JP3304068B2 - User network accommodating method and apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method and an apparatus for accommodating a user network such as a LAN in a wide area transfer network such as an ATM network, and more particularly to a method for distributing a shared band in a wide area transfer network. Things.

[0002]

2. Description of the Related Art Conventionally, a user network accommodating apparatus of this type includes a user network interface unit provided for each accommodating user network, and a band control unit. Transfer to a transfer network is known. Here, the user network interface unit is connected to a user network including a plurality of end user terminals. The band control unit is connected to a wide area transfer network, which is an ATM (Asynchronous Transfer Mode) network, by a VP (Virtual Path). A user frame in each user network is converted into an ATM cell in the user network interface unit, and a VC (Virtual Coding) set for each end user.
nnection), and the VCs are bundled by the band control unit to form a VP and transferred to the wide area transfer network.

Here, the band control unit has a plurality of queues for ATM cells in order to distribute the band, and has one scheduler for determining from which queue the ATM cells are read. The scheduler has one read slot, reads an ATM cell from a queue indicated by the slot, and transfers the ATM cell to the wide area transfer network.

[0004]

However, in the conventional user network accommodating apparatus, the bandwidth control can be performed only on a queue basis. For this reason, an end user group formed by grouping user networks and end users,
There is a problem that any one of the end users can be distributed as one unit, and only fairness can be maintained between the queues. For example, if the user network is a unit,
In this case, a queue is set for each user network. In this case, the bandwidth is fairly distributed between the user networks, but the fair bandwidth distribution is performed between the end user groups or the end users in the user network. There was a problem that was not.

To solve such a problem, it is conceivable to provide a plurality of the schedulers. For example, it is conceivable to provide a first scheduler for distributing bandwidth among a plurality of end users and a second schedule for distributing bandwidth between user networks. Here, the scheduler uses a queue corresponding to each read slot.

In this example, considering the case where the bandwidth distribution by the first scheduler is performed first, a user frame is first converted into an ATM cell and then input to a queue for each end user. Bands in between are fairly distributed. Thereafter, the data is input to the queue for each user network, and the second scheduler distributes the bandwidth between the user networks. Although the second scheduler fairly distributes the bandwidth between the user networks, there is a problem that fairness between end users cannot be maintained when a cell is discarded by the second scheduler.

On the other hand, considering the case where the bandwidth distribution by the second scheduler is performed first, the problem is that the fairness among end users cannot be maintained when the first queue is on a user network basis and cell loss occurs. There is.

[0008] However, the fairness here means that the bandwidth shared by a plurality of users is always distributed at a fixed ratio among the users regardless of the available bandwidth.
For example, when accommodating two user networks, a fixed ratio of 50%: 50% allows each user network to use at least 50% of the available bandwidth. 25%: 75%
It does not have to be equally divided as in

The present invention has been made in view of the above circumstances, and has as its object to group end user terminals in user networks as well as between user networks and to group end user terminals. It is an object of the present invention to provide a method and apparatus for accommodating a user network, which enables fair bandwidth distribution between end user groups.

[0010]

In order to achieve the above object, according to the present invention, a user frame from a user network is transmitted to an AT.
A user network interface means for converting to an M cell and transferring to the band control means using VC, and a band control unit for bundling the VCs from the user network interface means and accommodating them in a wide area transfer network; In a user network accommodating device accommodating one or more user networks including a user terminal, a source end user terminal of a user frame is identified, and a VC associated with the source end user terminal is transmitted from the user network interface using a VC associated with the source end user terminal. ATM cell transfer to the band control means is performed, and the band control means
A queue is provided for each VC group, and VCs are grouped into a hierarchical tree structure. A read slot corresponding to each VC group and indicating a VC group or a VC that is a child of the VC group is provided, and a root of the hierarchical tree structure is provided. The following procedure is repeated with the read slot corresponding to the VC group to be used as the parent read slot. A) Select the VC group or VC indicated by the parent read slot based on a predetermined rule. B) In the procedure a), select the VC group. If selected, the read slot corresponding to the VC group is set as a parent read slot, and the procedure a) is performed.
C) When a VC is selected in step a), an ATM cell is read from a queue provided in the VC and the ATM cell is transferred to a wide area transfer network.

According to the present invention, the user frame in the user network is converted into an ATM cell by the user network interface means, and the ATM cell is allocated to the VC associated with the source of the user frame and input to the bandwidth control unit. Is done. In the band control unit, ATM cells from the user network interface unit are input to queues provided for each VC. The ATM cells input to the queue are then read out according to the procedure and transferred to the wide area transfer network.

First, VCs are grouped in advance so as to form a hierarchical tree structure, and read slots corresponding to the respective VC groups are provided. Each read slot is set to indicate a VC group or VC that is a child of the corresponding VC group. When the read slot corresponding to the VC group that is the root of the hierarchical tree structure is set as the parent read slot, a VC group or VC indicated by the parent read slot is selected based on a predetermined rule, and the selection is a VC group selection. The selection based on the predetermined rule is repeated with the read slot corresponding to the VC group as the parent read slot, and if the selection is a VC selection, the selected VC is queued from the queue of the selected VC.
Read the TM cell.

[0013] As described above, VCs are grouped into a hierarchical tree structure, and read slots are provided corresponding to the respective VC groups. Can be distributed fairly. Therefore,
By associating a VC with a source of a user frame transferred by the VC on a per-end-user-terminal basis or a per-user-network basis, it is possible to appropriately accommodate units that require fair bandwidth distribution. Also, by changing the number of VC groups or VCs indicated in each read slot, the bandwidth distribution ratio can be adjusted as appropriate.

As an example of a preferred embodiment of the present invention, the user network has an end user group in which end user terminals are grouped, and the VC is set for each end user terminal. We propose a feature that is provided in correspondence with the end user group.

According to this, the shared bandwidth can be fairly distributed among the user networks, between the end user groups in the user network, and between the end user terminals in the end user group.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A user network accommodating apparatus according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a configuration diagram of a user network accommodating device and a user network, and FIG. 2 is an address-V referred to in a user network interface unit.
FIG. 3 is a diagram for explaining a C correspondence table, and FIG. 3 is a diagram for explaining the correspondence between queues and schedulers in the bandwidth control unit of FIG.
FIG. 4 is a diagram for explaining a hierarchical read slot of a scheduler.

The user network accommodating apparatus 1 accommodates a plurality of user networks 2a to 2c in one wide area transfer network 3. Here, the wide area transfer network 3 is an ATM (Asynchronous Trans
ferMode).

First, the configuration of the user networks 2a to 2c accommodated by the user network accommodation device 1 will be described. Each user network 2 includes a plurality of end user terminals 22, and each end user terminal 22 has an IP address. Also, a plurality of end user groups 21 in which a plurality of end user terminals 22 are grouped are set in each of the user networks 2a to 2c. In FIG. 1, the user network 2a includes end user terminals 22a, 22b, and 22.
c, and an end user group 2 including end user terminals 22d and 22e.
1b and an end user group 21c including end user terminals 22f and 22g.

Next, the configuration of the user network accommodation device 1 will be described. The user network accommodating apparatus 1 includes a plurality of user network interface units (hereinafter, referred to as "user network-IF units") 11a-1 corresponding to the accommodating user networks 2a-2c.
1c and one band control unit 12, which converts user frames of each user network 2 into ATM cells and transfers them to the wide area transfer network 3.

The user network-IF unit 11 accommodates one user network 2, and includes an address identification unit 111 and a VC.
A distribution unit 112 is provided, which converts a user frame from the user network 2 into an ATM cell and transfers the ATM cell to the band control unit 12 using a predetermined VC (Virtual Connection). That is, the user network-IF unit 11
As shown in the correspondence table of FIG. 2, the address of each end user terminal 22 of the accommodated user network 2 and the bandwidth control unit 12
A correspondence table with the VC used for transfer to the ATM cell is provided. The VCI to be used is determined from the address of the user frame identified by the address identification unit 111 using the correspondence table, and the VCI is added to the converted ATM cell. To the band control unit 12.

Here, the correspondence table includes an IP address of each end user terminal 22 and a V corresponding to each IP address.
It describes the CI. In the present embodiment, as shown in the correspondence table of FIG. 2, the end user terminals 22a to 22g
VC-a to VC-g for the IP addresses x1 to x7 of
Respectively.

The band control unit 12 controls each user network-IF unit 1
1 to form a VP (Virtual Path) and transfer ATM cells from each user network-IF unit 11 to the wide area transfer network 3.
Transfer to Specifically, the band control unit 12 has a queue 121 for ATM cells for each VC and a scheduler 122 for determining from which queue ATM cells are read. Further, as shown in FIG. 3, the band control unit 12 includes a database 123 in which VCs are grouped so as to form a hierarchical tree structure according to the configuration of the end user terminal 22. In the present embodiment, as shown in FIG. 1, the user network 2 has three layers of the user network 2, the end user group 21, and the end user terminal 22, so that the VC group (hereinafter referred to as "VCG") is also provided. 3
It has a hierarchical structure.

That is, the VCG (3) of the third hierarchy is a VCG which is the lowest hierarchy, and each VC is a control unit. In FIG. 3, VCG (n) -m_k is VCG (n-1)
Let it represent the k-th VCG included in −m. As shown in the figure, in the present embodiment, the end user group 21a and VCG (3) -1_1, the end user group 21b and VCG (3) -1_2, the end user group 21c and VCG (3) -1_3 respectively Yes, it is.

Here, the correspondence between the end user terminal 22 and the VC is the same as the correspondence table in FIG. Therefore, from the correspondence between the end user group 21 and the end user terminal 22, VCG (3) -1_1 is VC-a, VC-b, V
Vc (3) -1_2 is VC-d,
VC-e, and VCG (3) -1_3 is VC-e.
f, VC-g.

The second-layer VCG (2) is a VCG in which the third-layer VCG in which VCs are collected is a control unit.
It is. In the figure, VCG (n) -m is m in the n-th hierarchy.
The third VCG is shown. As shown in the figure, in the present embodiment, the user network 2a and VCG (2) -1, the user network 2b and VCG (2) -2, and the user network 2c and VCG (2)
-3 correspond. Here, the VCG (2) -1 corresponding to the user network 2a is, as described above, the end user groups 21a, 21b, 21c included in the user network 2a.
VCG (3) -1_1, VCG (3) -1_ corresponding to
2, VCG (3) -1_3.

The first layer VCG (1) is a VCG in which the second layer VCG, which is a VCG for each user network, is a control unit. That is, VCG (1) is VC
G (2) -1, VCG (2) -2, and VCG (2) -3.

The scheduler 122, based on the database 123 having such a hierarchical tree structure,
A hierarchical read slot used when reading an ATM cell from is set. The configuration of this read slot will be described with reference to FIG.

As shown in FIG. 4, this read slot S is a read slot S (1) of the first hierarchy, which is a VCG (2)-component of the VCG (1) of the first hierarchy.
1, VCG (2) -2, and VCG (2) -3. A second-layer read slot S (2) corresponding to each VCG specified here is set. Each second-layer read slot S (2) includes a slot in which a VCG that is a component of the corresponding second-layer VCG is specified. Similarly,
A third-level read slot S (3) corresponding to each VCG specified here is set. Since the third hierarchy is the lowest hierarchy, the third hierarchy has a slot specifying a VC which is a component of the VCG of the third hierarchy.

Next, an operation for transferring a user frame from each user network 2 to the wide area transfer network 3 will be described.

When the end user terminal 22 transmits a frame to the outside of the user network 2, first, the user network-IF unit 11 identifies the source address of the frame by the address identification unit 111, The VC distribution unit 112 refers to the correspondence table to determine a VC to be used for transfer. Specifically, the source end user terminal 22
Based on the IP address of the frame, the VC allocating unit 112 assigns the V
A VCI indicating C is added and transferred to the band control unit 12.
The ATM cells transferred to the band control unit 12 are input to a queue 121 provided in the VC.

Next, the band controller 12 reads out the ATM cells from each queue 121 and transfers them to the wide area transfer network 3 according to the following procedure. Scheduler 1 of bandwidth control unit 12
22 is a read slot S of all hierarchies,
The next slot after the slot referred to in the previous read is referred to. If the last referenced slot is the last slot, the first slot of the read slot is referenced. The details will be described below.

First, the reading slot S of the first hierarchy
Refer to (1). Here, the VCG is referred to by referring to the third slot of the read slot S (1) last time.
(2) It is assumed that the ATM is read from the VC queue included in -3. Read slot S (1) of the first hierarchy
Has three slots in total, so this time we will refer to the first slot.

Since the slot points to VCG (2) -1, next, the second-layer read slot S (2) -1 corresponding to the VCG is referred to. If the third slot of the read slot S (2) -1 has been referred to last time, the first slot is referred to this time.

Since the slot points to VCG (3) -1_1, next, the third-layer read slot S (3) -1_1 corresponding to the VCG is referred to. If the third slot of the read slot S (3) -1_1 was referred to last time, the first slot is referred to this time.

Since the slot indicates the VC-a, the queue 121a corresponding to the VC-a sends the ATM to the ATM.
Read the cell.

Here, when the queue 121a is empty, the read slot S (3) -1_1 of the third hierarchy is referred to again, the slot next to the slot used for referring to the queue 121a is referred to, and the VC is read. Queue 12 corresponding to -b
The cell is read from 1b.

As described above, when the queue to be read is empty, the queues are checked in the order of slots, and when a cell is input, the cell is read from the queue. Also,
As the slot, the slot used to determine the queue that has been finally read is set as the current reference slot.

If the third-layer read slot S
(3) If all VC queues indicated by -1_1 are empty, the process returns to the second-layer read slot S (2) -1, and
Referring to the slot next to the read slot S (2) -1, similarly, the read slot S (3) -1_ in the third hierarchy is referred to.
2 to determine the read queue.

Read slot S (2) -1 of the second hierarchy
If there is no queue in which a cell has been input even if all of the above are referred to, the process returns to the read slot S (1) of the first hierarchy, and the read queue is determined in the same manner.

When the queue 121 to be read is determined, the scheduler 122 deletes one ATM cell from the queue 121.
And transfers it to the wide area transfer network 3.

In this manner, the band between the user networks 2 is fairly distributed by the first-layer read slot S (1), and the band between the end user groups 21 in the user network 2 is the second-layer read slot S (1). The bandwidth is fairly distributed by S (2), and the band between the end user terminals 22 in the end user group 21 is the third level read slot S (3).
Will be distributed fairly. In addition, when the queue 121 is empty, by reading the cell from the queue in which the cell is input by referring to the next slot, it is expected that the band use efficiency will be improved.

Further, for example, when allocating twice the bandwidth to another user network 2b to the user network 2a, the first
If one slot indicating VCG (2) -1 indicating the user network 2a is added to the read slot S (1) of the hierarchy, the chance of reading cells from the user network 2a is doubled, thereby enabling use. The bandwidth is doubled. Similarly,
Regarding the allocation of the bandwidth between the end user terminals 22 and the end user groups 21, a slot indicating a corresponding VC or VCG is added to the read slot S (2) or S (3) of the second or third hierarchy. By doing so, the ratio of bandwidth distribution can be changed freely. Therefore, it is possible to change the ratio of the bandwidth distribution according to the user's contract or the like.

Next, a comparison with a conventional method of controlling fairness between end users with one scheduler having a non-hierarchical read slot will be described with reference to FIG. In the figure,
A, B, and C correspond to user networks, respectively, and Aa, Bb,
Cc corresponds to a queue provided for each end user. FIG. 5A shows a non-hierarchical structure corresponding to the read order of the hierarchical read slot 51 shown in FIG.
This is the conventional non-hierarchical read slot 52 of FIG.

When the queue Ac is empty when the scheduler tries to read from the queue Ac, FIG.
Is read from the queue Aa corresponding to the next slot when the hierarchical read slot 51 is used, but is read from the queue Bc when the non-hierarchical read slot 52 shown in FIG. 5B is used. Will be.

At this time, considering the upper-level user network, when the hierarchical read slot is used, the fairness among the user networks is maintained, but when the non-hierarchical read slot is used, Fairness between user networks is not maintained. Therefore, it can be seen that the present invention is effective for simultaneously maintaining fairness for each layer of the hierarchical user network.

In this embodiment, a VC is provided for each end user terminal. However, if necessary, a VC distribution unit is set such that end user terminals in one end user group use the same VC. You may. In this case, the fairness of the bandwidth distribution between the end user terminals cannot be maintained within the end user group, but the fairness of the bandwidth distribution can be maintained between the end user groups as described above. That is, it is possible to freely set the bandwidth distribution according to the usage form, the user's contract, and the like.

[0047]

As described in detail above, since VCs are grouped in a hierarchical tree structure and read slots are provided for each VC group, a common parent V
VCs having a C group or a parent VC between VC groups
Bands distributed to groups can be distributed fairly. Therefore, by associating a VC with a source of a user frame transferred by the VC on a per-end-user-terminal basis or on a per-user-network basis, it is possible to appropriately accommodate a unit requiring fair bandwidth distribution. Become. Also, by changing the number of VC groups or VCs indicated in each read slot, the bandwidth distribution ratio can be adjusted as appropriate.

When the user network has an end user group in which end user terminals are grouped, the VC is set for each end user terminal, and the VC group is made to correspond to the end user group. With this arrangement, the shared bandwidth can be fairly distributed among the user networks, between the end user groups in the user network, and between the end user terminals in the end user group.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a user network accommodation device and a user network.

FIG. 2 is a diagram for explaining an address-VC correspondence table referred to by a user network interface unit;

FIG. 3 is a view for explaining the correspondence between queues and schedulers in the bandwidth control unit of FIG. 1;

FIG. 4 is a diagram illustrating a hierarchical read slot of a scheduler.

FIG. 5 is a diagram illustrating a comparison with a conventional user accommodation device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... User network accommodation apparatus, 11 ... User network interface part, 111 ... Address identification part, 112 ... VC distribution part, 12 ... Band control part, 121 ... Queue, 122 ... Scheduler, 123 ... Database, 2 ... User network, 21
... End user group, 22 ... End user terminal, 3
… Wide area transfer network

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shunsuke Tsutsumi 3-9-1-2 Nishi-Shinjuku, Shinjuku-ku, Tokyo Nippon Telegraph and Telephone Corporation (72) Hiroyuki Hara 3--19, Nishi-Shinjuku, Shinjuku-ku, Tokyo No. 2 Within Nippon Telegraph and Telephone Corporation (56) References JP-A-9-149051 (JP, A) 1998 IEICE Communications Society Conference B-7-46, September 7, 1998 The Institute of Electronics, Information and Communication Engineers Technical Report IN 97-160, February 20, 1998 IEICE Technical Report SS E92-176, March 17, 1993, 001, CSNG 199900585019 (58) Fields surveyed (Int. Cl. ⁷ , (DB name) H04L 12/56 H04L 12/28

Claims (2)

(57) [Claims] 1. A user frame from a user network is sent to an ATM.
One or more end-users, comprising: a user network interface means for celling and transferring to a band control means using VC; and a band control unit for bundling VCs from the user network interface means and accommodating them in a wide area transfer network. In a user network accommodating device accommodating one or more user networks including a terminal, a source end user terminal of a user frame is identified, and a bandwidth is transmitted from the user network interface using a VC associated with the source end user terminal. The ATM cell transfer to the control means is performed. The bandwidth control means provides a queue for each VC and groups the VCs into a hierarchical tree structure.
A read slot corresponding to the C group and indicating a VC group or a VC that is a child of the VC group is provided, and the following procedure is repeated with the read slot corresponding to the VC group that is the root of the hierarchical tree structure as the parent read slot. B) selecting a VC group or VC indicated by the parent read slot based on a predetermined rule. B) If a VC group is selected in step a), the read slot corresponding to the VC group is set as a parent read slot. a) is performed. c) If a VC is selected in step a), the VC is selected.
ATM cells are read from the queue provided in the ATM.
A method for accommodating a user network, comprising transferring a cell to a wide area transfer network. 2. A user frame from a user network is transferred to an ATM.
One or more end-users, comprising: a user network interface means for celling and transferring to a band control means using VC; and a band control unit for bundling VCs from the user network interface means and accommodating them in a wide area transfer network. In a user network accommodating apparatus accommodating one or more user networks including a terminal, the user network interface means includes: source identification means for identifying a source end user terminal of a user frame;
VC distributing means for performing ATM cell transfer from the user network interface to the band control means using a VC associated with the source end user terminal, the band control means comprising: a queue provided for each VC;
Are grouped into a hierarchical tree structure, and a VC corresponding to each VC group and
A read slot for designating a VC group or VC that is a child of a group, and a transfer means for selecting a VC based on the database and the read slot, reading ATM cells from a queue of the selected VC, and transferring the ATM cells to a wide area transfer network. The VC is selected by the transfer unit based on a database and a read slot of the hierarchical tree structure, and a read slot corresponding to a VC group serving as a root of the hierarchical tree structure is set as a parent read slot based on a predetermined rule. A VC group or a VC indicated by the parent read slot is selected, and when the selection is a VC group selection, the selection based on the predetermined rule is repeated with the read slot corresponding to the VC group as the parent read slot. Characteristic user network accommodation device.