EP0455827A1
Expired / Lapsed
EP
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Changing over method for doubled atm switch system
Assignee: Fujitsu Ltd
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Filing: 1990-11-29
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Granted: —
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Expires: 2010-11-29
Abstract
Abstract A system changing over method for a cell exchange system, which has doubled asynchronous transfer mode (ATM) switches for exchanging ATM cells, and can change over the ATM switches correctly without the lack and duplication etc. of the cells. On the input sides of the ATM switches, bits which show being active for the switch of an active system and being stand-by for the switch of a stand-by system respectively are inserted into the headers of the cells sent from a transmission line respectively and are inputted to the ATM switches; on the output sides of the ATM switches, corresponding bits in the headers of the cells outputted from the respective switches of the doubled ATM switch are referred to, only cells which show being active are selected and are outputted to the transmission line. On the output sides of the respective ATM switches, buffers for storing the cells which show being active are provided respectively. When changing over the system, inputting cells into the previous active system is stopped and the cells which show being active are stored in the new active system. After all the cells which show being active in the previous active system are outputted, the cells which show being active stored in the buffer of the new active system are outputted.
Inventors
- 👤 Yumiko Kato
- 👤 Satoshi Kakuma
- 👤 Yasuhiro Aso
- 👤 Yoshihiro Uchida
- 👤 Hiroshi Miyake
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 21:17
CPC Classifications
H; H04; H04L; H04L49/00; H04L49/55; H04L49/552; H04L49/15; H04L49/30
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
113 words
In an exchange system in which an ATM switch is duplexed, a switching system in an ATM switch duplexed system characterized by: at the input side of the exchange system, inserting into the header of each of cells from a transmission line an AI bit indicating being active for an ATM switch in an active system or an AI bit indicating being on standby for an ATM switch in a standby system; and at the output side of the exchange system, referring to AI bits of the headers of cells output from the two ATM switches and selecting cells each having the AI bit indicating being active for transmission to a transmission line.
Claim 2
Dependent Claim
116 words
A switching system of an ATM switch duplexed system according to claim 1, characterized in that an input transmission line interface provided between the input side of the exchange system and the transmission line is provided with an AI bit inserter for inserting into the header of each of cells input from the transmission line the AI bit indicating being active for the active switch of the two ATM switches or the AI bit indicating being on standby for the standby switch and sending AI-bit inserted cells to corresponding respective switches; and an ACT controller connected to receive active/standby indicating signals from the two ATM switches for outputting AI-bit generation information to the AI bit inserter.
Claim 3
Dependent Claim
83 words
A switching system of an ATM switch duplexed system according to claim 2, characterized in that the said generation information output from the ACT controller instructs the said AI bit inserter to hold the previous state when the two ATM switches are both active or standing by and instructs the said AI bit inserter to generate an AI bit corresponding to the states of the two ATM switches when one of the two ATM switches is active and the other is standing by.
Claim 4
Dependent Claim
117 words
A switching system of an ATM switch duplexed system according to claim 1, characterized in that an output transmission line interface provided between the output of the exchange system and the transmission line is provided with two buffers for storing ATM cells output from the two ATM switches and having AI bits inserted indicating active; two buffer controllers for controlling inputting of cells to the two buffers and monitoring the presence or absence of data in the corresponding buffers; a selector for selecting either of outputs of the two buffers and outputting it to the transmission line; and a selector controller responsive to monitor outputs of the two buffer controllers for controlling cell output from the selector.
Claim 5
Dependent Claim
84 words
A switching system of an ATM switch duplexed system according to claim 4, characterized in that, at the time of outputting of cells from the selector to the transmission line, the selector controller controls the selector in such a way that it maintains the previous cell output state when the two buffers are both vacated or in the state in which data is present or it selects the buffer having data when one of the two buffers is vacated and the other has data.
Claim 6
Dependent Claim
114 words
A switching system of an ATM switch duplexed system according to claim 1, characterized in that there is provided an ACT mark assigner, at the input side of the ATM switch duplexed exchange system, for assigning to the header of a cell a bit indicating active for a switch in the active system and indicating standing by for a switch in the standby system for outputting to the ATM switches; two buffers, at the output side of the two ATM switches, for storing ATM cells output from the switches and assigned active indicating bits; and a selector for selecting either of the outputs of the two buffers and outputting it to the transmission line.
Claim 7
Dependent Claim
85 words
A switching system of an ATM switch duplexed system according to claim 6, characterized in that the selector, provided at the output side of the exchange system, at the time of selecting outputs of the two buffers, maintains the previous select state when the two ATM switches are both active or standing by and, when one of the two ATM switches is active and the other is standing by, selects the output of the buffer on the side of the ATM switch which is active.
Claim 8
Dependent Claim
120 words
A switching system of an ATM switch duplexed system according to claim 6, characterized by, in response to a system switching instruction from a central processing unit of the exchange system, switching by the ACT mark assigner the active/standby indicating bit assignment, stopping inputting cells to the ATM switch of the old active system, resetting the buffer at the output side of the ATM switch of the new active system, then storing only active indicating cells in the buffer and waiting for the buffer in the old active system to be vacated; and switching the selector when the buffer is vacated and resuming cell input to the ATM switch in the old active system to thereby complete the system switching.
Claim 9
Dependent Claim
55 words
A switching system of an ATM switch duplexed system according to claim 1 or 6, characterized by inserting into a vacated area of TAG information, for controlling the exchange of cells in the ATM switch, a 1 when being active or a 0 when standing by as the AI bit or the active/standby indicating bit.
Claim 10
Dependent Claim
128 words
In an exchange system in which an ATM switch is duplexed, a switching system in an ATM switch duplexed system characterized by comprising: two cell storage units, respectively provided at inputs side of two ATM switches, for storing input ATM cells; and system selector means, provided at the output side of the two ATM switches, for selecting either of the outputs of the two switches and outputting it to a transmission line, to thereby, at the time of switching between systems, stop outputting of cells from the two cell storage units to corresponding respective ATM switches to store input ATM cells into the cell storage units and cancel the stoppage of outputting of cells and switch the system selector means when residual cells disappear from the ATM switches.
References Cited (Backward Citations)
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