JP3347701B2 - ATM transmission equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ATM transmission device connected to an ATM line network and capable of transmitting data to an opposite device.

[0002]

2. Description of the Related Art FIG. 8 is a block diagram of a conventional ATM data transmission device. The central processing unit 1 manages and controls all the devices. SAR (Segmentation and Reassembly) Part 2
Assembles / disassembles data packets to be transmitted into ATM cells. The communication terminal 101 is connected to the terminal I / F unit 3. The ATMi / f unit 5 is physically connected to the ATM network 102 and takes in a transmission packet according to a virtual path identifier (hereinafter, VPI) and a virtual channel identifier (hereinafter, VCI) of the cell. This ATM data transmission device is an ATM network 10
The communication with the opposing device 103 is performed via the communication device 2.

[0003] A terminal I / F cable 201 is an RS232 cable.
C, LAN, etc., the communication terminal 101 and the terminal I /
F section 3 is connected. The transmission line 202 connects the terminal I / F unit 3 and the SAR unit 2. The transmission line 203 connects the SAR unit 2 and the ATMi / f4. The line cable 204 is an ATM
The network 102 is connected to ATMi / f4.

[0006] The communication between the communication terminal 101 and the opposing device 103 via the ATM network 102 is realized by the device having the above configuration. First, uplink data transmission from the device will be described. The transmission data from the communication terminal 101 is
/ F3, and is transmitted to the SAR unit 2. The SAR unit 2 stores the received transmission data in the payload portion of the ATM cell without any modification. The ATM cell is transmitted via the line cable 204 to the ATMi.
/ F unit 4 and converted into a physical interface (OC3, ATM25, etc.) connected to the ATM network 102,
It is transmitted to the opposing device 103. The ATM cell from the opposite device 103 is transmitted to the ATM network 102 and the ATMi / f unit 4.
Is transmitted to the communication terminal 101 via the terminal I / F unit 3. Thus, end-to-end data communication can be performed via the ATM network 102.

[0005]

However, the conventional ATM transmission apparatus has a problem that it cannot be directly connected to an ATM network device such as an ATM router via an ATM network.

The present invention solves the above problem by using an AT
It is an object of the present invention to provide an ATM transmission apparatus capable of performing an opposite communication with an opposite apparatus having a different transmission format in a transmission apparatus connected to the M network.

[0007]

According to the present invention, there is provided an ATM transmission apparatus connected to an ATM network, comprising: a terminal interface unit connected to a communication terminal; an ATM interface unit connected to the ATM network; And a data frame conversion unit for mutually converting the data frame of the communication terminal and the data frame of the opposite device. According to this configuration, it is possible to realize the opposite communication directly connected to the opposite device by converting the data frame.

[0008] The data frame conversion unit transmits the upstream data.
During data transmission, and the upper proto have Ether Type
HDLC frame configured as information section with
Except Luo address portion and the control unit, the upper there is Ether Type
Take out the information section containing the location protocol and use LLC / SN
AAL5 with Ether Type by adding AP method header
Convert to packet payload data or Ether Type
Is configured as an information section with no upper layer protocol
Remove the address part and the control part from the HDLC frame, and
If there is no Ether Type and the information
And adds an LLC / SNAP header, Et
Convert to AAL5 packet payload data without her Type , and at the time of downlink data transmission, Ether Ty
pe remove the header from the AAL5 payload data there is address portion, a control unit, to convert the HDLC frame consists flag and by adding a frame check sequence Ether Type there information unit, or Ether Type
If there is no information section, the Ether Type is stored in advance.
By adding Ether Type extracted from storage means
By converting the HDLC frame into an HDLC frame to be formed, an HDLC terminal as a terminal device can be connected to an ATM via an ATM network.
-Ether Type between LLC / SNAP counterpart device
By transmitting, converting and characterized by being configured to allow data transmission transparency Holland without by upper protocol, and HDLC terminal as of handsets,
The Ether Type is transmitted to and from the opposite device of the ATM-LLC / SNAP system via the ATM network, and data can be transmitted in a transparent manner without depending on the upper layer protocol.

[0009] Furthermore, the data frame conversion unit, up de
When over data transmission, the address portion from the HDLC frame, except for the control unit, removed or without information unit having the Ether Type, the information unit in the payload data of AAL5 packet is not VC multiplexing formats of Ether Type converts, during a downlink transmission, without Ether Type A
Address part and control for payload data of AL5 packet
Ether Ty by adding
Information section with pe and higher-level protocol, or Eth
Consists of an information section with no upper type and no er Type
By converting the HDLC frame to be a HDLC terminal as of handsets, ATM through the ATM network -
It becomes possible to transmit data transparently to the opposite device of the VC multiplex system.

[0010]

[0011]

Embodiments of the present invention will be described below. FIG. 1 is a configuration diagram of the ATM transmission device of the present invention. The apparatus of the present invention includes a data frame conversion unit 5 for converting a data frame in addition to the conventional apparatus shown in FIG. In FIG. 1, the same portions as those of the conventional configuration are denoted by the same reference numerals.

(First Reference Embodiment) A first reference embodiment of the present invention will be described with reference to the data formats of FIGS. In the first embodiment, a device common to the present invention is used as the opposing device 103, and a communication terminal 101 equipped with a high-level data link (hereinafter, HDLC) procedure is connected to each device.

First, the data transmission procedure in the uplink direction will be described. Transmission data from the communication terminal 101 is transmitted to the terminal I / F
3 and is transmitted to the data frame converter 5. The data received from terminal I / F3 is HD
This is an LC frame format (FIG. 2A). The data frame conversion section 5 extracts the address section, the control section, and the information section (b), and
(Hereinafter, AAL5) packet payload data. This data is in AAL5 packet format Figure 2.
The packet is transmitted to the SAR unit 2 as (c), is decomposed into ATM cells every 53 bytes, and is transmitted to the opposing device 103 via the ATM network 102 via the ATMi / fF unit 4.

Next, the data transmission procedure in the downlink direction will be described. The ATM cell received from the opposite device 103 has the SAR
AAL5 packet format (Fig. 2
(C)). This data is transmitted to the data frame converter 5, and the payload portion is extracted. The data of the payload section is composed of an HDLC address section, control section, and information section shown in FIG.
x7E) and frame check sequence (FCS)
Is added to the frame, the frame is assembled as an HDLC frame, and transmitted to the communication terminal 101 which is an HDLC terminal via the terminal I / F unit 3. Thus, the ATM network 102
, Data transmission with the HDLC terminal 101 can be realized.

(First Embodiment) Next, a first embodiment will be described with reference to FIGS.

The configuration of the first embodiment is similar to that of the first embodiment.
The communication terminal 101 which is a C terminal is connected,
Reference numeral 3 denotes an AT which performs transmission by the ATM logical link control / sub-access protocol (hereinafter, LLC / SNAP) method.
M device is connected.

First, a description will be given of an uplink data transmission procedure. Transmission data from the communication terminal 101 is transmitted to the terminal I / F
3 and is transmitted to the data frame converter 5. The data received from terminal I / F3 is HD
This is the LC frame format (FIG. 3A), and the data frame converter 5 extracts the information section (b) (Ether Type and upper protocol data) excluding the HDLC address section and control section. In addition to this information part (b), L
LLC (3 octets), which is a header of the LC / SNAP scheme, and a management organization identifier (hereinafter, OUI: 3 octets) are added to form payload data (c) of an AAL5 packet. This data is transmitted to the SAR unit 2 in the AAL5 packet format (FIG.
M is decomposed as an M cell and passed through the ATMi / f
The data is transmitted to the opposing device 103 via the M network 102.

Next, in the downlink data transmission procedure, the ATH cell received from the partner
The unit 2 assembles the AAL5 packet format (d). This data is sent to the data frame converter 5
And the payload portion is extracted. The data of the payload portion is composed of LLC / OUI in the LLC / SNAP format of (c).
The OUI is deleted and an HDLC address section, a control section, a flag (0x7E) and an FCS (frame check sequence) are added to assemble an HDLC frame, and the communication terminal 101 which is an HDIC terminal via the terminal I / F section 3. Is transmitted to In this manner, the HDLC terminal 101 and the LLC / SNAP are connected via the ATM network 102.
The terminal 103 can realize data transmission in a transparent manner.

The Ether Type in FIG. 3 indicates an upper protocol of data to be transmitted higher. In the present embodiment, the data can be transmitted to the opposite device 103 and transparently, and communication can be realized without using the upper protocol. That is, according to the configuration of the present embodiment, it is possible to realize even a method without this Ether Type transmission.

(Second Embodiment) A second embodiment of the present invention will be described with reference to FIGS.

The device according to the second embodiment is a counter device 10.
LLC / SNAP terminal 1 as in the first embodiment as 3
The communication terminal 101 is a device that communicates with the communication device 03, and the communication terminal 101 connected to the device does not have a unit for notifying the upper protocol by Ether Type. That is, when the upper protocol data (b) of the HDLC frame (a) is used as the AAL5 packet (d), the Ether Type
Is registered in advance in the apparatus of the present invention (such as the storage means of the data frame conversion unit 5).

Then, the data frame conversion unit 5
When transmitting upstream to the M network 102, this Ether Type is set to AAL
5 is added to the header (c), and conversely, it is deleted during downlink transmission to the HDLC terminal 101, so that communication with the opposing device 103 can be realized.

(Second Embodiment) A second embodiment will be described with reference to FIGS.

In the second embodiment, a communication terminal 101, which is an HDLC terminal, is connected to this apparatus, and an AT 103 for performing transmission by the ATM-VC base multiplexing method is connected to the opposite apparatus 103.
M device is connected. First, an uplink data transmission procedure will be described. Transmission data from the communication terminal 101 is electrically converted by the terminal I / F 3 and transmitted to the data frame conversion unit 5. The data received from the terminal I / F3 is in the HDLC frame format (FIG. 5A)
The data frame converter 5 extracts the information part (b) (upper-layer protocol data) excluding the HDLC address part and the control part. The information section (b) is transmitted as payload data to the SAR section 2 as an AAL5 packet format (c), which is a VC multiplex format, decomposed as ATM cells, passed through the ATMi / f section 4 and via the ATM network 102. The data is transmitted to the opposing device 103.

Next, in the downlink data transmission procedure, the ATM cell received from the opposing device 103 has the SAR
The unit 2 assembles the AAL5 packet format (c) which is a VC multiplex format. This data is transmitted to the data frame converter 5, and the payload portion is extracted. The data of the payload section is obtained by adding an address section of the HDLC, a control section, a flag (0x7E) and an FCS (frame check sequence).
Assembled as an HDLC frame, and the terminal I / F unit 3
Is transmitted to the communication terminal 101, which is an HDLC terminal. In this way, the HDLC terminal 101 and the VC multiplex terminal 103 can realize data transmission transparently via the ATM network 102.

(Third Embodiment) A third embodiment will be described with reference to FIGS.

The device according to the third embodiment is a counter device 10
3 is a device that communicates with the same VC multiplex terminal as in the second embodiment, and the communication terminal 101 connected to this device is
This is a configuration for realizing communication when requesting a means for notifying an upper protocol by Ether Type. That is, the data frame converter 5 adds the Ether Type data to the upper protocol data (b) of the HDLC frame (a) for the downlink data from the ATM network 102, and
When transmitting as an HDLC frame to the ATM network 102, it is deleted so that the
3 is realized.

Third Embodiment A third embodiment will be described with reference to FIGS.

In the third embodiment, a PPP (Poi)
A communication terminal 101, which is an nt-to-Point Protocol) terminal, is connected, and an opposite device 103 is connected to an ATM device that performs transmission by the VC-PPP multiplexing method.

First, an uplink data transmission procedure will be described. Transmission data from the communication terminal 101 is transmitted to the terminal I / F
3 and is transmitted to the data frame converter 5. The data received from terminal I / F3 is PP
A P frame format (FIG. 7 (a)), the data frame conversion unit 5 takes out the address portion of the PPP, the information unit excluding the control section (b) (upper protocol). The information section (b) is transmitted to the SAR section 2 as an AAL5 packet format (c), decomposed as ATM cells, and transmitted to the opposite device 103 via the ATM network 102 via the ATMi // f section.

Next, in the downlink data transmission procedure, the ATM cell received from the opposing device 103 has the SAR
The unit 2 assembles the AAL5 packet format (c). This data is sent to the data frame converter 5
And the payload portion is extracted. In the data of the payload part, the address part of the PPP, the control part, the flag (0x7E) and the FCS (frame check sequence)
Is added, the frame is assembled as an HDLC frame, and transmitted to the communication terminal 101 which is a PPP terminal via the terminal I / F unit 3. Thus, the ATM network 10
2 and a PPP terminal 101 and a VC-PPP terminal 103
Can realize data transmission in a transparent manner.

The HDLC described in each of the above embodiments
Terminals are HDL such as PPP, frame relay, SDLC
Shows all terminals that conform to the C format.

[0033]

According to the present invention, the data frame conversion of the data frame conversion unit enables the realization of the directly connected opposite communication via the ATM network with the opposite device having a different transmission format.

According to the present invention, there is provided an HDLC terminal,
Opponent communication with the opposing device of the ATM-LLC / SNAP system becomes possible.

Further, according to the present invention, opposing communication between the HDLC terminal and the opposing device of the ATM-VC multiplex system becomes possible.

According to the present invention, a PPP terminal, A
Opponent communication with the opposing device of the TM-PPP multiplexing system becomes possible.

As described above, by disposing the ATM transmission device of the present invention oppositely, the HDLC terminal can communicate with the opposite device via the ATM network, and the opposite device can communicate with various devices that perform the encapsulation of ATM. Direct connection communication can be realized.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an ATM data transmission device of the present invention.

FIG. 2 is a diagram for explaining frame / packet conversion according to the first embodiment;

FIG. 3 is a diagram for explaining frame / packet conversion according to the first embodiment;

FIG. 4 is a diagram for explaining frame / packet conversion according to the second embodiment;

FIG. 5 is a diagram for explaining frame / packet conversion according to the second embodiment;

FIG. 6 is a view for explaining frame / packet conversion according to the third embodiment;

FIG. 7 is a diagram for explaining frame / packet conversion according to the third embodiment;

FIG. 8 is a configuration diagram of a conventional ATM data transmission device.

[Explanation of symbols]

 Reference Signs List 1 central processing unit 2 SAR unit 3 terminal I / F unit 4 ATMi / f unit 5 data frame conversion unit 6 terminal I / F unit 101 communication terminal 102 ATM network 103 opposing device

Continuation of the front page (56) References JP-A-4-154339 (JP, A) JP-A-5-56066 (JP, A) JP-A-5-191431 (JP, A) JP-A-7-202895 (JP) JP-A-10-322399 (JP, A) JP-A-10-336200 (JP, A) JP-A-11-220472 (JP, A) JP-A-11-284640 (JP, A) 11-313085 (JP, a) Multiprotocol Enc apsulation over AT M Adaptation Layer 5, RFC1483, 7 May 1993 PPP over AAL5, RFC 2364, 7 May 1998 (58) investigated the field (Int.Cl. ^7, DB name ) H04L 12/56 H04L 29/10

Claims (2)

(57) [Claims] 1. An ATM transmission device connected to an ATM network, comprising: a terminal interface unit connected to a communication terminal;
An ATM interface unit for connecting to an M network, an SAR unit for disassembling and assembling ATM cells, and a data frame conversion unit for mutually converting between a data frame of the communication terminal and a data frame of an opposite device. The frame conversion unit is suitable for uplink data transmission.
Te is the information section and having a higher protocol has Ether Type
Part and control from HDLC frame composed by
Except for the part, information that has Ether Type
Take out the report section and attach the LLC / SNAP header
AAL5 packet payload with Ether Type
Information section that has been converted to data or has an upper protocol without Ether Type
From the HDLC frame configured as
Except for the control part, and there is no Ether Type,
Take out the information section that contains the
Adds a header and converts it to payload data of AAL5 packet without Ether Type , and at the time of downlink data transmission , deletes the header from the payload data of AAL5 with Ether Type and checks the address part, control part, flag and frame. to convert the HDLC frame consists of information part Ether Type there adds a sequence, or Ether Type no information unit pre an Ether Type in case of
Ether Type taken out from the storage means
By transmitting the Ether Type between the HDLC terminal as the terminal device and the opposite device of the ATM-LLC / SNAP system via the ATM network, An ATM transmission apparatus characterized in that data transmission can be made to a transparent material without causing any problems. 2. An ATM transmission apparatus connected to an ATM network, comprising: a terminal interface unit connected to a communication terminal;
An ATM interface unit for connecting to an M network, an SAR unit for disassembling and assembling ATM cells, and a data frame conversion unit for mutually converting a data frame of the communication terminal and a data frame of an opposite device, data frame conversion unit, when uplink data transmission, the address portion from the HDLC frame, except for the control unit extracts the <br/> information unit with or without Ether Type, without Ether Type the information unit VC
The AAL5 packet is converted to the payload data of the AAL5 packet which is a multiplex format, and the packet of the AAL5 packet without the Ether Type is transmitted at the time of downlink transmission.
Address data, control data, flags and checks
Adds a network sequence to the upper
No information section with protocol or Ether Type
By converting the HDLC frame consists is much protocol information unit, HD as the end-terminal device
An ATM transmission apparatus characterized in that data can be transmitted in a transparent manner between an LC terminal and an opposite apparatus of the ATM- VC multiplex system via the ATM network .