System for routing multicast paging / talkback call audio over Internet between VOIP devices in different LAN

Abstract

The present disclosure relates to a system for routing multicast paging / talkback call audio between VOIP devices in different LANs via the Internet. The gateway is configured to be located in a LAN of an IP-based unit having an SP2 function for paging / talkback audio using multicast technology. The gateway converts the multicast call traffic into unicast call traffic for transmission over the Internet to one or more IP units with SP2 functionality in different LANs. The present invention relates to an apparatus and method for connecting paging / talkback line audio of an SP2 system between different facilities having different LANs, each provided with a respective gateway configured to convert unicast traffic back to multicast traffic to connect paging / talkback line audio of the SP2 system between different facilities having different LANs, thereby eliminating the need for a dedicated and expensive wide area network for inter-LAN communications between SP2-enabled IP units. The permission and configuration server is configured to maintain a database of IP addresses allocated to each gateway of a respective LAN or Internet group, and to communicate group IP addresses to the gateways.

Description

[0001] This application is a divisional application of an invention patent application with an application date of June 18, 2019, application number 201980040968.8, and invention name "System for routing multicast paging / intercom call audio between VOIP devices in different LANs via the Internet". Technical Field

[0002] The illustrative embodiments relate to apparatus and methods for interconnecting Internet Protocol (IP) communication devices employing multicast technology for page / party communications in a local area network (LAN) with other such IP communication devices in a different LAN using the Internet. Background Art

[0003] Internet Protocol (IP) communication units or stations that use multicast technology for paging / intercom communications in a local area network (LAN) are commercially available from GAI-Tronics Corporation of Mohnton, Pennsylvania. For example, GAI-Tronics Corporation produces both conventional shelled and ruggedized products for providing Voice over Internet Protocol (VoIP) phones, Public Address and General Alarm (PA / GA) systems, and other communication system units or stations. GAI-Tronics Corporation's IP units based on multicast technology can be used in many applications (e.g., in-plant paging systems to complete plant communications, monitoring, and emergency notifications) and in many environments such as on oil rigs or in refineries or railroad systems.

[0004] Currently, to connect the paging / intercom audio of a multicast-based IP communication station with the corresponding LAN between different facilities, a dedicated and expensive wide area network (WAN) would typically be required to allow all IP units to communicate with each other. Summary of the invention

[0005] The foregoing and other problems are overcome, and additional advantages are achieved, by the illustrative embodiments.

[0006] According to an illustrative embodiment, a gateway is configured to send Internet Protocol (IP) unit multicast audio call traffic via the Internet, including: a communication interface to a local area network (LAN) to which the IP unit is connected. The IP unit is configured to send and receive paging audio about other IP units and participate in intercom line calls (partyline calls) with other IP units using multicast. The gateway also includes a communication interface to the Internet, a memory device, and a processor. The memory device is configured to store the IP address of each of one or more gateways in at least one specified group that are located in different LANs and perform inter-LAN communication with the gateway, and store configuration information, including sockets for paging audio and intercom line calls assigned to IP units in the LAN. The processor is configured to receive multicasts from IP units in the LAN, and convert the multicasts into corresponding unicasts using the IP addresses of the gateways in the specified group, and then transmit them to them via the Internet. In addition, the processor is configured to receive unicasts from the Internet, and convert the unicasts into multicasts provided to corresponding sockets based on the configuration information of the IP units in the LAN.

[0007] According to one aspect of the illustrative embodiment, the processor is further configured to request an IP address of a gateway assigned to one or more inter-LAN groups from a server and store the IP address in the memory device and the corresponding group identifier. For example, the server is configured to store configuration information of the IP unit in the corresponding LAN.

[0008] According to an aspect of the illustrative embodiment, the processor is configured to convert multicast Real Time Protocol (RTP) traffic in the multicast to unicast RTP traffic and route the unicast RTP traffic to an IP address of a gateway in a specified one of the groups.

[0009] According to an illustrative embodiment, a method for sending multicast audio call traffic between Internet Protocol (IP) units via the Internet is provided, the method comprising: providing a gateway at a corresponding local area network (LAN) of the IP unit. The IP unit is configured to send and receive paging audio with respect to other IP units and to participate in intercom calls with other IP units using multicast. The method further comprises assigning each of the gateways to one or more Internet groups, and storing, for each Internet group, an IP address corresponding to the gateway assigned to the Internet group. The method further comprises receiving, at the gateway, a multicast from an IP unit in its LAN corresponding to at least one of the paging audio and the intercom audio, and converting the multicast to a corresponding unicast using an IP address of a corresponding gateway in a designated one of the Internet groups; and then transmitting the unicast via the Internet.

[0010] According to one aspect of the illustrative embodiment, the unicast includes a stream of packets having overhead information and an audio payload. The overhead information identifies an IP unit that is a source of the audio payload and provides a sequence number that allows the IP unit receiving the packets to organize and mix the stream according to at least one of paging audio and intercom call audio in a multicast.

[0011] According to an aspect of the illustrative embodiment, the method further includes receiving a unicast from the Internet at a corresponding gateway in the designated Internet group, and the corresponding gateway converting the unicast into a multicast.

[0012] According to an aspect of the illustrative embodiment, the method further includes storing, using at least one of the gateway and the server, configuration information including sockets for paging audio and intercom calls assigned to IP units corresponding to each of the gateways in the LAN.

[0013] According to an aspect of the illustrative embodiment, the method further includes providing, by a corresponding gateway of the gateways in the designated internet group, multicast to the corresponding socket based on configuration information of an IP unit associated with the corresponding gateway in the LAN.

[0014] Additional and / or other aspects and advantages of the illustrative embodiments will be set forth in the following description, or will become apparent from the description, or may be learned by practice of the illustrative embodiments. The illustrative embodiments may include VoIP phone units having one or more of the above aspects and / or one or more features and combinations thereof, and systems and methods for operating these VoIP phone units. The illustrative embodiments may include one or more features and / or combinations of the above aspects, such as those recited in the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The above and / or other aspects and advantages of the exemplary embodiments will be more readily understood through the following detailed description taken in conjunction with the accompanying drawings, in which:

[0016] Figure 1 A system is depicted in which IP units are deployed in different local area networks (LANs), but cannot communicate with IP units in other LANs.

[0017] Figure 2 A system for providing Internet connectivity between IP units deployed in different LANs constructed in accordance with an illustrative embodiment is depicted.

[0018] Figure 3 is a flow chart depicting the operation of a gateway for inter-LAN calling functionality between IP units according to an illustrative embodiment;

[0019] Figure 4is a flow chart describing the operation of a licensing and configuration server for inter-LAN calling functionality between IP units according to an illustrative embodiment;

[0020] Figure 5A and 5B is a perspective view of an illustrative housing for an IP unit according to an illustrative embodiment;

[0021] Figure 5C illustrates an example IP unit having a touch screen display constructed in accordance with an illustrative embodiment; and

[0022] Figure 6 is a block diagram of components of an IP unit in accordance with an illustrative embodiment.

[0023] Throughout the drawings, like drawing reference numerals will be understood to refer to like elements, features, and structures. DETAILED DESCRIPTION

[0024] Reference will now be made in detail to the illustrative embodiments illustrated in the accompanying drawings.The embodiments described herein are illustrated by reference to the accompanying drawings but are not limiting of the claims.

[0025] Illustrative embodiments will be described herein with reference to one or more Internet Protocol (IP) units, some of which are described in more detail below as examples. Generally speaking, an IP-based product or unit 16 allows a user to make IP phone calls based on the Session Initiation Protocol (SIP), such as point-to-point calls, voice paging, and intercom line communications, when operating as a VoIP phone in a phone operating mode. The call can be hands-free or handset mode, depending on how the unit 16 is established (i.e., with a handset, or with a flush-mounted speaker and microphone and a speed dial button or a help button). The IP unit 16 ensures that a SIP server / IP PBX is available for proper registration. Some example operations of a VoIP phone are described in co-owned WO / 2015 / 031624, which is incorporated herein by reference.

[0026] The IP unit 16 may also have serverless page / party (SP2) functionality as described in WO 2016 / 100795, which is incorporated herein by reference. The IP unit 16 with SP2 functionality is a paging and intercom system that combines the simplicity of "push to page, release to intercom" operation with multicast Internet Protocol Voice (VoIP) technology to provide almost instant communication in the most demanding environments. The IP unit 16 with SP2 functionality is wired to the nearest network switch using, for example, CAT5 / CAT5E Ethernet cable or fiber optic cable. Local power can be provided to the IP unit 16 as a separate power cord or included in the hybrid power / network cable. Multiple IP units 16 with SP2 functionality can operate in a "serverless" system. While other paging systems rely on servers to route calls and manage systems, the SP2 functionality uses multicast technology, thereby bypassing the need for servers and bringing many benefits described below.

[0027] Reference below Figure 5C One type of illustrative IP unit 16 is described having a universal application platform (UAP) for operating as a multi-function device over Ethernet in any of a variety of operating modes. The operating modes may include, but are not limited to, for example, a "serverless" paging-intercom (SP2) system mode, a VoIP phone mode, an IP access panel mode (e.g., an alarm activation / general alarm (PA / GA) system for a central public address), a point-to-point intercom mode, etc., all of which can be operated by utilizing a graphical user interface (GUI) screen designed specifically for each operating mode on a touch screen display.

[0028] Combine the following Figure 5A , 5B , 5C and 6 describe additional aspects of the illustrative IP-based unit 16.

[0029] Server-less paging / intercom (SP2) capability over the Internet

[0030] It is desirable to connect SP2 / UAP systems for point-to-point audio and paging / intercom audio between different facilities (eg, for communications between an oil rig and a land-based facility). Figure 1 The example implementation depicted in FIG. 1 includes multiple local area networks (LANs), wherein an IP unit 16 in a LAN or subnet 12a cannot communicate with an IP unit 14 in another LAN or subnet 12b, 12c, ..., 12n. Accomplishing inter-LAN or inter-subnet 12 communication may require the use of a dedicated and expensive wide area network (WAN) to allow all IP units 16 to communicate with each other. However, according to the following combined Figure 2The illustrated embodiment described, an alternative to using such an expensive dedicated WAN is to utilize the Internet in place of the WAN to connect these various systems.

[0031] A system without inter-LAN or inter-subnet 12 communications (i.e., Figure 1 ), and then describe the use of LAN or subnet 12 communication Figure 2 Reference is made to an illustrative embodiment of Figure 1 , multiple IP units 16 are deployed in a string or ring topology, with each phone linked only to its neighbors, except for the two end IP units 16 that are connected to the wider network via other devices. In the example VoIP system 10, each of the multiple groups 12a, ..., 12n of IP units 16 has its own separate subnet and virtual local area network (VLAN) (e.g., to limit multicast packets) via optical fibers 14a, ..., 14n connected to it by all group members 16. The use of VLANs allows local multicasts to be contained within a group 12 or string. VLAN IDs do not have to be unique on the system 10.

[0032] Because of the bidirectional fiber 14, the switch 22 is configured for port blocking to prevent network loops. Each subnet terminates at a switch 22 that supports a spanning tree protocol (e.g., STP) to prevent network loops. Each end IP unit in the group 12 can be connected to switches 221 and 222, that is, each string or group 12 can have two network switches. Each switch 22 is connected to the wider network 18 via a layer 3 router 20. Since only one router is active at a time, the router 20 can run a redundancy protocol (e.g., Virtual Router Redundancy Protocol or VRRP) so that the group 12 or string can still work in the event of the loss of one of the routers 20. The active router 20 serves as the gateway for the string subnet of the group 12. The switches 221 and 222 in the group 12 have a direct connection between them via the network cloud 18 (e.g., a physical link or an OSI layer 2 connection through a service provider). In the event of a link loss within the string of the group 12, routes are retained from each phone 16 to the active router 20 or gateway, and from each phone 16 to all other phones 16 in the string (for multicast conferencing).

[0033] Continue to refer Figure 1 , SIP server 24 and operator station 26 are also connected to cloud 18. For clarity, Figure 1The connection to the "cloud" or network 18 is omitted. As described above, the network 18 consists of routers 20 that form a single layer 3 network architecture, supporting multi-protocol label switching (MPLS) or similar data bearing protocols. For redundancy, the VoIP phones 16 are connected in a fiber ring 14, which is connected to the wider network 18 by means of network routers 20. However, spurs (i.e., only one end terminates at the switch 22) may be generated, resulting in loss of redundancy. The network 18 to which the fiber ring 14 of the group 12 is connected is configured to allow a large number of groups 12 to be deployed, and there are groups 12 with, for example, up to 20 or more IP units 16. The network 18 allows the IP units 16 in any group 12 to communicate with a common SIP server 24 in the network without conflict. In addition, the groups 12 are resilient enough to still operate in the event of the loss of any one phone 16 or link associated with each group 12.

[0034] according to Figure 2 The advantageous illustrative embodiment shown, the Internet 18 can be used in the system 200 to add the ability to allow peer-to-peer audio and server-free paging / intercom (SP2) communications between IP units 16 on different local area networks (LANs) 212n. However, Internet service providers (ISPs) typically block multicast traffic in order to minimize unnecessary traffic to the Internet. When IP units (e.g., SP2 / UAP type IP units 16) utilize multicast traffic to pass paging / intercom audio between IP units 16 on the LAN, a gateway device 202n configured according to the illustrative embodiment is used to convert multicast real-time transport protocol (RTP) traffic to unicast RTP traffic and vice versa.

[0035] according to Figure 2 In the illustrative embodiment of the present invention, gateway 202 is configured to route multicast traffic from IP unit 16 destined for remote LAN 12 to Internet 18 by converting the multicast RTP traffic into unicast RTP traffic, thereby avoiding being blocked by any ISP. Unicast RTP traffic is routed to IP units 16 belonging to inter-LAN or Internet groups (e.g., Figure 2 Each receiving gateway 202 is configured to convert the RTP traffic inbound from the Internet 18 back into multicast traffic and broadcast it on the LAN 212 to which it is connected. These operations are performed by the gateways 202n in the Internet group specified by the licensing and configuration server 204. In other words, for Figure 2In the illustrated inter-LAN or internet group, gateway 202A can unicast RTP to gateways 202B and 202C. Gateway 202B can unicast RTP to gateways 202A and 202C. Gateway 202C can unicast RTP to gateways 202A and 202B. It should be understood that licensing and configuration server 204 can coordinate other internet groups having the same or different LANs 212n and different numbers of LANs as members.

[0036] In order for the gateways 202n to determine their destination within their internetgroup(s), they are configured to determine the outward-facing or public IP address of all gateways 202 within a particular inter-LAN or internetgroup. Figure 2 The licensing and configuration server 204 shown is completed. The host name of the server 204 is configured in each gateway 202, and the relevant client information to identify the one or more groups identified by the gateway 202n. The licensing and configuration server 204 can, for example, maintain a database, such as a table including one or more LAN-to-LAN or Internet group identifiers and the IP address of each gateway assigned to each LAN-to-LAN or Internet group. The licensing and configuration server 204 performs network address translation (NAT) and management of subscription fees for inter-LAN communication support services. Each gateway 202 contacts the server 204 and obtains the IP addresses of all gateways 202 in its assigned (one or more) Internet groups, thereby allowing each gateway 202 to directly unicast RTP directly to all other gateways 202 in the Internet group via the Internet IP address of each gateway. The server 204 can be configured to provide this service as a subscription service that requires, for example, a monthly or annual fee, or as a free service. Customers / users can access the server 204 via the web and configure the gateways 202 that should be part of the selected Internet group. As an additional service, the configuration aspect of server 204 can provide configuration of IP units 16 on each LAN 212n, thereby eliminating the need for a local configuration server on each LAN 212.

[0037] Additional monitoring may be performed to ensure that the end-to-end path of each gateway 202 reaches the other gateways 202 in its internetwork group. This may be done, for example, using a heartbeat protocol to ensure that connectivity is always available.

[0038] according to Figure 2The inter-LAN call traffic of the advantageous illustrative embodiment depicted in has no impact on the local operation of the system with the SP2-capable IP unit 16 on a particular LAN 212n. The gateway 202n is configured to broadcast the converted inbound RTP to the correct multicast socket on the LAN 212n, from which the connected IP unit 16 is configured to receive and broadcast through its speakers / headphones. In operation, the IP unit 16 is unaware of the existence of the gateway 202n, and the gateway 202n is unaware of the IP unit 16 in its LAN 212n. The gateway 202n simply creates a bridge between different LANs 212n to transmit the normally blocked multicast RTP over the Internet.

[0039] More specifically, as described in WO 2016 / 100795, the IP unit 16 with SP2 function uses multicast technology that enables multiple IP devices configured to listen to a given broadcast address to receive pages from a single source over the network and listen to and participate in intercom lines. IT personnel or other administrators can assign or program multicast addresses / ports or sockets to the corresponding intercom and paging lines used by the IP unit 16. One or more IP units 16 can be designated as a master station to manage the configuration and update of any IP unit 16 in its system or LAN 212 using a mutual provisioning mode and command channel. For example, according to the system configuration, a multicast address is assigned to a designated paging socket and intercom line socket used by the IP unit 16 with SP2 function in LAN 212n. Once configured, the IP unit 16 with SP2 function operates to listen to its configured paging socket for received audio, transmit audio on its configured paging socket, and participate in an intercom line conference on its configured partial line socket according to the system configuration. In other words, an IP unit 16 can listen to RTP on the socket it is configured to listen to as part of a designated group and convert the RTP to audio for playback. Each IP unit 16 in a group can listen to the intercom line, and multiple people can broadcast on the same intercom line without the need for an IP-PBX or similar equipment.

[0040] For example, for intercom line operation, the intercom line selector switch 106 ( Figure 5C ) has a multicast address / port or socket assigned to each of the five intercom lines for transmission and listening when selected. The IP unit 16 listens on the paging socket. When an intercom line is selected and the handset is off-hook, if configured, the amplifier audio is muted and the audio from the selected multicast socket is routed to the headset and the audio from the handset microphone is transmitted on the multicast socket.

[0041] In addition to the five intercom line sockets, the IP unit 16 can also listen for inbound paging audio on up to, for example, eight other configurable paging sockets. Each paging socket has a priority from 1 to 8 associated with it. For paging operations, when the IP unit 16 goes off-hook in an intercom line conversation, the unit can broadcast the received paging audio. Multicast sockets are used to transmit and monitor paging lines. Paging audio is not usually monitored in the headset, but the IP unit 16 can be configured so that when the lever is pressed, one station can hear the paging audio of another station in the headset. The IP unit 16 performs idle listening on all configured paging sockets, routing the received paging audio to the amplifier appropriately. Audio is not routed to the paging line unless the handset is off-hook and the lever is pressed. When the lever is pressed, the audio from the specified paging line socket is routed to the headset, and the audio from the microphone is routed to the paging line socket.

[0042] Thus, by extracting the payload data encoded within the RTP packet stream on the socket, audio is received from the LAN 212n: (a) the IP unit 16 is configured to listen; and (b) the gateway 202n knows when to convert the unicast RTP traffic from the Internet into a multicast message for the IP unit 16 in its corresponding LAN 212n. Thus, the SP2-enabled IP units 16 on each LAN 212n can be unaware of the gateway 202n on that LAN 212n and simply receive multicast audio on the multicast socket they are listening on. Furthermore, the IP units 16 do not have to communicate with the licensing and configuration server 204 or the Internet 18.

[0043] The RTP layer is the core mechanism behind the transmission and reception of audio at the IP unit 16. In most cases, the RTP layer of the transport packet is built according to RFC 3550. Compressed frames are transmitted across the network from the IP unit 16 at an auto-negotiated rate of 10 or 100 Mbit / s using RTP over IP. Multicast addressing is used so that each packet can be received by multiple IP units 16. In addition to the encoded audio payload, each data packet is also constructed to include, for example, a unique RTP stream ID (e.g., a synchronization source (SSRC) identifier that uniquely identifies the source of the stream) and other overhead information. Each layer of the packet structure complies with the relevant Internet standard RFCs. For example, an incoming multicast packet can include a unique source ID in addition to a sequence number. For each packet, the sequence number is incremented, which allows the receiving IP unit 16 to sort it appropriately to recreate the digital audio stream. The source ID or SSRC included in each RTP packet is a fixed number unique to each IP unit 16. The receiving IP unit 16 can receive multiple streams from multiple IP units 16. The SSRC is used to keep the streams organized so that the RTP streams from each transmitting IP unit 16 can be mixed appropriately in the receiving IP unit 16 .

[0044] refer to Figure 3 , the licensing and configuration server 204 is configured to receive configuration information from a system user or administrator, who may assign IP units 16 in a LAN 212 to one or more inter-LAN or (one or more) internet groups that include IP units 16 of one or more other LANs 212n (block 300). The licensing and configuration server 204 then updates its database of inter-LAN or internet groups and the corresponding IP addresses of the gateways 202n assigned to each of these groups (block 302). Each gateway 202 may send a request for the IP address of the gateway assigned to its group(s) (block 304), and the licensing and configuration server 204 responds to these requests with the requested information (block 306). The gateway 202 then uses the IP address of the gateway 202n in its selected inter-LAN or internet group to convert the multicast message into a unicast message to each corresponding IP address in its group.

[0045] refer to Figure 4, the gateway 202 is configured to obtain the IP address of the gateway 202n assigned to its selected inter-LAN or Internet group (e.g., obtained from the licensing and configuration server 204) (box 400). When outgoing call traffic is received from the IP unit 16 in the gateway's LAN 212 (box 402) and the call traffic contains multicast RTP traffic (e.g., for SP2 feature call / intercom line audio) (box 404), the gateway uses the IP address of the gateway assigned to its selected inter-LAN or Internet group to convert the multicast RTP traffic to unicast traffic (box 406). The converted call traffic is transmitted to other LANs using the Internet (box 408).

[0046] Continue to refer Figure 4 , the gateway 202 is configured to receive incoming call traffic via the Internet (box 410). If the incoming call contains RTP traffic (box 412), the gateway converts the RTP traffic into multicast RTP traffic (box 414) before transmitting the RTP traffic to the IP unit with SP2 function in its LAN 212.

[0047] Illustrative IP Unit 16

[0048] The IP unit 16 typically has a speaker 61a and a microphone 61b integrated with the unit panel or provided in the handset 61, and an optional push-to-talk (PTT) non-locking button, such as Figure 5A , 5B Shown and combined Figure 6 Some IP units 16 may have up to two separate memory number auto-dial non-locking buttons (e.g., Figure 5B The microphone 61b on the unit 16 remains muted unless PTT is pressed. When a call is received, a reminder ring tone can be emitted from the speaker 52. The power requirements of these IP units 16 can be met by batteries charged by local solar panels, or can be provided via wireless power (e.g., Power over Ethernet) or wired power. If a call is in progress, pressing the memory number autodial button ends the call; otherwise, it will initiate a call to a preprogrammed number. For example, if Figure 5B As shown, when two memory number auto-dial buttons 47a, 47b are provided on the IP unit 16, pressing either button will end the ongoing call, or initiate a call to the pre-programmed number associated with the button. The buttons may be optionally prioritized. If in its configuration, the button ending the call may also be optional. The number of buttons provided is limited only by the number required by the application.

[0049] refer to Figure 5C, the IP-based unit 16 is configured in a housing with a handset 61, but can also be hands-free. Figure 5C The GUI screen 100 in FIG. 1 shows an operation mode selection button 102 , wherein an SP2 mode button 104 is selected on the SP2 mode screen. Figure 5C The SP2 mode screen 100 in FIG. 1 includes intercom line buttons 106 (e.g., five buttons, but a different number of intercom line buttons may be provided) and paging destinations indicated at 108. In this mode of operation, the IP unit 16 provides all of the capabilities of the hardware-based SP2 currently available and described in the commonly owned WO 2016 / 100795 incorporated herein by reference, but with several enhanced capabilities. These enhanced capabilities include, but are not limited to, for example, the ability to access more than the current maximum of five intercom lines indicated at 106. Now, instead of being numbered 1 to 5, the intercom lines can be named using a GUI screen on the touch screen display 46. In addition, the IP unit 16 can indicate the intercom line currently being used by the other party to allow for quick intercom line selection. The example IP unit 16 shown has the ability to transmit to five paging areas numbered 1 to 5. Through the enhancement of the GUI screen on the touch screen display 46, the areas can also be named (e.g., alphanumerically and / or using GUI symbols). The display 46 may indicate which zones have activity and which zone is currently broadcasting through the amplifier and speaker 61 of the unit 16. However, it should be understood that other types of IP units may be used to send IP calls to IP units in other LANs in accordance with the illustrative embodiments.

[0050] The SP2-enabled IP unit 16 is fast. Since no server is required to establish call routing and conference bridges, the SP2-enabled IP unit 16 can provide direct one-way paging and full-duplex "intercom line" communications. In addition, since the SP2-enabled IP unit 16 can operate in a server-less system, it can be easily integrated into an existing IP network. This can greatly reduce the installation cost of the SP2 system and simplify the plant data architecture. The SP2-enabled IP unit 16 is simple because no keyboard is required and no expansion is required for storage. The user simply lifts the handset, selects the paging zone, squeezes the handset lever, and the announcement is made through the system speaker. The user can release the lever and talk on one of the five available intercom lines. As Figure 5A and 5C As shown, the SP2-enabled IP unit 16 may be equipped with a handset 61 for paging and intercom, or may not have such a handset, for example, if only paging coverage is required. Figure 5B Handset shown.

[0051] Figure 6An example IP unit 16 is shown. Figure 6 As shown, the VoIP phone unit 16 can be provided with a control block or module 44, a signal conditioning block or module 42, a power block or module 40, and an earpiece 18 or a hands-free microphone 62 and a speaker 61, for example. The control module 44 is described in more detail below. The signal conditioning module 42 is connected to an Ethernet network, for example, wirelessly or using an optical cable or copper wire via an Ethernet interface 14. The unit 16 is provided with a touch screen display 46, a video camera sensor and lens 48, and an external user interface port 50. The unit 16 can have a power block or module 40 to receive power via Power over Ethernet (PoE) or POE Plus, but other power sources can be used.

[0052] Wireless communication interfaces (e.g., IEEE 802.11, WiFi, Bluetooth TM or other protocols) 60 to allow wireless communication between the unit 16 and another device (such as a smart phone, a sensor, an IoT device, etc.). The packet structure in the RTP layer employed according to the illustrative embodiment can be configured to accommodate different signal traffic flows and different applications, such as commands or transmission data sent from an IP unit to another IP unit in a different LAN, where the commands or transmission data include power signals, sensor data, device commands, etc. for remote operation and communication with various devices (e.g., devices in HVAC systems, lighting control systems, security systems, entertainment systems, etc.).

[0053] The touch screen display 46 may be rugged, i.e., it may be comprised of, for example, an impact-resistant screen or screen layers, whereby for HA compliance reasons, glass is laminated or bonded to prevent glass breakage from breaching any seals disposed within the unit 16. According to one illustrative embodiment, the touch screen display 46 may be an automotive-grade liquid crystal display (LCD) screen (e.g., a 7-inch display) capable of withstanding a considerable range of temperatures (e.g., -30°C to 70°C) and having optional full sunlight and / or wide-angle visibility as expected in an automotive environment. Additionally, the display 46 is mounted in the housing of the unit 16 to withstand damage and weather, and to comply with HA classification requirements as required.

[0054] The unit 16 is provided with a magnetic hook switch sensor (e.g., coupled to a cradle of the handset 18, not shown), whose output 63 can be coupled to a signal conditioning block or module 42 to provide on / off hook status data of the handset 18 to the control module 44. As described above, the signal conditioning module 42 is configured to provide public address (PA) speaker audio 68 and earphone / speaker audio 62 from the control module 44 for the handset or hands-free speaker, and to receive microphone audio 64 for the control module 44 from the handset or a separate microphone. The signal conditioning module 42 is also configured to provide input data and DC power from the touch screen 46 to the VoIP control board 44. As indicated at 54, general purpose monitored input / output (I / O) is provided.

[0055] The signal conditioning module 42 and the control module 44 are configured to process the Ethernet data 58. The control module 44 in the unit 16 may include a programmable processor 92 and an integrated or separate memory 94. As described above, the microprocessor 92 may be, for example, a digital signal processor (DSP) or a system on a chip (SOC) with standard VoIP / SIP software. The control module 44 may employ, for example, an audio CODEC (e.g., 8kHz G711A / U law) to provide full-duplex hands-free voice; that is, in a call, the audio of the unit 16 will be full-duplex (i.e., transmitting and receiving simultaneously without switching).

[0056] According to aspects of the illustrative embodiment, the units 16 are programmed (e.g., via software code instructions executed by their respective processors 92 and, for example, in accordance with the universal application platform 98) to establish and terminate point-to-point calls and participate in intercom line calls, as well as other operations in accordance with each of a plurality of operating modes. As described above and in accordance with an embodiment, the VoIP phone units 16 are configurable multi-function devices having a universal application platform 98 that is pre-programmed to operate in any of a plurality of operating modes. The plurality of operating modes may be, but are not limited to, two or more of the following modes: VoIP phone mode, server-less paging-intercom station mode, access panel mode, server-less point-to-point intercom mode, intercom line call mode, and video call mode, among others.

[0057] It will be understood by those skilled in the art that the present disclosure is not limited to the details of the constructions and the arrangement of parts thereof as set forth in the above description or illustrated in the accompanying drawings. The embodiments herein can have other embodiments and can be practiced or executed in various ways. Moreover, it will be understood that the wording and terminology used herein are for the purpose of description and should not be considered as restrictive. The use of "including", "comprising" or "having" and its variations herein is intended to cover the items listed thereafter and their equivalents and additional items. Unless otherwise limited, the terms "connect", "couple" and "install" and their variations herein are widely used and include direct and indirect connections, couplings and installations. In addition, the terms "connect" and "couple" and their variations are not limited to physical or mechanical connections or couplings. In addition, terms such as upper, lower, bottom and top are relative and are used to help illustrate, but are not restrictive.

[0058] The components of the illustrative apparatus, systems, and methods employed in accordance with the illustrative embodiments may be implemented at least in part in digital electronic circuitry, analog electronic circuitry, or in computer hardware, firmware, software, or a combination thereof. For example, these components may be implemented, for example, as a computer program product, such as a computer program, program code, or computer instructions tangibly embodied in an information carrier or in a machine-readable storage device, for execution or control of operations by a data processing apparatus such as a programmable processor, a computer, or multiple computers.

[0059] The computer program may be written in any form of programming language, including compiled or interpreted languages, and may be deployed in any form, including as a stand-alone program or as a module, component, subroutine, or other unit suitable for use in a computing environment. The computer program may be deployed to execute on one computer or on multiple computers at one site or distributed on multiple sites and interconnected by a communication network. Moreover, the functional programs, codes, and code segments for implementing the illustrative embodiments may be easily interpreted as being within the scope of the claims illustrated by the illustrative embodiments by programmers in the field of the illustrative embodiments. The method steps associated with the illustrative embodiments may be performed by one or more programmable processors that execute computer programs, codes, or instructions to perform functions (e.g., by operating on input data and / or generating output). For example, the method steps may also be implemented by a dedicated logic circuit system, such as an FPGA (field programmable gate array) or an ASIC (application-specific integrated circuit), and the apparatus of the illustrative embodiments may be implemented as a dedicated logic circuit system, such as an FPGA or an ASIC.

[0060] The various illustrative logical blocks, modules, and circuits described in conjunction with the embodiments disclosed herein may be implemented or executed with a general purpose processor, a digital signal processor (DSP), an ASIC, an FPGA, or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but alternatively, the processor may be any conventional processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0061] As an example, processors suitable for executing computer programs include general and special microprocessors, and any one or more processors of any type of digital computer. Typically, the processor will receive instructions and data from a read-only memory or a random access memory or both. The basic elements of a computer are a processor for executing instructions and one or more memory devices for storing instructions and data. Typically, a computer will also include one or more large-capacity storage devices for storing data, or operably coupled to receive data from the one or more large-capacity storage devices or transfer data to the one or more large-capacity storage devices or both, such as magnetic disks, magneto-optical disks, or optical disks. Information carriers suitable for implementing computer program instructions and data include all forms of non-volatile memory, including semiconductor memory devices, such as electrically programmable read-only memory or ROM (EPROM), electrically erasable programmable ROM (EEPROM), flash memory devices, and data storage disks (e.g., magnetic disks, internal hard disks or removable disks, magneto-optical disks, and CD-ROM and DVD-ROM disks). The processor and memory can be supplemented by or incorporated into a dedicated logic circuit system.

[0062] Those skilled in the art will appreciate that information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0063] The technician will also recognize that the various illustrative logic blocks, modules, circuits and algorithm steps described in conjunction with the embodiments disclosed herein can be implemented as electronic hardware, computer software or a combination of the two. In order to clearly illustrate this interchangeability of hardware and software, various illustrative components, boxes, modules, circuits and steps have been generally described above in terms of their functions. Whether this function is implemented as hardware or software depends on the specific application and the design constraints imposed on the entire system. The technician can implement the described functions in different ways for each specific application, but this implementation decision should not be interpreted as causing a departure from the scope of the claims exemplified by the illustrative embodiments. The software module can reside in a random access memory (RAM), flash memory, ROM, EPROM, EEPROM, register, hard disk, removable disk, CD-ROM or any other form of storage medium known in the art. The exemplary storage medium is coupled to the processor so that the processor can read information from the storage medium and can write information to the storage medium. Alternatively, the storage medium can be integrated with the processor. In other words, the processor and the storage medium can reside in an integrated circuit or be implemented as discrete components.

[0064] Computer-readable non-transitory media include all types of computer-readable media, including magnetic storage media, optical storage media, flash memory media, and solid-state storage media. It should be understood that the software can be installed in a central processing unit (CPU) device and sold with it. Alternatively, the software can be obtained and loaded into the CPU device, including obtaining the software through a physical medium or distribution system, including, for example, obtaining the software from a server owned by the creator of the software or from a server that the owner of the software does not own but uses. For example, the software can be stored on a server for distribution over the Internet.

[0065] Unless otherwise stated in the appended claims, the description and drawings given above are intended to be examples only and are not intended to limit the illustrative embodiments in any way. It is particularly noted that the various technical aspects of the various elements of the various illustrative embodiments described above can be easily combined in a variety of other ways by those skilled in the art, all of which are considered to be within the scope of the claims.

Claims

1. A gateway (202) configured to send Internet Protocol unit multicast audio call traffic via the Internet (18), comprising: a communication interface connectable to a local area network (212) to which an Internet Protocol unit (16) is connected, the Internet Protocol unit (16) being configured to send and receive paging audio with respect to other Internet Protocol units (16) and to participate in intercom line calls with other Internet Protocol units (16) using multicast; a communication interface connectable to the Internet (18); A memory device configured to store: an internet protocol address of each of the one or more gateways (202) in at least one designated inter-LAN group, the inter-LAN group being located in different LANs (212) and performing inter-LAN communications with the gateways (202), and configuration information including sockets for paging audio and intercom line calls assigned to an Internet protocol unit (16) in a local area network (212); The processor is configured as: requesting from a remote database and storing in a memory device an Internet Protocol address assigned to a gateway (202) of each inter-LAN group performing inter-LAN communications with the gateway (202), each inter-LAN group including designated Internet Protocol units (16) from different LANs (212) that can communicate with each other via multicast, receiving a multicast from an Internet Protocol unit (16) in a local area network and converting the multicast into a corresponding unicast using an Internet Protocol address of a gateway (202) in a designated inter-local area network group corresponding to the multicast, and then transmitting the multicast to the Internet Protocol address via the Internet, the multicast being sent to Internet Protocol units (16) in one or more different local area networks (212) corresponding to the designated inter-local area network group, and receiving a unicast from the Internet (18) and converting the unicast into a multicast provided to a corresponding socket based on configuration information of an Internet protocol unit (16) in a local area network (212), The host name of the remote server that maintains the remote database and related client information are configured in the gateway to identify at least one designated inter-LAN group, wherein the remote database includes one or more inter-LAN group identifiers and an Internet Protocol address of each gateway assigned to each inter-LAN group, and wherein the gateway contacts the remote server and obtains the Internet Protocol addresses of all gateways in at least one designated inter-LAN group, thereby allowing the gateway to directly unicast to all other gateways in the designated inter-LAN group via the Internet Protocol address of each gateway.

2. The gateway (202) of claim 1, wherein the processor is further configured to store in the memory device a group identifier corresponding to each inter-LAN group with which the gateway (202) performs inter-LAN communications.

3. A gateway (202) as described in claim 2, wherein the remote database is configured to store configuration information of the Internet Protocol unit (16) in the corresponding local area network (212), and the configuration information includes sockets for paging audio and intercom line calls assigned to the Internet Protocol unit (16) in the local area network (212).

4. The gateway (202) of claim 1, wherein the processor is configured to convert multicast Real Time Protocol (RTP) traffic in the multicast into unicast RTP traffic and route the unicast RTP traffic to an Internet Protocol address of a gateway (202) in a specified group of the groups.

5. A method for sending multicast audio call traffic between Internet Protocol units (16) via the Internet (18), comprising: providing a gateway (202) at a corresponding local area network (212) of an Internet Protocol unit, the Internet Protocol unit (16) being configured to send and receive paging audio with respect to other Internet Protocol units (16) and to participate in intercom line calls with other Internet Protocol units (16) using multicast; allocating Internet protocol units (16) from different ones of the local area networks (212) to more than one internet group, and for each internet group, storing at each of the gateways (202) corresponding to the internet group an Internet protocol address of a gateway (202) corresponding to the Internet protocol unit (16) allocated to the internet group; receiving, at a gateway (202), a multicast from an internet protocol unit (16) corresponding to at least one of paging audio and intercom line audio in its local area network (212), the multicast being sent to a designated one of the internet groups, and converting the multicast into a corresponding unicast using a stored internet protocol address of a corresponding gateway (202) in the designated one of the internet groups; as well as transmitting the unicast via the Internet, wherein the host name of a remote server maintaining a remote database and related client information are configured in each gateway to identify more than one internet group, wherein the remote database includes one or more internet group identifiers and an internet protocol address of each gateway assigned to each internet group, and wherein each gateway contacts the remote server and obtains the internet protocol addresses of all gateways in more than one internet group, thereby allowing the gateway to directly unicast to all other gateways in the internet group via the internet protocol address of each gateway.

6. The method of claim 5 wherein the unicast comprises a stream of packets having overhead information and an audio payload, the overhead information identifying an Internet Protocol unit (16) that is the source of the audio payload and providing a sequence number that allows the Internet Protocol unit (16) receiving the packets to organize and mix the stream according to at least one of paging audio and intercom call audio in the multicast.

7. The method of claim 5, further comprising receiving a unicast from the Internet (18) at a corresponding gateway (202) in a designated Internet group, and the corresponding gateway (202) converting the unicast into a multicast.

8. The method of claim 7, further comprising: Configuration information is stored using at least one of the gateways (202) and a remote server, the configuration information including sockets for paging audio and intercom calls assigned to an Internet protocol unit (16) corresponding to each of the gateways (202) in the local area network (212).

9. The method of claim 8, further comprising: A corresponding gateway (202) in a designated internet group provides multicast to a corresponding socket based on configuration information of an internet protocol unit (16) associated with the corresponding gateway (202) in a local area network (212).

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