EP0282198A2
Expired / Lapsed
EP
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Communications system and components and methods for use therein
Assignee: Nortel Networks Ltd
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Filing: 1988-02-23
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Granted: —
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Expires: 2008-02-23
Abstract
Abstract A communications system comprises a plurality or network of switching nodes (10,12,14,16,18,20,22) interconnected by transmission links, time division multiplexed signals (2ii,28) being transported between entry nodes (10) and egress nodes (22) as "transactions" comprising a header portion (F1-F2) and a message portion (F3-F4), which may comprise signalling. The header portion (F1-F2) comprises a sequence of node exist address (NEA) which occur in the order in which the nodes will be encountered as the signal traverses the network. In each node (10-20), the leading node exit address (NEA) determines the exit through which the signal will emerge from that node so as to reach the next node in the sequence. The entire sequence of node exit addresses (NEA) is generated by access apparatus (26) at the entry node (10), conveniently by accessing a routing database (46) by means of a unique address (DIA) of a destination interface (26A) connected to an exit of the egress node (22) to which an intended recipient is connected. The destination interface address (DIA) may conveniently be produced by accessing another look-up table (36) using the recipient's directory number (DIR.NUM).
Inventors
- 👤 John Brian Terry
- 👤 Richard Vickers
- 👤 Stephen William Trevitt
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-24 13:19
CPC Classifications
H; H04; H04L; H04L5/00; H04L5/22; H04Q; H04Q3/00; H04Q3/64; H04Q3/66; H04Q3/665; H04L45/00; H04L45/34
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
166 words
A communications system comprising a plurality of switching nodes (10,12,14,16,18,20,22) interconnected by transmission links, said system being suitable for transporting between a first node (10) and a second node (22) signals (2ii,28) each comprising a message portion (F3-F4) and a header portion (F1-F2), said header portion (F1-F2) being determined before said signal is switched by said first node (10) and characterized by a set of node exit addresses (NEA), said addresses occurring in said header portion (F1-F2) in the same sequence in which said nodes will be encountered by said message portion (F3-F4) in passing between said first node (10) and said second node (22), at least said first node (10) and each node (14,18,20) intermediate said first node (10) and said second node (22) including detector means (128) for detecting in said header portion (F1-F2) a particular node exit address (NEA) and determining therefrom the exit whereby at least said message portion (F3-F4) should leave such node to reach the next node in said sequence.
Claim 2
Dependent Claim
166 words
A communications system comprising a plurality of switching nodes (10,12,14,16,18,20,22) interconnected by transmission links, said system being suitable for transporting between a first node (10) and a second node (22) signals (2ii,28) each comprising a message portion (F3-F4) and a header portion (F1-F2), said header portion (F1-F2) being determined before said signal is switched by said first node (10) and characterized by a set of node exit addresses (NEA), said addresses occurring in said header portion (F1-F2) in the same sequence in which said nodes will be encountered by said message portion (F3-F4) in passing between said first node (10) and said second node (22), at least said first node (10) and each node (14,18,20) intermediate said first node (10) and said second node (22) including detector means (128) for detecting in said header portion (F1-F2) a particular node exit address (NEA) and determining therefrom the exit whereby at least said message portion (F3-F4) should leave such node to reach the next node in said sequence.
Claim 3
Dependent Claim
33 words
A system as defined in claim 1, further comprising access means (26), associated with said first node (10), for accessing a routing database (46) to obtain said set of node exit addresses (NEA).
Claim 4
Dependent Claim
63 words
A system as defined in claim 2, wherein said access means (26) includes signalling means (38,42) for deriving from a destination interface address (RDIA), an address (DIA) of a destination interface (26A) associated with an exit of said second node (22) and means (38,44) for deriving said set of node exit addresses (NEA) to route the transaction signal to such destination interface (26A).
Claim 5
Dependent Claim
42 words
A system as defined in claim 3, wherein said means (38,44) for deriving said set of node exit addresses (NEA) serves to access a look-up table (46), using said destination interface address (DIA), to determine said set of node exit addresses (NEA).
Claim 6
Dependent Claim
46 words
A system as defined in claim 4, wherein said look-up table (46) comprises a group of sets of node exit addresses (NEA), said group being peculiar to that first node (10) and each set corresponding to a different route to a final node (22) accessible therefrom.
Claim 7
Dependent Claim
50 words
A system as defined in claim 2, in which said access means further includes means (44) for deriving said set of node exit addresses (NEA), in its entirety, in dependence upon a destination interface address (DIA) of a destination interface (26A) connected to an exit of said second node (22).
Claim 8
Dependent Claim
39 words
A system as defined in claim 6, in which said access means further includes means (38) for generating said destination interface address (DIA) in dependence upon a destination number (DIR.NUM) of a recipient associated with such destination interface (26A).
Claim 9
Dependent Claim
60 words
A system as defined in claim 7, in which said means (38) for generating said destination interface address (DIA) serves to do so by accessing a network database (36), said access means (26) further comprising means (44) for responding to said destination interface address (DIA) to access a routing database (46) and provide said set of node exit addresses (NEA).
Claim 10
Dependent Claim
97 words
A system as defined in claim 1 further comprising a switch means (128) including detector means (154,158) for detecting in said header a particular node exit address (NEA) and determining therefrom the exit whereby at least said message portion should leave such node to reach the next node in said sequence said switchmeans (128) further including means (150) for allocating said header to a channel in said exit, the arrangement being such that once a channel has been allocated, the remainder of the transaction signal may be routed to it without incurring significant store and forward delay.
Claim 11
Dependent Claim
124 words
A system as defined in claim 1, in which both said first node (10) and said second node (22) having access means (26) and destination interface means (26A), said access means (26) of said first node (10) serving to access a routing database (46) using a unique address (DIA) of the destination interface means (26A) of said second node (22), and vice versa, to obtain said set of node exit addresses (NEA), said access means (26) serving further to add an identifier (Figure 15(1)) to an outgoing transaction signal (2ii) and start a timer (54), and the destination interface means (26A) associated with the same node serving to detect a corresponding identifier (Figure 15(2)) in an incoming transaction signal and stop said timer (54).
Claim 12
Dependent Claim
81 words
A system as defined in claim 1 further comprising access means (26), associated with said first node (10), for adding to a transaction signal (2ii) entering the first node (10) an identifier (F2-F3) relating it to a particular call, and yet further comprising destination interface means (26A) associated with said second node (22) for detecting such an identifier in a transaction signal (2ii) received from said second node (22) and relating such received transaction signal (2ii) with a particular recipient (32).
Claim 13
Dependent Claim
52 words
A system as defined in claim 1, wherein said first and said intermediate nodes (10,14,18,20) are each adapted to transmit to said exit only said message portion (F3-F4) and such portion of the header portion (F1-F2) as remains after removal of its own one of said set of node exit addresses (NEA).
Claim 14
Dependent Claim
78 words
A system as defined in claim 1 further comprising access means (26), associated with said first node (10), for adding to a transaction signal (2ii) entering the first node an identifier (F2-F3) relating it to a particular call, and yet further comprising destination interface means (26A) associated with said second node (22) for detecting such an identifier (F2-F3) in a transaction signal received from said second node (22) and relating such received transaction signal with a particular recipient.
Claim 15
Independent Claim
176 words
A method of operating a communications system comprising a plurality of switching nodes (10,12,14,16,18,20, 22) interconnected by transmission links, said method comprising transporting between a first node (10) and a second node (22) transaction signals (2ii,28) each comprising a message portion (F3-F4) that may be continuous and of a duration determined by a user, and a header portion (F1-F2), said header portion (F1-F2) being determined before the transaction signals are switched by said first node (10) and comprising a set of node exit addresses (NEA) corresponding to the sequence in which at least said message portion (F3-F4) is to tranverse said switch nodes (14,18,20) in passing between said first node (10) and said second node (22), said method further comprising the steps of detecting (128) at least at said first node (10) and each node (14,18,20) intermediate said first node (10) and said second node (22), a particular node exit address (NEA) and determining therefrom the exit whereby at least said message portion (F3-F4) should leave such node to reach the next node in said sequence.
Claim 16
Independent Claim
176 words
A method of operating a communications system comprising a plurality of switching nodes (10,12,14,16,18,20, 22) interconnected by transmission links, said method comprising transporting between a first node (10) and a second node (22) transaction signals (2ii,28) each comprising a message portion (F3-F4) that may be continuous and of a duration determined by a user, and a header portion (F1-F2), said header portion (F1-F2) being determined before the transaction signals are switched by said first node (10) and comprising a set of node exit addresses (NEA) corresponding to the sequence in which at least said message portion (F3-F4) is to tranverse said switch nodes (14,18,20) in passing between said first node (10) and said second node (22), said method further comprising the steps of detecting (128) at least at said first node (10) and each node (14,18,20) intermediate said first node (10) and said second node (22), a particular node exit address (NEA) and determining therefrom the exit whereby at least said message portion (F3-F4) should leave such node to reach the next node in said sequence.
Claim 17
Dependent Claim
53 words
A method as defined in claim 14, further comprising the step of accessing a routing database (46), using an address (DIA) of a destination interface (26A) connected to an exit of said second node (22), to obtain said set of node exit addresses (NEA), in its entirety, for combining with said message portion.
References Cited (Backward Citations)
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