GB2403632A

GB2403632A - Coupling non-IP devices to an IP network for remote network management

Info

Publication number: GB2403632A
Application number: GB0315230A
Authority: GB
Inventors: Benny Christensen; Soren Sorensen
Original assignee: Motorola Inc
Current assignee: Motorola Solutions Inc
Priority date: 2003-06-30
Filing date: 2003-06-30
Publication date: 2005-01-05
Anticipated expiration: 2023-06-30
Also published as: GB2403632B; GB0315230D0

Abstract

The invention is concerned with incorporating non-IP (Internet Protocol) devices within an IP fault management system. Such devices typically denote equipment faults using relay switches and in the present invention the relays are connected to the port of an IP-enabled switch e.g. an Ethernet switch, hub or router. In the case of a relay that needs to inform the network of various device states including error conditions, the relay is arranged to control a virtual LAN circuit 110-120 of the port. During an error condition, the relay either provides a short circuit 130 (fig 1) or open loop circuit 230 (fig 2) causing the IP switch to report this fault to a fault management system by sending an SNMP (Simple Network Management Protocol) trap. In the case of the network needing to control the relays of devices, outputs of the IP switch port are arranged to provide a control voltage to the relay (fig. 3).

Description

Apparatus and method for coupling devices to a network

Technical Field

The invention relates to apparatus and method for coupling devices to a network, in particular, it relates to coupling non-protocol enabled devices to an protocol-based network.

_ckground In both wireless and wireline communication systems, there is a requirement to transfer data between communications units. Such data transfer needs to be effectively and efficiently achieved, in order to optimally use limited communication resources.

For data to be transferred across communication networks, a communication unit addressing protocol is required. ' ' Typically communication units are allocated addresses that.' are read by a communication gateway or router, which determines how to transfer the data to the addressed destination communication unit. This interconnection À between networks is generally known as internetworkirlg (or,...

the interned). , : Networks are often divided into sub-networks via gateways, with protocols defining a set of rules that allow an orderly exchange of information. The most popular protocol currently used to transfer data in communications systems is the Internet Protocol (IP).

IP corresponds to data transfer in the network layer (layer 3) of the well-known 7-layer open systems interconnection (OSI) model. Its operation is transparent to the physical and data link layers (1 and 2) and can thus be used on any of the standard cabling networks such as Ethernet, FDDI or token ring.

The Internet Protocol adds a data header onto the information passed from the transport layer. The resultant data packet is known as an Internet datagram. The header of the datagram contai ns information such as destination and source IP addresses, the version number of the IP protocol etc. An IP address is assigned to each node on the Internet. It is used to identify the location of the network and any sub-networks.

Occasionally, a node or sub-network is unavailable for routing or receipt of datagrams, typically due to an equipment fault or a scheduled maintenance. In such instances, a mechanism is required to alert the Network. In IP-enabled equipment, Simple Network Management Protocol:''''' (SNMP) alerts or 'traps' are used for such fault management. , , However, some equipment may exist in the system that does, '., not support remote network rnar-iagement ( for example, via SNMP) . Such devices typically denote equipment faults using relay switches.

Consequently some equipment upon which the IP based network relies is not capable of properly informing the network in the event of a fault.

The inventors have appreciated that it is desirable for such devices to be incorporated within the IP fault management system.

By the same token, it is not possible for the IP network to alter the states of relays within non-If enabled devices in order to configure said device as conditions or

requirements change. In the prior art (e.g.

htCp://www.rnoscad.com), separate control units or 'SCADA' units are required to interface with such devices, providing input/output ports to interface with such devices. Such units add expense and complication to the network.

More generally, these problems will occur between any protocol-based network and non-protocol enabled devices.

The purpose of the present invention is to address the above problems.

Summary of the Invention. '' '

_ _ _

In summary, the present invention operably couples non-If enabled devices to a protocol-based network by connecting ' the electronic switching means (for example, relays) that À either represent or control the states of such devices, to....

a port of a protocol-enabled switching means such as an Ethernet switch, a hub or a router.

In the case of relays that need to inform the network of various states (a transmission function), the relay is arranged to control a virtual-LAN circuit from the port. In the case of the network needing to control the relays (a reception function), outputs of the port are arranged to provide a control voltage to the relay.

In a first aspect, the present invention provides apparatus for operably coupling an output of a non-protocol enabled device to a protocol-based network, as claimed in claim 1.

In a second aspect, the present invention provides apparatus for operably coupling an input of a non-protocol enabled device to a protocol-based network, as claimed in claim 4.

In a third aspect, the present invention provides a method of operably coupling an output of a non-protocol enabled device to an protocol-based network, as claimed in claim 11.

In a fourth aspect, the present invention provides a method of operably coupling an input of a non-protocol enabled device to a protocol-based network, as claimed in claim 14.

Further features of the present invention are as claimed in À.

the dependent claims.

Embodiments of the present invention will now be described À.

by way of example with reference to the accompanying....

drawings, in which: ,

rief description of the drawings

FIG. 1 is a diagram of a closed loop between transmission and reception parts of an Ethernet port connection, incorporating an open relay in accordance with an embodiment of the present invention.

FIG. 2 is a diagram of a closed loop between transmission and reception parts of an Ethernet port connection, incorporating a closed relay in accordance with an embodiment of the present invention.

FIG. 3 is a diagram of transmission parts of an Ethernet port connection connected to a rel ay actuator in accordance with an embodiment of the present invention.

FIG. 4 is a diagram of a device control scenario j uxtaposing a prior art solution with an embodiment of the present invention.

FIG. 5 is a schematic diagram of a network comprising a network switching means with a port in accordance with an embodiment of the present invention.

Detailed description

Referring to FIG. 5, typically all IP networks 510 contain a IP-enabled switching means such as Ethernet switches 520, ''''' hubs or routers. The inventors of the present invention have appreciated that it is possible to expl oft one or more of the ports 530 on such IP-enabled switching means as (for example Ethernet switch 520). These ports 530 can be used... .

to receive information from, or change the states of, non IP-enabled equipment that signifies or alters states by '' '' activating or deactivating electronic switching means (for example a relay contact) . Such electronic switching means are shown in FIGs 1 to 3 respectively as relays 130, 230, 330.

In a first embodiment of the present invention, the arrangement of F. thernet port 530 and relay 130, 230 enables an output of a non-If enabled device, signified by activating or deactivating a relay contact, to be operably coupled to the IP network 510.

A typical use might be service/fault report management within a remote network management system for equipment that signifies faults by activating or deactivating a relay contact.

In the first embodiment of the present invention, a port 530 on an Ethernet switch 520 is used to convert a relay contact state 130, 230 into an SNMP trap as follows: Firstly, a virtual local area network (V-LAN) is assigned to one of the ports of the Ethernet switch 520.

Secondly, the transmission (Tx) part of the Ethernet port is looped back to the reception (Rx) part 120 of the À port. In operation, this allows an Ethernet idle pattern A!! generated by the switch 520 to flow between the Tx and Rx parts. Such a flow indicates normal operation of the V-LAN to the Ethernet switch 520. ..: As part of the Tx-Rx loop, the relay 130, 230 used by the non-If enabled equipment to signal an output is À' ' incorporated according to the type of reporting method used; Relay 130 closes to signal an output; or Relay 230 opens to signal an output, Where the output thus typically indicates a change from a default or common state.

Referring to Figure 1, in the case of the relay 130 closing to signal an output, then the relay]30 is arranged so that on error the relay 130 shorts the dual channels comprising the Tx-Rx (110-120) loop.

Referring to Figure 2, in the case of the relay 230 opening to signal an output, then the relay 230 is arranged so that on error the relay breaks the Tx-Rx (110-120) loop connection.

The result in each case is that the Ethernet idle pattern is not received by the Rx 120 part of the port.

Consequently the IP-enabled Ethernet switch 520 perceives the loss of reception as a failure of the virtual local area network. The Ethernet switch 520 will then report this fault to a fault management system by sending an SNMP trap.

It will be appreciated by a person skilled in the art that in addition to Ethernet switches per se, Hubs and routers À ,, also comprise switchable addressable ports that can be.. ,, similarly exploited, and this is envisaged within the scope of the invention.

In a second embodiment of the present invention, the, arrangement of Ethernet port 530 and relay 330 enables ''' control of state configurations for equipment that can alter some or all states by activating or deactivating relay contacts.

In the second embodiment of the present invention, referring to FIG. 3, the contacts of relay actuator 350 are connected to the Tx pins 110 of the Ethernet port 530.

The relay is then controlled by sending commands to enable or disable the port 530. This will enable or disable the Ethernet idle pattern AC signal sent over the Tx pins of the port, which is smooth-rectified to DC by rectification means 340 - typically a rectifying diode and RC circuit.

Thus when the port 530 is enabled, the Ethernet idle pattern is sent and the relay switches 'On'. When the port is disabled, the Ethernet idle pattern is replaced by a zero voltage and the relay switches 'Off'.

FIG. 4 illustrates a scenario wherein a critical system (for example, a bunked network communication system - see htCp://www. motorola.com/publicsafety/40-20-30-10.shtml) has two remote sites each including an active base site and a redundant site. A first remote site 910 comprises an active base site 420 and a redundant base site 430, and an arrangement for switching from the primary to redundant bases. A second remote site 450 also comprises an active À , base site 460 and a redundant base site 470, and an.... :.

arrangement for switching from the primary to redundant bases.

A prior art arrangement is illustrated for first remote,, site 410, and an embodiment of the present invention for ''' second remote site 450.

In each case, the central site 401 has SNMP connectivity to the remote site via two X.21 links 412, 452. In each case the X.21 links connect to two IP routers; for the first remote site routers 414 and 416, and for the second remote site routers 454 and 456.

The prior art arrangement depicted in the first remote site 410 requires use of a supervisory control and data acquisition (SCADA) unit 418. As the default, base site 1 420 is activated by enabling port 1 421 of SCADA 418 and base site 2 430 is deactivated by disabling port 2 431 of SCADA 418.

If base site 1 420 fails, the network manager on the central site 401 disables base site 1 420 by sending a command (Disable port - 1) to the SCADA 418 and enables base site 2 430 by sending a command (enable port 2) to the SCADA 418.

The embodiment of the present invention depicted in the second remote site 450 does not require a supervisory control and data acquisition unit. Instead, as the default, base site 1 460 is activated by enabling a port 461 on router 1 452, and base site 2 430 is deactivated by À , disabling a port 471 on router 2 454. 2:.

If base site 1 460 fails, the network manager on the: central site 401 disables base site 1 460 by sending an ' ' SNMP command (Disable port) to router 1 452, and enables, base site 2 470 by sending a command (enable port) to ''' router 2 454.

Consequently an arrangement utilizing the present invention does not need additional control units or non-If protocol commands to implement control of the base sites.

In an enhanced embodiment of the present invention, the numbers of ports connected to non-If equipped devices can be related to an equipment list, such that an operator can receive a clear indication of the state of the system.

In a further enhanced embodiment of the present invention, the numbers of such ports can be related to specific device state types in accordance with the nature of the information conveyed by the input or output relay.

In a still further enhanced embodiment of the present invention, software, either operating upon the Ethernet switch or elsewhere on the network is operable to interpret or transform the messages sent to or from such ports or the Ethernet switch according to the device type and/or device state type.

It will be clear to a person skilled in the art that alternative electrical switching means 130, 230, 330 may be used, such as transistor or valve based switching. " '"

lt will also be appreciated by a person skilled in the art 2...:.

that in addition to Ethernet switches, Hubs and routers also comprise switchable addressable ports that can be '2' similarly exploited, and this is envisaged within the scope À,2 of the invention, for example as illustrated in figure 4. ''

It will also be clear to a person skilled in the art that À switchable ports based on other network protocols are envisaged as applicable for connection to non-protocol enabled devices, for the purposes of the present invention.

Claims

Claims 1. Apparatus for operably coupling an output of a non - protocol

enabled device to a protocol-based network, comprising; a protocol-enabled switching means comprising at least a first port; a non- protocol enabled device operable to signify at least two device states by control of an electrical switching means, characterized by; a virtual local area network (V-LAN) assigned to a port of the protocol-enabled switching means; a pair of closed loops connecting two corresponding ' transmission and reception parts of said port; and I the electrical switching means operably coupled to either one or troth closed loops.
2. Apparatus according to claim 1 wherein in a case where,, , the electrical switching means is by default and/or in ' normal operation open; a connection from each closed loop to the electrical switching means of the non-protocol enabled device, such that closing of the electrical switching means creates a short circuit between the closed loops, and such that in operation a network signal being transmitted through the port is interrupted, causing a protocol-based report by the protocol-enabled switching means.
3. Apparatus according to claim 1 wherein in a case where the electrical switching means is by default and/or in normal operation closed; the electrical switching means operably coupled along one of the closed loop paths such that opening of the electrical switching means breaks the loop, and such that in operation a network signal being transmitted through the port is interrupted, causing a protocol-based report by the protocolenabled switching means.
4. Apparatus for operably coupling an input of a non protocol enabled device to an protocol-based network, comprising; a protocol-enabled switching means comprising at least a first port; a non-protocol enabled device operable to alter,, between at least two device states by control of an, :.

electrical switching means, characterized by; ':' a pair of closed loops connecting two corresponding,, transmission and reception parts of said port; and activation means of the electrical switching means ' ' operably coupled to both closed loops.
5. Apparatus according to claim 4 further cl-aracterised by; smoothed rectification means operable to generate a DC output from a network signal output by the port; activation means of the electrical switching means operably coupled to said smoothed rectification means, and such that upon a protocol-based command to enable the port, the electrical switch means is activated, and upon a protocol-based command to disable the port, the electrical switching means is deactivated.
6. Apparatus according to any one of the preceding claims wherein a storage means contains information associating non-protocol enabled devices and/or their state types with their corresponding port numbers on the network.
7. Apparatus according to claim 6 wherein software located upon the network is operable to, in the case of output from a non-protocol enabled device, interpret differently the protocol based message generated by the protocol-enabled switching means, according to the type of device and/or output state types associated with the port number.
8. Apparatus according to claim 6 or 7 wherein software À, located upon the network is operable to, in the case of ' :.

input to a non-protocol enabled device, interpret differently protocolbased commands from the network, according to the type of device and/or input state types '.: associated with the port number. , "
9. Apparatus according to any one of the preceding claims wherein the protocol-based report generated by the protocol-enabled switching means is an SNMP trap.
10. Apparatus according to claim 4, wherein File non- protocol enabled device is a site controller for remote base sites of a bunked communication system.
11. A method of operably coupling an output of a non protocol enabled device to a protocol-based network, the network comprising a protocolenabled switching means, said protocol-enabled switching means comprising at least a first port; and the device comprising an electrical switching means operable to signify at least two device states, the method characterized by; assigning a virtual local area network (V-LAN) to a port of the IP-enabled switching means; connecting two corresponding transmission and reception halves of said port to form a pair of closed loops; and operably coupling the electrical switching means to lO one or both closed loops.
12. A method according to claim ll, wherein in a case where the electrical switching means is by default and/or in normal operation open, . connecting the electrical switching means across the, , :.

pair of closed loops, such that closing of the electrical switching means creates a short circuit between the closed ':' loops, ' and such that in operation a network signal being transmitted through the port is interrupted, causing the protocol-enabled switching means to generate a protocol- ', .' based report.
13. A method according to claim ll, wherein in a case where the electrical switching means is by default and/or in normal operation closed, operably coupling the electrical switching means along one of the closed loop paths such that opening of the electrical switching means breaks the loop, and such that in operation a network signal being transmitted through the port is interrupted, causing the protocol-enabled switching means to generate a protocol based report.
14. A method of operably coupling an input of a non- protocol enabled device to a protocol-based network, the network comprising a protocol-enabled switching means, said protocol-enabled switching means comprising at least a first port; and the device comprising an electrical switching means operable to signify at least two device states, the method characterized by; connecting a pair of closed loops between two corresponding transmission and reception parts of said port; and operably coupling activation means of the electrical switching means to both closed loops. " , '. .:.
15. A method according to claim 14 further characterized by; smoothrectifying a network signal from said port to ' ', ' produce a DC output; operably coupling activation means of the electrical '.

switching means to said smoothed rectification means, ',,',: and such that upon a protocol-based command to enable the port, the electrical switch means is activated, and upon a protocol-based command to disable the port, the electrical switching means is deactivated.
16. A method according to claim 11 or 14 wherein information about nonprotocol enabled devices and/or their state types is associated with their corresponding port - numbers on the network.
17. A method according to claim 16 wherein software located upon the network, in the case of output from a non protocol enabled device, interprets differently the protocol based message generated by the protocol-enabled switching means, according to the type of device and/or output state types associated with the port number.
18. A method according to claim 16 or 17 wherein software located upon the network, in the case of input to a non- protocol enabled device, interprets differently protocol- based commands from the network, according to the type of device and/or input state types associated with the port number.
19. A method or Apparatus according to any one of the preceding claims, wherein the protocol-enabled switching.' means is an Ethernet switch.,,j, ',
20. A method or Apparatus according to claim 19 wherein 'i' the network signal is an Ethernet idle pattern.À'
21. A method or Apparatus according to any one of the preceding claims, wherein the protocol-enabled switching ', means is a Network hub.
22. A method or Apparatus according to any one of the preceding claims, wherein the protocol-enabled switching means is a Router.
23. A method or Apparatus according to any one of the preceding claims, wherein the protocol is an interned protocol (IF).
24. A method or Apparatus according to any one of the preceding claims, wherein the electrical switching means is a relay.
25. A method or Apparatus according to claim 24 wherein activation means of the electrical switching means is an electromagnetic actuator.
26. Apparatus according to claim 1 and substantially as hereinbefore described with reference to the accompanying drawings.
27. Apparatus according to claim 4 and substantially as.

hereinbefore described with reference to the accompanying,,,,:, drawings.
28. A method according to claim 11 and substantially as.,' hereinbefore described with reference to the accompanying drawings. ..

'..','
29. A method according to claim 14 and substantially as hereinbefore described with reference to the accompanying drawings.