JPH10229400A - Method for setting virtual channel for atm subscriber line signal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently utilize a band, a VPI(virtual pass identifier), a VCI (virtual channel identifier) by a method for setting a VC(virtual channel) for a subscriber line signal in a line to connect an ATM exchange with an ATM line concentration device. SOLUTION: A VC for a subscriber line signal is set by informing a call preparation signal from a subscriber's terminal 3 to an ATM exchange 2 for every call by using a metasignaling. In this case, related to the ATM exchange 2, a VPI and a VCI is decided by retrieving empty VPI and VCI by a VPI/VCI empty and occupied state managing tables 21, 22 of the ATM exchange 2 and the ATM concentration device 1 of the VC for metasignaling signal, the VPI, the VCI and completion of setting them are informed to each other by using an M channel 5 for maintenance, the call preparation signal is set and released by using a C-plane 4 for transmitting and receiving the subscriber line signal, and communication is performed by using a U plane 7 for transferring user information.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an ATM switch and an ATM switch.
A virtual channel for a subscriber line signal (Virtual Channel, hereinafter, referred to as a line) connecting the TM concentrator.
With regard to a method of setting a VC (abbreviated as VC), in particular, setting of a VC for a subscriber line signal is performed for each call so that a virtual path identifier (Virtual Pass Identifier) is set.
r, hereinafter abbreviated as VPI), virtual channel identifier (Vir)
dual channel identifier (hereinafter abbreviated as VCI) and V that enables effective use of bandwidth.
Related to the C setting method.

[0002]

2. Description of the Related Art Conventionally, an ATM using a statistical multiplexing method has been known.
The network is composed of a switching system and a concentrator system, and each terminal is accommodated in an ATM concentrator or directly accommodated in an ATM exchange. On the other hand, a virtual channel (Virtual
As a method of setting l Channel (hereinafter abbreviated as VC), when a fixed VC is set between terminals, this VC is a PVC (Permanent Virt).
This VC is called an SVC (Switch Channel) and is used to set a VC between terminals when necessary.
This is called a “ched Virtual Channel”. When setting a signal VC for a C plane (control plane, Control) for transmitting / receiving a subscriber line signal in a line connecting the ATM concentrator and the ATM exchange,
It was done as follows. A VC for a subscriber line signal between the ATM exchange and the subscriber terminal is set by an instruction from the operation system. In this case, each subscriber terminal has a different virtual path between the ATM concentrator and the subscriber terminal. (Virtual Pass, hereinafter abbreviated as VP). On the other hand, VPI for subscriber line signal
And the VCI are in one-to-one correspondence between the ATM switch and the ATM concentrator and between the ATM concentrator and the subscriber terminal, and the VPI and VCI between the ATM switch and the ATM concentrator are fixedly determined in advance. . The ATM concentrator converts the VPI and VCI between the ATM concentrator and the subscriber terminal into the predetermined VPI and VCI between the ATM switch and the ATM concentrator as described above on a one-to-one basis. A VC for a subscriber line signal between the exchange and the ATM concentrator is set.

[0003]

However, in the conventional technique, the V for all the subscribers accommodated in the ATM concentrator is required.
Since it is necessary to secure PI and VCI in advance,
There has been a problem that VPI, VCI and bandwidth cannot be used effectively. Therefore, an object of the present invention is to solve such a conventional problem and to set the VPI and VCI for all the subscribers when setting the subscriber line signal VC in the line connecting the ATM switch and the ATM concentrator. It is an object of the present invention to provide a method of setting a virtual channel for an ATM subscriber line signal, which allows effective utilization of VPI, VCI and bandwidth without previously securing.

[0004]

In order to achieve the above object, in the method of setting a virtual channel for an ATM subscriber line signal according to the present invention, first, an operation system prepares a call from a subscriber terminal to an ATM exchange. An instruction to set a VC for the meta-signaling signal for notifying the signal to the ATM exchange is given, and then the VP of the VC for the meta-signaling signal is set.
I, VPI and VCI are determined based on the occupied / unoccupied state of the VCI, and then notified using the M channel for transmitting and receiving a maintenance signal from the ATM switch to the ATM concentrator, and then the VPI of the VC for the meta signaling signal , VCI, and the ATM concentrator, and between the ATM concentrator and the subscriber terminal. Then, the ATM switch is notified using the VC for meta-signaling signal, and then the ATM switch and the ATM concentrator are connected. The VPI and VCI used as the VC for the subscriber line signal are determined between the devices, and then the VPI and VC are determined.
I to the ATM concentrator, and then the ATM exchange and the AT
Correspondence is established between M concentrators and between ATM concentrators and subscriber terminals, and then the VC for subscriber line signals is released. As a result, the VPI / VCI of the subscriber line signal VC between the ATM exchange and the ATM concentrator can be set for each call, so that the VPI / VCI of the subscriber line signal VC can be set.
And effective use of bandwidth.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The principle of operation and embodiments of the present invention will be described below in detail with reference to the drawings. (Principle of Operation) In the present invention, the ATM exchange
Recognizing the VPI / VCI idle / busy state of the VC for the meta-signaling signal between the M exchange and the ATM concentrator, determines whether the VPI and VCI selected by the ATM exchange can be used by call admission control, VPI and VCI to be used are determined based on the determination result. V of meta signaling signal VC between ATM switch and ATM concentrator
A signal for notifying PI and VCI is defined, and a signal type, VPI, and VCI are set as information elements of the signal. With these signals, the ATM switch notifies the ATM concentrator of the VPI and VCI, thereby enabling the setting of the meta-signaling signal VC by the ATM switch. The VC for the subscriber line signal can be set by notifying the ATM exchange of a call preparation signal from the subscriber terminal by using the VC for the meta-signaling signal. More specifically, in the ATM exchange, the VP of the VC for the meta-signaling signal between the ATM exchange and the subscriber terminal.
In order to enable specification of I and VCI, it is necessary to determine in advance all the VPIs and VCIs used as the VCs for the meta-signaling signal, and to always recognize the latest idle / busy state of all the VPIs and VCIs. is there. ATM switch and AT
Define a signal for notifying the ATM concentrator from the ATM exchange of the VPI and VCI used for setting the VC for the meta-signaling signal between the M concentrators, and set the signal type, VPI, and VCI as information elements of the signal. I do. As other signals used for setting the VC for the meta-signaling signal,
When the setting of VPI and VCI is completed in the ATM concentrator, a signal for notifying the completion of the setting from the ATM concentrator to the ATM exchange is defined, and the signal type, V
Set PI and VCI.

[0006] Next, from the operation system to the ATM
A signal is transmitted to the exchange to notify the setting instruction of the VC for the meta-signaling signal. When the ATM exchange receives the signal notifying the setting instruction of the meta signaling signal VC, the ATM exchange has a meta signaling signal between the ATM exchange and the ATM concentrator for each of the ATM exchange and the ATM concentrator owned by the ATM exchange. Immediately reflect the change in the occupied state of each VPI and VCI of the service VC,
The VPI / VCI free / busy state management table storing the latest state is searched to find a free VPI / VCI. Then, the VPI and VCI are closed, and A
The VPI and VCI are set in the TM exchange, and the VP
A signal channel (M channel) that uses a signal defined for notifying I and VCI from the ATM switch to the ATM concentrator, sets a signal type and the VPI and VCI as information elements of the signal, and transmits and receives a maintenance signal. To the ATM concentrator to the ATM concentrator. The ATM concentrator receives the signal transmitted from the ATM exchange, and determines the A based on the signal type and VPI and VCI set in the information element.
VPI and VCI are set in the TM concentrator. And A
The signal type and VPI, V are used as signal information elements by using a signal defined for notifying the ATM switch from the TM concentrator to the ATM switch.
The CI is set, and the setting completion is transmitted by a signal channel (M channel) for transmitting and receiving the maintenance signal. The ATM exchange receives the setting completion signal, and thereby receives the ATM.
A meta signaling signal VC for transmitting and receiving a meta signaling signal between the exchange and the ATM concentrator is set. When the call preparation signal from the subscriber terminal is notified to the ATM exchange by meta-signaling using the VC for the meta-signaling signal, the ATM exchange exchanges the V for the subscriber line signal.
C is set, and at the end of the call, the subscriber line signal VC is released.

(Embodiment) FIG. 1 is a connection configuration diagram of an ATM switch, an ATM concentrator, an ATM subscriber terminal, and an operation system according to an embodiment of the present invention. In FIG. 1, 1 is an ATM concentrator, 2 is an ATM switch, and 3 is A
The TM subscriber terminal 4 transfers the call preparation signal between the ATM subscriber terminal 3 and the ATM exchange 2 by meta-signaling,
And a C plane for transferring a subscriber line signal between the ATM subscriber terminal 3 and the ATM exchange 2; 41, a VC for a meta-signaling signal between the ATM subscriber terminal 3 and the ATM exchange 2; 42, an ATM subscriber terminal 3 A VC 5 for a subscriber line signal between the ATM switch 2 and the ATM channel 2 is an M channel (M) for transferring a maintenance signal between the ATM switch 2 and the ATM concentrator 1.
6 is a BC for transferring a control signal between the ATM switch 2 and the ATM concentrator 1.
C channel (Bearer Connection C)
control, bearer connection control surface), 7 is AT
U-plane (User protocol) for transferring user information between the M subscriber terminal 3 and the ATM switch 2
Plane) and 8 are operation systems. FIG.
Shows a case where the VC for the meta-signaling signal of each ATM subscriber terminal 3 uses VPI = 3, VCI = 0, 1, 2.

FIG. 2 is a diagram for explaining an example of setting a VC for a subscriber line signal between an ATM exchange and an ATM concentrator according to an embodiment of the present invention. In FIG. 2, 1 is an ATM concentrator, 2 is an ATM switch, 21 is a VPI / VCI idle / busy state management table in a VC for a meta-signaling signal between the ATM switch and the ATM concentrator of the ATM switch provided inside the ATM switch, 22 Is a VPI / VCI idle / busy state management table for a VC for a meta-signaling signal between the ATM switch and the ATM switch provided in the ATM switch, 3 is an ATM subscriber terminal, 4 is a C plane, and 5 is an M channel. , 7 is a U plane, and 8 is an operation system. In addition, (31)-of FIG.
(45) shows the step numbers in parentheses in association with the processing steps in the next flowchart of FIG. In the example of FIG. 2, the ATM switch and the ATM concentrator V
The PI / VCI idle / busy state management tables 21 and 22 are
Both are “VPI = 0, VCI = 0 blocked, VPI = 0, V
CI = 1 blocked,... VPI = 3, VCI = 0 blocked, V
PI = 3, VCI = 1 blocked, VPI = 3, VCI = 2
Is empty.

FIG. 3 shows the ATM exchange and the AT in FIG.
6 is a flowchart for setting a subscriber line signal VC between M concentrators. While referring to the configuration of FIG.
The setting operation of the subscriber line signal VC between the exchange and the ATM concentrator will be described in detail with reference to the flow of FIG. First, the operation system 8 instructs the ATM exchange 2 to set a meta signaling signal VC (step 31). A
In the TM exchange 2, the VPI / VCI idle / busy state management table 21 in the VC for the meta-signaling signal between the ATM exchange and the ATM concentrator of the ATM exchange 2 held inside the ATM exchange 2, and the ATM exchange 2 holds the same. VPI in the VC for the meta-signaling signal between the ATM switch and the ATM concentrator of the ATM concentrator 1
The VCI idle / busy state management table 22 is searched (step 32). The search in step 32 shows that both tables 2
A free VPI / VCI is extracted from 1 and 22 (step 33). Here, VPI = 3, VCI =
Since 0 and 1 are closed, VPI = 3 and VCI = 2 are extracted as empty.

Next, extracted VPI = 3, VCI = 2
Determine whether the call can be used by the call admission control (step 34). If the determination result of step 34 is Y
In the case of es, that is, when it is usable, the VPI / VCI of the VC for the meta-signaling signal is extracted as the extraction result (V
PI = 3, VCI = 2) is determined (step 35).
At this time, the ATM exchange 2 uses the ATM exchange 2
ATM exchange A of ATM exchange 2 held inside
V in VC for meta-signaling signal between TM concentrators
“V” in the contents of the PI / VCI idle / busy state management table 22
PI = 3, VCI = 2 empty ”to“ VPI = 3, VCI
= 2 blocks ”. That is, the VPI / VCI idle / busy state management tables 21 and 22 of the ATM switch and the ATM concentrator in FIG. 2 both show “VPI = 0, VCI = 0”.
Block, VPI = 0, VCI = 1 Block,... VPI =
3, VCI = 0 blocked, VPI = 3, VCI = 1 blocked, V
PI = 3, VCI = 2 closed "(not shown).

The ATM exchange 2 notifies the ATM concentrator 1 of the VPI = 3 and VCI = 2 used by the meta signaling signal VC via the M channel (step 3).
6). The VC for the meta-signaling signal is provided between the ATM concentrator and the ATM subscriber terminal in accordance with the ITU-T Recommendation I.T. According to the provisions of H.361, VPI = 0.VCI = 1, but there are a plurality of VCs for meta signaling signals between the ATM switch and the ATM concentrator.
Are multiplexed, if VPI = 0 and VCI = 1, overlapping between subscriber terminals will occur. For this purpose, it is necessary to change the VPI and VCI of the VC for the meta-signaling signal between the ATM exchange and the ATM concentrator. In this embodiment, the ATM concentrator has VPI = 3 ·
Convert to VCI = 2. Next, A from the ATM concentrator 1
The setting completion is notified to the TM exchange 2 (step 37).
The setting of the VC for the meta-signaling signal is performed between the ATM exchange and the ATM concentrator (step 38).

Next, a call preparation signal from the subscriber terminal 3 is notified to the ATM exchange 2 using the meta-signaling signal VC set in step 38 (step 39). A
In the TM exchange 2, a VC for subscriber line signal between the ATM exchange recognized by the ATM exchange 2 and the ATM concentrator.
VPI and VCI to be used as the VC for the subscriber line signal between the ATM exchange and the ATM concentrator are determined based on the VPI and VCI idle / busy state (step 4).
0). VPI and VCI determined in step 40
Is notified from the ATM switch 2 to the ATM concentrator 1 (step 41). In the ATM concentrator 1, step 4
After setting the conversion of the VPI and VCI of the subscriber line signal VC based on the VPI and VCI notified in step 1, the ATM
The line concentrator 1 notifies the ATM switch 2 of the completion of the setting (step 42). The setting of the subscriber line signal VC is performed between the ATM exchange and the ATM concentrator (step 4).
3). In response to a call from the subscriber terminal 3, a communication state is established (step 44). At the end of the call, the ATM switch 2 releases the VC for the subscriber line signal (step 45). In addition,
In the setting operation of FIG. 2, ILM is used instead of meta-signaling.
I (Interium Local Management)
nt Interface) control (ATM Foru)
m, ATM User-Network Interf
ace Specification Version
(Defined in 3.1).

[0013]

As described above, according to the present invention,
VC for subscriber line signal between ATM exchange and ATM concentrator
Can be set for each call, so that the VPI / VCI and bandwidth of the subscriber line signal VC between the ATM exchange and the ATM concentrator can be used effectively.

[Brief description of the drawings]

FIG. 1 shows an ATM switch and an ATM showing an embodiment of the present invention.
FIG. 2 is a connection configuration diagram of a line concentrator, an ATM subscriber terminal, and an operation system.

FIG. 2 shows an ATM switch and an ATM according to an embodiment of the present invention.
FIG. 3 is an explanatory diagram for setting a VC for a subscriber line signal between concentrators.

FIG. 3 is a flowchart of a subscriber line signal VC setting operation between the ATM exchange and the ATM concentrator in FIG. 2;

[Explanation of symbols]

1 ATM concentrator, 2 ATM switch, 3 ATM subscriber terminal, 4 C plane, 5 M channel, 6 BC
C channel, 7: U plane, 21: A of ATM switch
VPI / VCI idle / busy state management table in VC for meta-signaling signal between TM exchange and ATM concentrator, 2
2 ... VPI / VCI idle / busy state management table in VC for meta signaling signal between ATM switch and ATM concentrator in ATM concentrator, 41 ... V for meta signaling signal
C, 42: VC for subscriber line signal, 8: Operation system.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Satoshi Shiraishi Nippon Telegraph and Telephone Corporation 3-19-2 Nishishinjuku, Shinjuku-ku, Tokyo

Claims (1)

[Claims] 1. A subscriber terminal, an ATM switch for terminating a signal connection from the subscriber terminal, and a virtual path located between the ATM switch and the subscriber terminal and different for each subscriber terminal. A virtual path identifier (hereinafter referred to as VPI) of the accommodated subscriber line signal virtual channel (hereinafter referred to as VC).
) And a virtual channel identifier (hereinafter, referred to as VCI), an ATM concentrator for converting the ATM terminal and an operation system for giving instructions to the ATM concentrator. Meanwhile, a method of setting a VC for a meta-signaling signal used for transmitting a call preparation signal from the subscriber terminal and setting a virtual channel for a subscriber line signal between the ATM exchange and the ATM concentrator. An instruction to set a VC for a meta-signaling signal between the ATM switch and the ATM concentrator in order to notify the ATM switch by a meta-signaling of a call preparation signal from the subscriber terminal from the operating system to the ATM switch; A first step of performing the following steps: The ATM switch and the ATM VC meta signaling signal that lifting
The VPI and VCI of the meta signaling signal VC are referred to by referring to the VPI / VCI idle / busy state management table of the concentrator.
And VCI of a VC for meta-signaling signal between the ATM exchange and the ATM concentrator based on the idle / busy state of the ATM
A third step of notifying the determined VPI and VCI using a signal channel for transmitting and receiving a maintenance signal from the ATM exchange to the ATM concentrator; and VPI and V notified
A fourth step of, based on the CI, associating the VPI and VCI of the meta signaling signal VC between the ATM switch and the ATM concentrator and between the ATM concentrator and the subscriber terminal; A fifth step of notifying the ATM exchange using a VC for the meta-signaling signal in which a call preparation signal has been set, and the ATM exchange recognizes the A which is recognized by the ATM exchange.
A sixth step of determining VPI and VCI to be used as the subscriber line signal VC based on the VPI and VCI of the subscriber line signal VC between the TM exchange and the ATM concentrator; A seventh step of notifying the VPI and VCI from the ATM switch to the ATM concentrator; the ATM concentrator transmits the notified VPI and VC
VPI and VC of the subscriber line signal VC based on
E. an eighth step of associating the ATM switch / ATM concentrator with the ATM concentrator / subscriber terminal; and, upon termination of the call, the ATM switch sets the subscriber line signal VC
And a ninth step of canceling the virtual channel. A method for setting a virtual channel for an ATM subscriber line signal.