JP2837038B2 - Line handling part of packet switching equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a line switching unit of a packet switching apparatus.

[0002]

2. Description of the Related Art Conventionally, in a packet switching apparatus, a packet processing unit (PPU) has been
U) An N + m redundant configuration including several N and m spare packet processing units (PPUs) is employed.

FIG. 3 is a schematic block diagram of a conventional packet switching apparatus requiring a switchback.
(Zenichi Yashiro, Makoto Aoki, Mineo Nishiwaki, Takashi Honda: Large-capacity packet switching equipment, Proceedings of the Institute of Electrical Communication Research Conference, VO
L. 42, pp17-33, 1986 (2), see FIG. 9)

[0004] LCBU is a line controller for performing frame transmission / reception processing for a plurality of lines, and SEL is a line controller (L).
A selector for selecting a packet processing device (PPU) accommodating a CBU, and the PPU is a line control device (LCB).
U) a packet processing device that performs a packet exchange process on a packet received via U), a packet processing device group having a common backup packet processing device (PPU) for a plurality of packet processing devices (PPUs), HB
UF is a high-order buffer that performs interface processing to a connection link that connects between packet processing device groups (PPUG), SLCT is a connection link control unit between packet processing devices (PPU), TRM is a link termination circuit, and AMU is an entire packet switching device. Is a maintenance operation device that performs the maintenance operation process.

In FIG. 3 , an active packet processing device (PP) constituting a packet processing device group (PPUG)
U) Number N = 2, Number of spare packet processing units (PPUs) m =
This is the case of 1.

A line control unit (LCBU) terminates packet information from a line up to layer 2 and a packet processing unit (PPU) terminates layer 3 or more, and performs packet exchange by a coupling bus between the packet processing units (PPU). Do.

The switching operation will be described using data packet information as an example.

The packet information arriving from the line is terminated at Layer 2 by a line control unit (LCBU) and terminated at Layer 3 by a packet processing unit (PPU), and then sent to a target packet processing unit (PPU) by a coupling bus between the packet processing units (PPU). PP
U) and output to the line via the line control unit (LCBU).

In the conventional configuration, the packet processing device (PP
U) When a failure occurs, an operation of switching the selector of the line control device (LCBU) facing the packet processing device (PPU) to the backup packet processing device (PPU) is performed.

For example, when the packet processing unit (PPU) # 1 that has been performing packet communication has failed, the selector (SEL) of the opposite channel control unit (LCBU) is switched from the packet processing unit (PPU) # 1 to the backup packet processing. Equipment (PP
U) Switch to # 0.

However, as shown in FIG. 3 , the line control unit (LCBU) facing the packet processing unit (PPU) # 1 is a backup packet processing unit (PPU) other than the packet processing unit (PPU) # 1. The configuration is such that it can be switched only to # 0.

Similarly, when the opposite packet processing unit (PPU) fails, the other line control unit (LCBU) is switched only by the spare packet processing unit (PPU) # 0.

Therefore, the packet processing device (PPU) having a fault is switched to the spare packet processing device (PPU) # 0, and after replacing the faulty packet processing device (PPU), another packet processing device (PPU) becomes faulty. Even so, there arises a problem that the switching back to the backup packet processing unit (PPU) # 0 must be performed so that the switching can be performed.

[0014] When switching the packet processing unit (PPU), even if the program is pre-loaded on the backup packet processing unit (PPU), it takes time to download the subscriber information to the backup packet processing unit (PPU). As a result , the layer 2 and layer 3 links are disconnected, and the link is reset after switching to the spare packet processing unit (PPU).

In the meantime, the subscriber cannot communicate and the service is reduced.

As described above, in the conventional configuration, when the packet processing unit (PPU) is switched, switching back must be performed without fail, and there is a problem that a single failure causes a service degradation to the subscriber twice. .

[0017]

As described above, the conventional configuration requires switching back in the event of a packet processing unit (PPU) failure.
Once again, there was a problem that the service was degraded to the subscriber.

An object of the present invention is to alleviate the problems of the prior art and to provide a line switching unit of a packet switching apparatus having a redundant configuration that does not perform switchback.

[0019]

Accordingly, the structure of the present invention is as follows. That is, it has N lines (# 1 to #N) for transmitting packet information and N line termination units (3) for terminating the layer of the packet information.
To #N) and the line terminating unit (3) are connected in a one-to-one manner, and further m line terminating units (3) are installed in the line corresponding unit (2) of the packet switching apparatus (1). An arbitrary line (# 1 to #N) and an arbitrary line terminal (3, 6) are provided between the line (# 1 to #N) and the N + m number of the line terminal (3, 6). Can be connected in exactly the same way in any combination, and when a failure is detected at the line termination, the line termination
To the protection line terminating unit, and the switched faulty line
A packet switching device (1) is provided with a line switching mechanism (4) having a termination unit as a protection line termination unit .

Alternatively, it has N lines (# 1 to #N) for transmitting the packet information and N line terminating units (3) for terminating the layer of the packet information. #
N) and the line terminating unit (3) are connected one-to-one, and in the line corresponding unit (2) of the packet switching apparatus (1), p monitor line terminating units (7) are installed and the line (# 1
To #N) and a line switching mechanism (4) having a multi-connection function between the (N + p) line terminating units (3, 7). It has the configuration as (2).

[0021] The normal function of connecting line switching mechanism the line A
The line A can be changed to the line corresponding unit C by connecting the line corresponding unit B to the line corresponding unit B, while the multi-connection function means that the input signal from the line A It is connected to the output signal to the corresponding section C (in the second embodiment, the monitor line termination section).

[0022]

In the present invention, a line switching mechanism (4) for freely switching all the lines (# 1 to #N) is provided at a stage preceding the line terminating section (3), and the line switching mechanism (4) can be arbitrarily set. Perform control that can be connected.

According to the present invention, by providing the line switching mechanism (4) in front of the line terminating unit (3,6), when switching the line terminator to the spare line terminating unit (6), a fault After replacing the line terminating unit, the line terminating unit can operate as the protection line terminating unit (6).

[0024] In other words, characterized in that the switch-back of the line terminating unit is not required.

[0025]

Embodiments of the present invention will be described below with reference to the drawings.

FIG . 1 is a schematic block diagram of a line corresponding part of a packet switching device as a first embodiment of the present invention.

As shown in FIG. 1, the line handling unit 2 of the packet switching apparatus 1 of the present invention has N + m line termination units (N + m line termination units (3) and m protection line termination units 6). 3, 6) and a line switching mechanism 4.

The line terminating sections (3, 6) perform Layer 2 termination, and the line switching mechanism 4 performs N lines (# 1 to #N).
The operation of switching freely is performed.

The line switching mechanism 4 is connected to the lines (# 1 to #N)
It is needless to say that any means can be used for the time division switch, the space division switch, and other changeover switches as long as they can be switched freely.

The coupling mechanism 5 includes a line termination unit (3, 6).
This is a mechanism for coupling between the processors, and as long as communication between a plurality of processors can be performed, a standard bus such as a multibus or a coupling mechanism such as a LAN may be used.

The packet switching operation will be described using a data packet as an example.

The packet information arriving from the lines (# 1 to #N) is delivered to the line terminating units (3, 6) selected by the line switching mechanism 4 and terminated.

[0033] Then, after sent to the line terminating unit (3,6) for the purpose by the coupling mechanism 5 is output to the appropriate line by line switching mechanism 4.

Next, a description will be given of the switching operation when the line terminating unit (3,6) is hampered.

As an example, the line # 1 is a line termination unit # 1 (3)
And the line termination unit # 1 (3) becomes an obstacle.

When a failure in the line termination unit # 1 (3) is detected, the line switching mechanism 4 switches the line # 1 to the line termination unit # 1.
From (3), the connection is switched to one of the protection line termination units 6, and the protection line termination unit 6 whose connection has been switched is newly replaced with the line termination unit # 1.
Used as (3).

The line switching mechanism 4 includes all lines (# 1 to #N)
Can be switched freely, so the line terminator where the fault occurred #
After replacing 1 (3), it can be handled as the protection line termination unit 6.

FIG . 2 shows a second embodiment of the present invention for realizing a monitor function.
FIG. 3 is a schematic block diagram of a line corresponding unit of a packet switching device as an example of the embodiment.

If the line switching mechanism 4 has a multi-connection function, for example, p monitor line terminators 7 for monitoring packet information arriving from the lines (# 1 to #N) are installed, and 7 is connected to the line switching mechanism 4 in the same manner as the line terminating unit 3, so that packet information can be monitored while performing packet communication.

[0040] in the same manner as the line terminating unit 3 monitor the line terminating unit 7
It is needless to say that the connection position is also free.

[0041]

As described above, according to the line handling unit of the packet switching apparatus of the present invention, the line terminating unit can be switched to the backup line by providing the line switching mechanism that can freely switch the line before the line terminating unit. Even when switching to the terminating unit, the switched line terminating unit can be newly treated as a protection line terminating unit.

[0042] Thus, it caused the advantage of cutting back is not required.

[0043] Of course, it will be carried out similarly to the conventional link reconfiguration by switching the line terminating unit, during which the subscriber is undeniable that a service degradation can not communicate.

[0044] However, it only once degradation of service is the conventional two is a great advantage to the subscriber.

Since the line switching mechanism has a multi-connection function, a new function of monitoring packet information of an arbitrary line while performing packet communication and monitoring errors by installing a monitor line terminal is provided. There are advantages that are possible.

[Brief description of the drawings]

FIG. 1 is a schematic block configuration diagram of a line corresponding unit of a packet switching device as a first embodiment of the present invention.

FIG. 2 is a schematic block configuration diagram of a line corresponding unit of a packet switching device as a second embodiment of the present invention that realizes a monitor function;

FIG. 3 is a schematic block diagram of a packet switching device as a conventional example that requires switching back;

[Explanation of symbols]

LCBU line controller SEL selector PPU packet processing device PPUG packet processing device group HBUF high buffer SLCT PPU linkages link controller TRM link terminating circuit AMU maintenance operation device 1 packet switching device 2 line corresponding unit 3 line termination unit four line switching mechanism 5 Coupling mechanism 6 Protection line termination 7 Monitor line termination

 ──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Tadashi Usui Nippon Telegraph and Telephone Corporation, 1-6, Uchisaiwaicho, Chiyoda-ku, Tokyo (56) References JP-A-63-30054 (JP, A) 3-29336 (JP, B2) JP 55-18089 (JP, B2)

Claims (2)

(57) [Claims] 1. A communication system comprising: N lines for transmitting packet information; and N line termination units for terminating a layer of the packet information, wherein the line and the line termination unit are connected one to one. In the line handling unit of the packet switching apparatus, m line termination units are further installed, and a failure is detected in the line termination unit between the line and N + m line termination units.
Switch the line termination unit to the protection line termination unit.
A line switching unit for setting the failed line termination unit as a protection line termination unit. 2. A communication system comprising: N lines for transmitting packet information; and N line termination units for terminating a layer of the packet information, wherein the line and the line termination unit are connected one-to-one. A packet switching device, comprising: p monitor line terminators; and a line switching mechanism having a multi-connection function between the lines and N + p line terminators. Line-corresponding part of the switching equipment.