EP0281099A2
Expired / Lapsed
EP
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Method for managing logical channels for ISDN packet service
Assignee: Fujitsu Ltd
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Filing: 1988-03-02
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Granted: —
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Expires: 2008-03-02
Abstract
Abstract A method for management of logical channels essential for packet communication between an ISDN and subscribers. An ISDN cannot maintain details on each of the number of pieces of data terminal equipment in each subscriber. Therefore, the data terminal equipment returns to the ISDN the logical channel group number (LCGN) which has been allotted to itself upon receipt of a package at the ISDN. The ISDN then refers to the logical channel management memory corresponding to the specified data terminal equipment using that LCGN, while the data terminal equipment refers to the logical channel management memory in its own terminal adapter, with both thus obtaining the information required for the start of the packet communication. Further, when forming in the ISDN a logical channel management memory corresponding to a newly established data terminal equipment, direct registration is performed directly between the ISDN and data terminal equipment automatically for the LCGN, etc.
Inventors
- 👤 Yunoki Hideo
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-26 11:24
CPC Classifications
H; H04; H04Q; H04Q11/00; H04Q11/04; H04Q11/0428
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
114 words
A method for management of logical channels for packet service in an integrated services digital network (ISDN) used for packet communications, wherein each subscriber has a number of pieces of data terminal equipment and packets are handled, via a terminal adapter provided for each piece of data terminal equipment, with the ISDN, said method for management of logical channels for ISDN packet service characterized in that said ISDN is completely unaware of details of the said number of pieces of data terminal equipment in the above subscribers and said ISDN forms logical channel management memories of a number corresponding exactly to the subscribers so as to simplify the logical channel management by the ISDN.
Claim 2
Independent Claim
114 words
A method for management of logical channels for packet service in an integrated services digital network (ISDN) used for packet communications, wherein each subscriber has a number of pieces of data terminal equipment and packets are handled, via a terminal adapter provided for each piece of data terminal equipment, with the ISDN, said method for management of logical channels for ISDN packet service characterized in that said ISDN is completely unaware of details of the said number of pieces of data terminal equipment in the above subscribers and said ISDN forms logical channel management memories of a number corresponding exactly to the subscribers so as to simplify the logical channel management by the ISDN.
Claim 3
Dependent Claim
95 words
A method for management of logical channels according to claim 1, wherein a logical channel group number (LCGN) is allotted in the ISDN in advance for each of said pieces of data terminal equipment, thus enabling definition of the said available logical channels for each piece of data terminal equipment, and the ISDN side manages the state of the available logical channel numbers (LCN) and the attributes of the virtual circuits by the said logical channel management memories simply and for each LCGN, thus managing the virtual circuits for each piece of data terminal equipment.
Claim 4
Dependent Claim
57 words
A method for management of logical channels according to claim 2, wherein said terminal adapter is provided with means for returning and notifying to the ISDN said LCGN allotted in advance to said data terminal equipment during a call setup and said ISDN designates the logical channel used from the data terminal equipment side for packet communications.
Claim 5
Dependent Claim
47 words
A method for management of logical channels according to claim 3, wherein the said LCGN required at layer 3 of the packet communication is incorporated into the call offering procedure based on CCITT X.31 at layer 3 of the ISDN and returned and notified to said ISDN.
Claim 6
Dependent Claim
73 words
A method for management of logical channels according to claim 4, wherein a logical channel management memory is provided in the said terminal adapter at the said data terminal equipment side, said logical channel management memory including at least a first memory area which indicates whether or not said data terminal equipment can perform packet communication, packet communication being allowed to start only when said first memory area indicates packet communication is possible.
Claim 7
Dependent Claim
42 words
A method for management of logical channels according to claim 5, wherein the said first memory area indicates the number of idle virtual circuits and reduces the same by 1 each time a packet communication enable signal is sent to the ISDN.
Claim 8
Dependent Claim
39 words
A method for management of logical channels according to claim 6, wherein the timing at which the said number of idle virtual circuits is reduced by 1 is when a termination request (CN) packet is received from the ISDN.
Claim 9
Dependent Claim
68 words
A method for management of logical channels according to claim 5, wherein the said logical channel management memory of the data terminal equipment side has in addition to said first memory area a second memory area and third memory area, said second memory area registering the LCGN allocated to said data terminal equipment and said third memory area registering the virtual circuit attributes of said data terminal equipment.
Claim 10
Dependent Claim
89 words
A method for management of logical channels according to claim 2, wherein the said logical channel management memory of the ISDN side is provided therein with a busy/idle flag area which registers the state of logical channel numbers (LCN), in particular the state of use, and a memory area which registers the addresses corresponding to the LCN's being used, said addresses designating the working areas of the logical channel memories in the main memory unit, said working areas storing therein control information necessary for call processing of packet communications.
Claim 11
Dependent Claim
57 words
A method for management of logical channels according to claim 9, wherein when the ISDN newly designates an LCN necessary for packet communication, it selects one LCN flagged as idle among LCN's flagged as busy or idle in the busy/idle flag area and rewrites the bit in the busy/idle flag area corresponding to the LCN to busy.
Claim 12
Dependent Claim
78 words
A method for management of logical channels according to claim 1, wherein when a data terminal equipment is newly installed in a subscriber, information regarding the LCGN allotted to the newly installed data terminal equipment and the number of LCN's in the LCGN is notified to the ISDN and registered in the said logical channel management memory, in which case the registration can be performed directly with the ISDN by the data terminal equipment through the subscriber line.
Claim 13
Dependent Claim
52 words
A method for management of logical channels according to claim 11, wherein the direct registration in the ISDN is performed by transmission of a specific registration message and at least the LCGN, virtual circuit attributes, and available number of virtual circuits are written in the facility information element in the registration message.
Claim 14
Dependent Claim
31 words
A method for management of logical channels according to claim 2, wherein said data terminal equipment is a computerized terminal satisfying CCITT X.25 which can handle a plurality of virtual circuits.
Claim 15
Dependent Claim
30 words
A method for management of logical channels according to claim 2, wherein the virtual circuit management at the said ISDN side is performed in the packet handler in the ISDN.
References Cited (Backward Citations)
No citation records indexed.
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