25 packet terminals.

[0005]

An ATM switch according to a first invention of the present application, which is provided to solve the above-mentioned problems, is an ATM switch.
CLAD connected by M switching network and provided inside
X. through the device 25 packet terminal is connected, and the CLAD device is connected to the X.25 terminal. X.25 that performs address conversion between ATM and ATM. 25 / ATM address table is provided.

[0006] X.X. 25 / ATM address table, the VCI / VPI in ATM-PVC and X.25. DTE and LC at 25
The N / LCGN can be correlated 1: 1 to enable routing of packet calls within the ATM switching network.

[0007] According to the second aspect of the present invention, which is provided to solve the above-mentioned problems, the X.264 standard is used. An address conversion method for an ATM switching network using a 25-packet terminal is described in one X.25. 25 through the ATM switching network from another X.25 packet terminal. When a VC call is made to a 25-packet terminal, the incoming / outgoing DTE address is used as an index key,
X.X in the CLAD device provided in the ATM exchange. 25 /
Searches the ATM address table and finds the corresponding ATM-P
It is characterized in that VCs are allocated and cells are formed.

By adopting such a method, after the packet is identified, the address can be converted by the address table. The 25-packet terminal can be used in the same way as when it is connected to a packet switching network.

[0009] According to the third aspect of the present invention, which is provided to solve the above-mentioned problem, the present invention relates to X.264. The address conversion method of the ATM switching network using the 25-packet terminal uses the LCN / LCGN described on the CR packet header at the time of calling the VC, by using the calling / receiving DT on the address table in the CLAD device accommodated by the calling terminal.
LCN / of the corresponding item indexed using the E address as a key
It is characterized by overwriting the LCGN.

By adopting such a method, CLAD
Since packet identification can be performed by the device, it is possible to perform address conversion using an address table. Here, the LCN / LCGN is a logical channel number / logical channel group number, and is originally given to a specific call when an X25 packet terminal is connected to a packet switching network. Accordingly, this has a function of enabling routing within the packet switching network.

[0011] According to the fourth aspect of the present invention, which is provided to solve the above-mentioned problem, X.X. The address conversion method of the ATM switching network using the 25-packet terminal is described in the following.
, And this is described in the CN packet header and the address table in the CLAD device.

By employing such a method, CLAD
Since packet identification can be performed by the device, it is possible to perform address conversion using an address table.

[0013] According to the fifth aspect of the present invention, which is provided to solve the above-mentioned problem, X.A. The address conversion method of the ATM switching network using the 25-packet terminal uses the D
LCN / LCGN described on T packet header
Is used as an index key to assign a corresponding ATM-PVC.

At the time of DT packet transfer, by assigning a corresponding ATM-PVC using LCN / LCGN described on the DT packet header as an index key, C
Since packet identification can be performed by the LAD device,
It is possible to perform address conversion using an address table.

[0015] According to a sixth aspect of the present invention, there is provided an X.509 system for solving the above problems. An address conversion method for an ATM switching network using 25 packet terminals is characterized by converting an I frame into an ATM cell.

By converting an I frame into an ATM cell, X. 25 packet terminals are V
When setting C call, DTE address and LCN / LCGN and A
Address resolution with VCI / VPI in TM-PVC can be performed. Therefore, X. The 25-packet terminal can be used in the ATM switching network in the same way as when it is connected to the packet switching network.

[0017]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of an ATM switch according to the present invention; A configuration of an embodiment of an address conversion method for an ATM switching network using 25 packet terminals will be described with reference to the drawings. FIG. 1 (a) shows A according to the present invention.
FIG. 1B is a block diagram showing a network configuration of an embodiment of the TM exchange, and FIG. 1B is a diagram showing an address table provided in the CLAD device. As shown in FIG. 1A, an ATM exchange according to the present invention uses an X.D. Each of the ATM switches connected to the 25 packet terminals is connected by an ATM switching network.
That is, the ATM switch A is connected to the X.A. through the CLAD device A1 provided therein. 25 packet terminal a is connected, and ATM switch B has C
X. Via the LAD device B1. 25 packet terminals b are connected. The ATM exchange C is connected to the X.A. through a CLAD device C1 provided therein. 25 packet terminals c are connected, and ATM exchange A and ATM exchange B
And the ATM switch C are connected by an ATM switching network. Further, the CLAD device is shown in FIG.
(B) has an address table as shown in FIG. 25
And a user interface part of LAPB.

The CL of the ATM exchange according to the present invention is
The AD device has the following functions. (1) A function of allocating VCI / VPI values on an address table searched using the originating and destination DTE addresses in the CR / CN / CC / CA / CQ / CI / CF packet data header as index keys. (2) LCN / LC described in CR packet header
A function to describe, that is, overwrite, the GN value in the LCN / LCGN item on the address table searched using the destination address as the index key. (3) A function of allocating a V / X terminal physical line based on the originating DTE address in each CC / CF packet header. (4) A function of allocating a physical line of a V / X terminal based on the originating DTE address in each packet header of the CN / CF. (5) LCN / LC described in DT packet header
A function of allocating VCI / VPI values on the address table searched using the GN value as an index key. (6) DT / RR LCN / LCGN in each packet header
For assigning a V / X terminal physical line according to (7) When the C / N packet arrives at the destination CLAD device, the destination terminal-accommodating CLAD device pays out the LCN / LCGN value and sets the LCN / LCGN field on the CN packet header. (8) LCN paid out by the CLAD device accommodating the receiving side terminal
/ LCGN value is retrieved using the originating and destination DTE address on the CN packet header on the address table as a key.
Function to set for N / LCGN field. (9) A function of setting the LCN / LCGN value on the address table searched using the VCI / VPI value as an index key, on the DT / RR packet header. (10) A function of performing a judgment branch process based on the packet type identification in the packet header. (11) Function to convert one frame into cells or non-cells. (12) X. 25 A function to establish a data link between the packet terminal and the CLAD device. (13) X.X. A function of transmitting a PR frame to a 25-packet terminal. The functions described above are described in the following X.X. The operation of an embodiment of an address conversion method for an ATM switching network using 25 packet terminals will be described with reference to FIG.

Next, according to X.A. The operation of one embodiment of the address conversion method for the ATM switching network using 25 packet terminals will be described below with reference to FIGS. FIG. X.25 in an embodiment of an address conversion method for an ATM switching network using a 25-packet terminal. It is a block diagram which shows the communication operation between 25 packet terminals. FIG. 2
It is a block diagram which shows the relationship between the address conversion table and each process in one Embodiment of the address conversion method of ATM switching network using 5 packet terminals. Further, FIG.
X. According to the present invention. FIG. 4 is a block diagram showing an I-frame cell conversion means in an embodiment of an ATM switching network address conversion method using 25 packet terminals. As shown in FIG. 25 packet terminal a and X.25 The 25-packet terminal b completes the data link setting by exchanging the built-in CLAD devices A1 and B1 with the SABM and the UA.

(Processing A11) X.25 packet terminal a. X.25 packet terminal b. When a CR packet for setting 25 paths is transmitted, In the CLAD device A1 accommodated in the 25-packet terminal a, C
When the R packet is received, it is determined that the packet type identifier in the packet header is CR as shown in FIG. Thereafter, the address table in the CLAD device A1 is searched by using the originating and destination DTE address set in the CR packet as an index key, and the corresponding VCI / VPI is allocated, and the cell is formed as shown in FIG. 4 and transmitted to the ATM exchange side. At this time, as shown in FIG. 3, the LCN / LCGN written in the CR packet is overwritten on the term of the incoming / outgoing DTE address on the address table. Here, in FIG. 4, the conditions at the time of cell formation are written in the condition part in the ATM cell. For example, I frame length, packet length, SEQ number in the same frame, and the like.
At the same time, as shown in FIG.
Then, X. The RR frame is transmitted to the 25-packet terminal a.

(Process B11) As shown in FIG.
After the cell arrives at the CLAD device B1, the cell is decellulated and packetized, and as shown in FIG. 3, when it is determined that the packet type identifier of the packet is CN, the LCN
LCN / L paid out by the / LCGN payout function
The CGN is overwritten on the LCN / LCGN of the CN packet. At the same time, it overwrites the LCN / LCGN column searched using the incoming / outgoing DTE address set on the address table in the CLAD device B1 as an index key, and assigns a physical terminal line corresponding to the call. The packet is transmitted to the 25-packet terminal b.

(Process B12) Next, as shown in FIG.
X. When the CLAD device B1 receives the CA packet transmitted from the 25-packet terminal, the CLAD device B1
Then, the packet type identifier is determined to be a CA packet, a search is made for the incoming / outgoing DTE address group in the CA packet as an index key, and the corresponding VCI / VPI is assigned to make a cell. At this time, as shown in FIG.
In the LAD device B1, the RR frame is set to X.25. Sent to 25 packet terminals.

(Process A12) As shown in FIG.
In the CLAD device A1 where the cell arrives, after decellularizing and packetizing, as shown in FIG. 3, if it is determined that the packet type identifier of the packet is CC, the VCI / VPI before decellularizing is determined. LCN / L on address table in CLAD device A1 searched as index key
Overwrite the CGN on the LCN / LCGN on the CC packet, assign a physical terminal line corresponding to the calling DTE address of the call, The packet is transmitted to the terminal 25a. Thereby, X. 25 packet terminal a and X.25 A path between the packet terminal 25 and the packet terminal b is set.

(Process A13) Thereafter, as shown in FIG. X.25 packet terminal a. When transmitting data to the X.25 packet terminal b, X.25 The DT packet transmitted from the 25-packet terminal a is transmitted to the CLAD device A1.
, When it is determined that the packet is a DT packet by looking at the packet type identifier, the address table in the CLAD device A1 is searched using the LCN / LCGN in the packet as an index key, and the corresponding VCI / VPI is allocated and cellized. , To the ATM exchange side. At this time, as shown in FIG. The RR frame is transmitted to the 25-packet terminal a.

(Process B13) As shown in FIG.
In the CLAD device B1 where the cell arrives, after decellularization and packetization, if it is determined that the packet type identifier of the packet is DT as shown in FIG. 3, the VCI / VPI before decellulation is indexed. LCN / LCGN on the address table in CLAD device A1 as D
Overwrite the LCN / LCGN on the T packet and assign the corresponding physical terminal line on the address table. 2
5 Transmit to the packet terminal b side.

(Process B14) As shown in FIG. 2
X.5 packet terminal b. X.25 when transmitting data to the packet terminal a. When the CLAD device B1 receives the RR packet transmitted from the 25-packet terminal b and determines that the packet is an RR packet by looking at the packet type identifier, the address table in the CLAD device B1 is set using the LCN / LCGN in the packet as an index key. And assigns the corresponding VCI / VPI, converts it into a cell, and transmits it to the ATM exchange as shown in FIG. At this time, as shown in FIG. 2
The RR frame is transmitted to the 5-packet terminal b.

(Process A14) As shown in FIG.
In the CLAD device A1 where the cell has arrived, after decellularizing and packetizing, as shown in FIG. 3, when it is determined that the packet type identifier of the packet is RR, the VCI / VPI before decellularizing is determined. LCN / L on address table in CLAD device A1 searched as index key
Overwrite the CGN on the RR packet, assign the corresponding physical terminal line on the address table, The packet is transmitted to the terminal 25a.

(Process A15) Next, as shown in FIG.
X. When a CQ packet for path disconnection is received from the packet terminal a, X.25. When the CLAD device A1 accommodated in the 25-packet terminal a determines that the packet type identifier is CQ, the transmission / reception DTE in the CQ packet is determined.
The address table is searched using the address set as an index key, the corresponding VCI / VPI is assigned, the cell is formed as shown in FIG. 4, and the cell is transmitted to the ATM exchange side. At this time,
As shown in FIG. 25 to the packet terminal a side.

(Process B15) As shown in FIG.
In the CLAD device B1 where the cell arrives, after decellularization and packetization, as shown in FIG. 3, when it is determined that the packet type identifier of the packet is CI, a search is performed using the originating and destination DTE address pair as an index key. Assign a physical terminal line, X. The packet is transmitted to the 25-packet terminal b.

(Process B16) Next, as shown in FIG.
X. When the CLAD device B1 receives the CF packet transmitted from the 25-packet terminal b, the CLAD device B1
Then, the packet type identifier is determined to be a CF packet, the address table is searched using the originating and destination DTE address group in the CF packet as an index key, and the corresponding VCI
/ VPI, and cell as shown in FIG.
It is transmitted to the M exchange. At this time, as shown in FIG.
In the LAD device B1, the RR frame is set to X.25. The packet is transmitted to the packet terminal b side.

(Process A16) As shown in FIG.
In the CLAD device A1 where the cell arrives, after the cell is decellularized and packetized, as shown in FIG. 3, when it is determined that the packet type identifier of the packet is CF, the physical address corresponding to the originating and terminating DTE address of the call is determined. Assign a terminal line, X. The packet is transmitted to the terminal 25a. Thereby, X. 25 packet terminal a and X.25 25 packet terminals b
Is disconnected.

[0032]

As described above, according to the present invention.
According to the ATM switch and the address translation method using the 25-packet terminal, the terminal accommodating CLAD device performs address resolution by the address table by identifying the packet, and converts the I frame into ATM cells or non-cells. 25 When a packet terminal establishes a VC call even in an ATM switching network, the DTE address and the LCN /
Address resolution between LCGN and VCI / VPI in ATM-PVC can be performed. Therefore, X. The 25-packet terminal can be used in the ATM switching network in the same way as when it is connected to the packet switching network.

[0033]

[Brief description of the drawings]

FIG. 1 is a block diagram showing a network configuration in an embodiment of an ATM exchange according to the present invention.

FIG. A using 25 packet terminals
In one embodiment of the address conversion method of the TM switching network, the X.400 is used. It is a block diagram which shows the communication operation between 25 packet terminals.

FIG. A using 25 packet terminals
FIG. 3 is a block diagram illustrating a relationship between an address conversion table and each process in an embodiment of an address conversion method for a TM switching network.

FIG. A using 25 packet terminals
FIG. 2 is a block diagram showing an I-frame cell forming means in an embodiment of an address conversion method of a TM switching network.

[Explanation of symbols]

 A. ATM switch B. ATM switch C. ATM exchange A1. CLAD device B1. CLAD device C1. CLAD device a. X. 25 packet terminals b. X. 25 packet terminals c. X. 25 packet terminals

Claims (6)

[Claims] 1. An X.509 system connected via an ATM switching network and via a CLAD device provided therein. 25 packet terminal is connected, and the CLAD device is connected to the X.25 terminal. X.25 that performs address conversion between ATM and ATM. 25 / ATM switch provided with an ATM address table. 2. An X. 25 through the ATM switching network from another X.25 packet terminal. When a VC call is made to a 25-packet terminal, the call originating and terminating DTE address is used as an index key, and X.25 in the CLAD device provided in the ATM exchange is used. X.25 / ATM address table is searched, and the corresponding ATM-PVC is allocated and cellized. Address conversion method for ATM switching network using 25 packet terminals. 3. The LCN / LCGN of the corresponding term obtained by indexing the LCN / LCGN described on the CR packet header at the time of calling a VC with the calling / receiving DTE address in the address table in the CLAD device accommodating the calling terminal as a key. 3. The method according to claim 2, wherein the data is overwritten. Address conversion method for ATM switching network using 25 packet terminals. 4. The method according to claim 1, wherein, when the VC is originated, the called terminal terminal-accommodated CLAD device issues an LCN / LCGN for the corresponding call, and this is described in a CN packet header and an address table in the CLAD device. Item X.3. Address conversion method for ATM switching network using 25 packet terminals. 5. The method according to claim 2, wherein at the time of transferring the DT packet, a corresponding ATM-PVC is assigned using LCN / LCGN described on the DT packet header as an index key. X. of the description. Address conversion method for ATM switching network using 25 packet terminals. 6. The method according to claim 2, wherein the I frame is converted into an ATM cell. 2
Address conversion method for ATM switching network using 5 packet terminals.