Patent Publication Number: US-2023134898-A1

Title: Handling Multiple Communication Requests

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application claims priority to and the benefit of U.S. Pat. Application Serial No. 17/515,161, filed Oct. 29, 2021, titled “HANDLING MULTIPLE COMMUNICATION REQUESTS,” the entire disclosure of which is hereby incorporated by reference. 
    
    
     FIELD 
     This disclosure relates to handling multiple communication requests, such as those that may be used with telephony services implemented over a network. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       This disclosure is best understood from the following detailed description when read in conjunction with the accompanying drawings. It is emphasized that, according to common practice, the various features of the drawings are not to-scale. On the contrary, the dimensions of the various features are arbitrarily expanded or reduced for clarity. 
         FIG.  1    is a block diagram of an example of an electronic computing and communications system. 
         FIG.  2    is a block diagram of an example internal configuration of a computing device of an electronic computing and communications system. 
         FIG.  3    is a block diagram of an example of a software platform implemented by an electronic computing and communications system. 
         FIG.  4    illustrates an example communication system in which handling multiple communication requests may be implemented. 
         FIG.  5    is a data flow diagram of an example of a sequence of operations for handling multiple communication requests. 
         FIG.  6    is a data flow diagram of an example sequence of operations for modification of Session Initiation Protocol (SIP) for handling multiple communication requests. 
         FIG.  7    illustrates a first example system with three caller devices calling one another within a threshold time period. 
         FIG.  8    illustrates a second example system with three caller devices calling one another within a threshold time period. 
         FIG.  9    illustrates an example system in which call merging and ownership assignment may be implemented. 
         FIG.  10    is a flowchart of an example of a technique for handling multiple communication requests. 
         FIG.  11    is a flowchart of an example of a technique for handling multiple communication requests with three or more parties. 
     
    
    
     DETAILED DESCRIPTION 
     Enterprise entities rely upon several modes of communication to support their operations, including telephone, email, and internal messaging. These separate modes of communication have historically been implemented by service providers whose services are not integrated with one another. The disconnect between these services, in at least some cases, requires information to be manually passed by users from one service to the next. Furthermore, some services, such as telephony services, are traditionally delivered via on-premises systems, meaning that remote workers and those who are generally increasingly mobile may be unable to rely upon them. 
     One type of system which addresses problems such as these includes a unified communications as a service (UCaaS) platform, which includes several communications services integrated over a network, such as the Internet, to deliver a complete communication experience regardless of physical location. Sometimes, two users of a communication service (e.g., a service implemented over a UCaaS platform or another voice, video or other type of communication service) might attempt to communicate with each other over a given communication service at approximately the same time (e.g., within 1 second, 3 seconds, 10 seconds or 30 seconds of each other). For example, two people might simultaneously (e.g., within 5 seconds or 15 seconds of one another) call each other if they did not agree on who would call whom for a scheduled meeting. This might lead to difficulty in connecting the two users, who might experience busy signals, connection errors or other connection issues. For example, those two people may each see that the other is calling them and disconnect from their own calls, further delaying their discussion and requiring additional efforts to establish an actual call session. Techniques for handling multiple communication requests that include the same users (e.g., A calls B and B calls A) and are generated within a threshold time period (e.g., 5 seconds or 15 seconds) of one another may be desirable. As used herein, a “user” may be an entity using a communication service, such as a voice calling, video calling, voice conferencing or video conferencing service. As used herein, a “communication request” may be any request by a user of a caller device to communicate with one or more other users of caller device(s) via the caller device(s). For example, a communication request may be completed by dialing a telephone number, selecting at least one entity from a contact list for initiation of a voice or video call or conference, or entering an entity identifier and selecting a voice call or video call command. 
     Implementations of this disclosure address problems such as these by handling multiple communication requests that are pending simultaneously and include common users (e.g., identified by telephone number, user account, or device identifier). 
     In some implementations, a communication server (e.g., which includes one or more proxy server) accesses indicia of a first invite to a first call being transmitted from a first caller device to a second caller device (e.g., a user of the first device dials a telephone number assigned for use to the second device) and a second invite to a second call being transmitted from the second caller device to the first caller device (e.g., a user of the second caller device dials a telephone number assigned for use to the first caller device). The first invite occurred within a threshold time period (e.g., 10 seconds or 30 seconds) of the second invite. In some implementations, the first invite and the second invite are pending (e.g., still attempting to connect and not yet accepted) during overlapping time periods (e.g., the time when the first invite is pending overlaps, at least in part, with the time period when the second invite is pending). In some implementations, the first caller device is identified based on the first caller device having dialed earlier than the second caller device. 
     The communication server transmits, to the first caller device, a control signal to initiate an active session (e.g., a telephone call, an audio-only conference or a video-enabled conference) in response to the first invite. After establishing the active session, the communication server determines that the second caller device is still attempting to initiate the second call and that the second call is not established. In response, the communication server dismisses the second call and causes the second calling device to join the active session, or merges the second call into the active session. The communication server conducts the active session according to a configuration (e.g., a recording configuration, time-limit configuration, or other policy-based configuration set for the user whose session was determined for use as the active session) associated with the first caller device. The active session is joined by at least the first caller device and the second caller device. In some cases, other device(s) are also involved in the active session, and the second caller device is notified of the presence of the other device(s). 
     To describe some implementations in greater detail, reference is first made to examples of hardware and software structures used to implement a system for handling multiple communication requests.  FIG.  1    is a block diagram of an example of an electronic computing and communications system  100 , which can be or include a distributed computing system (e.g., a client-server computing system), a cloud computing system, a clustered computing system, or the like. 
     The system  100  includes one or more customers, such as customers  102 A through  102 B, which may each be a public entity, private entity, or another corporate entity or individual that purchases or otherwise uses software services, such as of a UCaaS platform provider. Each customer can include one or more clients. For example, as shown and without limitation, the customer  102 A can include clients  104 A through  104 B, and the customer  102 B can include clients  104 C through  104 D. A customer can include a customer network or domain. For example, and without limitation, the clients  104 A through  104 B can be associated or communicate with a customer network or domain for the customer  102 A and the clients  104 C through  104 D can be associated or communicate with a customer network or domain for the customer  102 B. 
     A client, such as one of the clients  104 A through  104 D, may be or otherwise refer to one or both of a client device or a client application. Where a client is or refers to a client device, the client can comprise a computing system, which can include one or more computing devices, such as a mobile phone, a tablet computer, a laptop computer, a notebook computer, a desktop computer, or another suitable computing device or combination of computing devices. Where a client instead is or refers to a client application, the client can be an instance of software running on a customer device (e.g., a client device or another device). In some implementations, a client can be implemented as a single physical unit or as a combination of physical units. In some implementations, a single physical unit can include multiple clients. 
     The system  100  can include a number of customers and/or clients or can have a configuration of customers or clients different from that generally illustrated in  FIG.  1   . For example, and without limitation, the system  100  can include hundreds or thousands of customers, and at least some of the customers can include or be associated with a number of clients. 
     The system  100  includes a datacenter  106 , which may include one or more servers. The datacenter  106  can represent a geographic location, which can include a facility, where the one or more servers are located. The system  100  can include a number of datacenters and servers or can include a configuration of datacenters and servers different from that generally illustrated in  FIG.  1   . For example, and without limitation, the system  100  can include tens of datacenters, and at least some of the datacenters can include hundreds or another suitable number of servers. In some implementations, the datacenter  106  can be associated or communicate with one or more datacenter networks or domains, which can include domains other than the customer domains for the customers  102 A through  102 B. 
     The datacenter  106  includes servers used for implementing software services of a UCaaS platform. The datacenter  106  as generally illustrated includes an application server  108 , a database server  110 , and a telephony server  112 . The servers  108  through  112  can each be a computing system, which can include one or more computing devices, such as a desktop computer, a server computer, or another computer capable of operating as a server, or a combination thereof. A suitable number of each of the servers  108  through  112  can be implemented at the datacenter  106 . The UCaaS platform uses a multi-tenant architecture in which installations or instantiations of the servers  108  through  112  is shared amongst the customers  102 A through  102 B. 
     In some implementations, one or more of the servers  108  through  112  can be a non-hardware server implemented on a physical device, such as a hardware server. In some implementations, a combination of two or more of the application server  108 , the database server  110 , and the telephony server  112  can be implemented as a single hardware server or as a single non-hardware server implemented on a single hardware server. In some implementations, the datacenter  106  can include servers other than or in addition to the servers  108  through  112 , for example, a media server, a proxy server, or a web server. 
     The application server  108  runs web-based software services deliverable to a client, such as one of the clients  104 A through  104 D. As described above, the software services may be of a UCaaS platform. For example, the application server  108  can implement all or a portion of a UCaaS platform, including conferencing software, messaging software, and/or other intra-party or inter-party communications software. The application server  108  may, for example, be or include a unitary Java Virtual Machine (JVM). 
     In some implementations, the application server  108  can include an application node, which can be a process executed on the application server  108 . For example, and without limitation, the application node can be executed in order to deliver software services to a client, such as one of the clients  104 A through  104 D, as part of a software application. The application node can be implemented using processing threads, virtual machine instantiations, or other computing features of the application server  108 . In some such implementations, the application server  108  can include a suitable number of application nodes, depending upon a system load or other characteristics associated with the application server  108 . For example, and without limitation, the application server  108  can include two or more nodes forming a node cluster. In some such implementations, the application nodes implemented on a single application server  108  can run on different hardware servers. 
     The database server  110  stores, manages, or otherwise provides data for delivering software services of the application server  108  to a client, such as one of the clients  104 A through  104 D. In particular, the database server  110  may implement one or more databases, tables, or other information sources suitable for use with a software application implemented using the application server  108 . The database server  110  may include a data storage unit accessible by software executed on the application server  108 . A database implemented by the database server  110  may be a relational database management system (RDBMS), an object database, an XML database, a configuration management database (CMDB), a management information base (MIB), one or more flat files, other suitable non-transient storage mechanisms, or a combination thereof. The system  100  can include one or more database servers, in which each database server can include one, two, three, or another suitable number of databases configured as or comprising a suitable database type or combination thereof. 
     In some implementations, one or more databases, tables, other suitable information sources, or portions or combinations thereof may be stored, managed, or otherwise provided by one or more of the elements of the system  100  other than the database server  110 , for example, the client  104  or the application server  108 . 
     The telephony server  112  enables network-based telephony and web communications from and to clients of a customer, such as the clients  104 A through  104 B for the customer  102 A or the clients  104 C through  104 D for the customer  102 B. Some or all of the clients  104 A through  104 D may be voice over internet protocol (VOIP)-enabled devices configured to send and receive calls over a network  114 . In particular, the telephony server  112  includes a SIP zone and a web zone. The SIP zone enables a client of a customer, such as the customer  102 A or  102 B, to send and receive calls over the network  114  using SIP requests and responses. The web zone integrates telephony data with the application server  108  to enable telephony-based traffic access to software services run by the application server  108 . Given the combined functionality of the SIP zone and the web zone, the telephony server  112  may be or include a cloud-based private branch exchange (PBX) system. 
     The SIP zone receives telephony traffic from a client of a customer and directs same to a destination device. The SIP zone may include one or more call switches for routing the telephony traffic. For example, to route a VOIP call from a first VOIP-enabled client of a customer to a second VOIP-enabled client of the same customer, the telephony server  112  may initiate a SIP transaction between a first client and the second client using a PBX for the customer. However, in another example, to route a VOIP call from a VOIP-enabled client of a customer to a client or non-client device (e.g., a desktop phone which is not configured for VOIP communication) which is not VOIP-enabled, the telephony server  112  may initiate a SIP transaction via a VOIP gateway that transmits the SIP signal to a public switched telephone network (PSTN) system for outbound communication to the non-VOIP-enabled client or non-client phone. Hence, the telephony server  112  may include a PSTN system and may in some cases access an external PSTN system. 
     The telephony server  112  includes one or more session border controllers (SBCs) for interfacing the SIP zone with one or more aspects external to the telephony server  112 . In particular, an SBC can act as an intermediary to transmit and receive SIP requests and responses between clients or non-client devices of a given customer with clients or non-client devices external to that customer. When incoming telephony traffic for delivery to a client of a customer, such as one of the clients  104 A through  104 D, originating from outside the telephony server  112  is received, a SBC receives the traffic and forwards it to a call switch for routing to the client. 
     In some implementations, the telephony server  112 , via the SIP zone, may enable one or more forms of peering to a carrier or customer premise. For example, Internet peering to a customer premise may be enabled to ease the migration of the customer from a legacy provider to a service provider operating the telephony server  112 . In another example, private peering to a customer premise may be enabled to leverage a private connection terminating at one end at the telephony server  112  and at the other end at a computing aspect of the customer environment. In yet another example, carrier peering may be enabled to leverage a connection of a peered carrier to the telephony server  112 . 
     In some such implementations, a SBC or telephony gateway within the customer environment may operate as an intermediary between the SBC of the telephony server  112  and a PSTN for a peered carrier. When an external SBC is first registered with the telephony server  112 , a call from a client can be routed through the SBC to a load balancer of the SIP zone, which directs the traffic to a call switch of the telephony server  112 . Thereafter, the SBC may be configured to communicate directly with the call switch. 
     The web zone receives telephony traffic from a client of a customer, via the SIP zone, and directs same to the application server  108  via one or more Domain Name System (DNS) resolutions. For example, a first DNS within the web zone may process a request received via the SIP zone and then deliver the processed request to a web service which connects to a second DNS at or otherwise associated with the application server  108 . Once the second DNS resolves the request, it is delivered to the destination service at the application server  108 . The web zone may also include a database for authenticating access to a software application for telephony traffic processed within the SIP zone, for example, a softphone. 
     The clients  104 A through  104 D communicate with the servers  108  through  112  of the datacenter  106  via the network  114 . The network  114  can be or include, for example, the Internet, a local area network (LAN), a wide area network (WAN), a virtual private network (VPN), or another public or private means of electronic computer communication capable of transferring data between a client and one or more servers. In some implementations, a client can connect to the network  114  via a communal connection point, link, or path, or using a distinct connection point, link, or path. For example, a connection point, link, or path can be wired, wireless, use other communications technologies, or a combination thereof. 
     The network  114 , the datacenter  106 , or another element, or combination of elements, of the system  100  can include network hardware such as routers, switches, other network devices, or combinations thereof. For example, the datacenter  106  can include a load balancer  116  for routing traffic from the network  114  to various servers associated with the datacenter  106 . The load balancer  116  can route, or direct, computing communications traffic, such as signals or messages, to respective elements of the datacenter  106 . 
     For example, the load balancer  116  can operate as a proxy, or reverse proxy, for a service, such as a service provided to one or more remote clients, such as one or more of the clients  104 A through  104 D, by the application server  108 , the telephony server  112 , and/or another server. Routing functions of the load balancer  116  can be configured directly or via a DNS. The load balancer  116  can coordinate requests from remote clients and can simplify client access by masking the internal configuration of the datacenter  106  from the remote clients. 
     In some implementations, the load balancer  116  can operate as a firewall, allowing or preventing communications based on configuration settings. Although the load balancer  116  is depicted in  FIG.  1    as being within the datacenter  106 , in some implementations, the load balancer  116  can instead be located outside of the datacenter  106 , for example, when providing global routing for multiple datacenters. In some implementations, load balancers can be included both within and outside of the datacenter  106 . In some implementations, the load balancer  116  can be omitted. 
       FIG.  2    is a block diagram of an example internal configuration of a computing device  200  of an electronic computing and communications system. In one configuration, the computing device  200  may implement one or more of the client  104 , the application server  108 , the database server  110 , or the telephony server  112  of the system  100  shown in  FIG.  1   . 
     The computing device  200  includes components or units, such as a processor  202 , a memory  204 , a bus  206 , a power source  208 , peripherals  210 , a user interface  212 , a network interface  214 , other suitable components, or a combination thereof. One or more of the memory  204 , the power source  208 , the peripherals  210 , the user interface  212 , or the network interface  214  can communicate with the processor  202  via the bus  206 . 
     The processor  202  is a central processing unit, such as a microprocessor, and can include single or multiple processors having single or multiple processing cores. Alternatively, the processor  202  can include another type of device, or multiple devices, configured for manipulating or processing information. For example, the processor  202  can include multiple processors interconnected in one or more manners, including hardwired or networked. The operations of the processor  202  can be distributed across multiple devices or units that can be coupled directly or across a local area or other suitable type of network. The processor  202  can include a cache, or cache memory, for local storage of operating data or instructions. 
     The memory  204  includes one or more memory components, which may each be volatile memory or non-volatile memory. For example, the volatile memory can be random access memory (RAM) (e.g., a DRAM module, such as DDR SDRAM). In another example, the non-volatile memory of the memory  204  can be a disk drive, a solid state drive, flash memory, or phase-change memory. In some implementations, the memory  204  can be distributed across multiple devices. For example, the memory  204  can include network-based memory or memory in multiple clients or servers performing the operations of those multiple devices. 
     The memory  204  can include data for immediate access by the processor  202 . For example, the memory  204  can include executable instructions  216 , application data  218 , and an operating system  220 . The executable instructions  216  can include one or more application programs, which can be loaded or copied, in whole or in part, from non-volatile memory to volatile memory to be executed by the processor  202 . For example, the executable instructions  216  can include instructions for performing some or all of the techniques of this disclosure. The application data  218  can include user data, database data (e.g., database catalogs or dictionaries), or the like. In some implementations, the application data  218  can include functional programs, such as a web browser, a web server, a database server, another program, or a combination thereof. The operating system  220  can be, for example, Microsoft Windows®, Mac OS X®, or Linux®; an operating system for a mobile device, such as a smartphone or tablet device; or an operating system for a non-mobile device, such as a mainframe computer. 
     The power source  208  provides power to the computing device  200 . For example, the power source  208  can be an interface to an external power distribution system. In another example, the power source  208  can be a battery, such as where the computing device  200  is a mobile device or is otherwise configured to operate independently of an external power distribution system. In some implementations, the computing device  200  may include or otherwise use multiple power sources. In some such implementations, the power source  208  can be a backup battery. 
     The peripherals  210  includes one or more sensors, detectors, or other devices configured for monitoring the computing device  200  or the environment around the computing device  200 . For example, the peripherals  210  can include a geolocation component, such as a global positioning system location unit. In another example, the peripherals can include a temperature sensor for measuring temperatures of components of the computing device  200 , such as the processor  202 . In some implementations, the computing device  200  can omit the peripherals  210 . 
     The user interface  212  includes one or more input interfaces and/or output interfaces. An input interface may, for example, be a positional input device, such as a mouse, touchpad, touchscreen, or the like; a keyboard; or another suitable human or machine interface device. An output interface may, for example, be a display, such as a liquid crystal display, a cathode-ray tube, a light emitting diode display, or other suitable display. 
     The network interface  214  provides a connection or link to a network (e.g., the network  114  shown in  FIG.  1   ). The network interface  214  can be a wired network interface or a wireless network interface. The computing device  200  can communicate with other devices via the network interface  214  using one or more network protocols, such as using Ethernet, transmission control protocol (TCP), internet protocol (IP), power line communication, an IEEE  802 .X protocol (e.g., Wi-Fi, Bluetooth, or ZigBee), infrared, visible light, general packet radio service (GPRS), global system for mobile communications (GSM), code-division multiple access (CDMA), Z-Wave, another protocol, or a combination thereof. 
       FIG.  3    is a block diagram of an example of a software platform  300  implemented by an electronic computing and communications system, for example, the system  100  shown in  FIG.  1   . The software platform  300  is a UCaaS platform accessible by clients of a customer of a UCaaS platform provider, for example, the clients  104 A through  104 B of the customer  102 A or the clients  104 C through  104 D of the customer  102 B shown in  FIG.  1   . The software platform  300  may be a multi-tenant platform instantiated using one or more servers at one or more datacenters including, for example, the application server  108 , the database server  110 , and the telephony server  112  of the datacenter  106  shown in  FIG.  1   . 
     The software platform  300  includes software services accessible using one or more clients. For example, a customer  302  as shown includes four clients - a desk phone  304 , a computer  306 , a mobile device  308 , and a shared device  310 . The desk phone  304  is a desktop unit configured to at least send and receive calls and includes an input device for receiving a telephone number or extension to dial to and an output device for outputting audio and/or video for a call in progress. The computer  306  is a desktop, laptop, or tablet computer including an input device for receiving some form of user input and an output device for outputting information in an audio and/or visual format. The mobile device  308  is a smartphone, wearable device, or other mobile computing aspect including an input device for receiving some form of user input and an output device for outputting information in an audio and/or visual format. The desk phone  304 , the computer  306 , and the mobile device  308  may generally be considered personal devices configured for use by a single user. The shared device  310  is a desk phone, a computer, a mobile device, or a different device which may instead be configured for use by multiple specified or unspecified users. 
     Each of the clients  304  through  310  includes or runs on a computing device configured to access at least a portion of the software platform  300 . In some implementations, the customer  302  may include additional clients not shown. For example, the customer  302  may include multiple clients of one or more client types (e.g., multiple desk phones or multiple computers) and/or one or more clients of a client type not shown in  FIG.  3    (e.g., wearable devices or televisions other than as shared devices). For example, the customer  302  may have tens or hundreds of desk phones, computers, mobile devices, and/or shared devices. 
     The software services of the software platform  300  generally relate to communications tools, but are in no way limited in scope. As shown, the software services of the software platform  300  include telephony software  312 , conferencing software  314 , messaging software  316 , and other software  318 . Some or all of the software  312  through  318  uses customer configurations  320  specific to the customer  302 . The customer configurations  320  may, for example, be data stored within a database or other data store at a database server, such as the database server  110  shown in  FIG.  1   . 
     The telephony software  312  enables telephony traffic between ones of the clients  304  through  310  and other telephony-enabled devices, which may be other ones of the clients  304  through  310 , other VOIP-enabled clients of the customer  302 , non-VOIP-enabled devices of the customer  302 , VOIP-enabled clients of another customer, non-VOIP-enabled devices of another customer, or other VOIP-enabled clients or non-VOIP-enabled devices. Calls sent or received using the telephony software  312  may, for example, be sent or received using the desk phone  304 , a softphone running on the computer  306 , a mobile application running on the mobile device  308 , or using the shared device  310  that includes telephony features. 
     The telephony software  312  further enables phones that do not include a client application to connect to other software services of the software platform  300 . For example, the telephony software  312  may receive and process calls from phones not associated with the customer  302  to route that telephony traffic to one or more of the conferencing software  314 , the messaging software  316 , or the other software  318 . 
     The conferencing software  314  enables audio, video, and/or other forms of conferences between multiple participants, such as to facilitate a conference between those participants. In some cases, the participants may all be physically present within a single location, for example, a conference room, in which the conferencing software  314  may facilitate a conference between only those participants and using one or more clients within the conference room. In some cases, one or more participants may be physically present within a single location and one or more other participants may be remote, in which the conferencing software  314  may facilitate a conference between all of those participants using one or more clients within the conference room and one or more remote clients. In some cases, the participants may all be remote, in which the conferencing software  314  may facilitate a conference between the participants using different clients for the participants. The conferencing software  314  can include functionality for hosting, presenting scheduling, joining, or otherwise participating in a conference. The conferencing software  314  may further include functionality for recording some or all of a conference and/or documenting a transcript for the conference. 
     The messaging software  316  enables instant messaging, unified messaging, and other types of messaging communications between multiple devices, such as to facilitate a chat or other virtual conversation between users of those devices. The unified messaging functionality of the messaging software  316  may, for example, refer to email messaging which includes a voicemail transcription service delivered in email format. 
     The other software  318  enables other functionality of the software platform  300 . Examples of the other software  318  include, but are not limited to, device management software, resource provisioning and deployment software, administrative software, and third party integration software. In one particular example, the other software  318  can include a communication request merging engine. 
     The communication request merging engine, when executed, causes a communication server to detect a first communication request from a first caller device to a second caller device. The communication server detects second communication request from the second caller device to the first caller device. The first communication request and the second communication request both occur within a threshold time period (e.g., 15 seconds or 35 seconds). The communication server establishes, without additional input from the first caller device and the second caller device, an active session in response to the first communication request. The active session is established between the first caller device and the second caller device. The communication server dismisses the second communication request. 
     The software  312  through  318  may be implemented using one or more servers, for example, of a datacenter such as the datacenter  106  shown in  FIG.  1   . For example, one or more of the software  312  through  318  may be implemented using an application server, a database server, and/or a telephony server, such as the servers  108  through  112  shown in  FIG.  1   . In another example, one or more of the software  312  through  318  may be implemented using servers not shown in  FIG.  1   , for example, a meeting server, a web server, or another server. In yet another example, one or more of the software  312  through  318  may be implemented using one or more of the servers  108  through  112  and one or more other servers. The software  312  through  318  may be implemented by different servers or by the same server. 
     Features of the software services of the software platform  300  may be integrated with one another to provide a unified experience for users. For example, the messaging software  316  may include a user interface element configured to initiate a call with another user of the customer  302 . In another example, the telephony software  312  may include functionality for elevating a telephone call to a conference. In yet another example, the conferencing software  314  may include functionality for sending and receiving instant messages between participants and/or other users of the customer  302 . In yet another example, the conferencing software  314  may include functionality for file sharing between participants and/or other users of the customer  302 . In some implementations, some or all of the software  312  through  318  may be combined into a single software application run on clients of the customer, such as one or more of the clients  304  through  310 . 
       FIG.  4    illustrates an example communication system  400  in which handling multiple communication requests may be implemented. As shown, the communication system includes caller devices  402  and  404  and a communication server  406 . The caller devices  402  and  404  may correspond to clients  104 A,  104 B,  104 C or  104 D. The communication server  406  may correspond to the datacenter  106 . The communication server  406  includes one or more proxy servers  408  and  410 , including a proxy server  408  associated with the caller device  402  and a proxy server  410  associated with the caller device  404 . Each of the proxy servers  408  and  410  may correspond to the telephony server  112 . The communication server  406  may also, in some cases, include other devices. Each of the caller devices  402  and  404  and the proxy servers  408  and  410  may include all or a portion of the components of the computing device  200 . The caller devices  402  and  404  may be connected with the communication server  406  via one or more networks. The one or more networks may include one or more of the Internet, an intranet, a local area network, a wide area network, wired network, a wireless network, a cellular network, a Wi- FiⓇ network, a VPN, or other networks. 
     The caller devices  402  and  404  may include any devices capable of processing audio or video calls. For example, each caller device  402  and  404  may include one or more of a mobile phone, a tablet computer, a smartwatch, a laptop computer, a desktop computer, a computing device running a softphone application or a VOIP phone. Each caller device  402  and  404  may be capable of placing, receiving or joining one or more of voice calls, video calls, audio conferences, and video conferences. Each caller device  402  and  404  may be registered with a proxy server  408  and  410 , respectively. The proxy server  408  accepts outgoing communication requests from the associated caller device  402  and directs incoming communication requests to the associated caller device  402 . Similarly, the proxy server  410  accepts outgoing communication requests from the associated caller device  404  and directs incoming communication requests to the associated caller device  404 . The proxy server(s)  408 ,  410  may be coupled with caller device(s)  402 ,  404  based on geographic location or connection type (e.g., wired, Wi-FiⓇ or cellular). While two caller devices  402 ,  404  and two proxy servers  408 ,  410  are illustrated, the technology disclosed herein may be implemented with other numbers of caller devices and proxy servers. Furthermore, while  FIG.  4    illustrates a one-to-one coupling of proxy servers to caller devices, in some implementations, a single proxy server may be coupled with multiple caller devices. 
     According to some implementations, the communication server  406  detects a first communication request from the caller device  402  to the caller device  404 . The communication server  406  detects a second communication request from the caller device  404  to the caller device  402 . The first communication request and the second communication request both occur within a threshold time period (e.g. 40 seconds). For example, both the first communication request and the second communication request may be pending at least partially simultaneously. A communication request may be pending if it is already placed but not yet accepted (e.g., by answering a traditional telephone call), cancelled (e.g., the user who placed the communication request cancels it) or sent to a voice or video mailbox. The communication server establishes, without additional input from the caller device  402  and the caller device  404 , an active session in response to the first communication request. The active session is established between the caller device  402  and the caller device  404 . The communication server  406  dismisses the second communication request. More details of examples of activity of the communication server  406  are described below in conjunction with  FIGS.  5 - 7   . 
     Some implementations log that both caller devices  402  and  404  attempted to initiate the call. Such logging may be important for compliance reasons (e.g., all calls initiated by a customer service center are to be recorded) or for individual policy reasons (e.g., one of the caller devices  402  or  404  may have settings that automatically record outgoing calls but not incoming calls). Unless there is a conflict between settings, the outgoing call settings of both caller devices  402  and  404  may be applied to the active session. 
       FIG.  5    is a data flow diagram of an example of a sequence  500  of operations for handling multiple communication requests. As shown, the sequence  500  is implemented using caller device  402 , caller device  404 , and communication server  406 . 
     At block  502 , the caller device  402  initiates a first call with the caller device  404 . The initiation of the first call is communicated to communication server  406 . For example, a user of the caller device  402  may dial a telephone number associated with caller device  404  or place a request to communicate with an account identifier associated with caller device  404  in an audio or video communication application. 
     At block  504 , the caller device  404  initiates a second call with the caller device  402 , for example, using similar techniques to those described in conjunction with block  502 . The initiation of the second call is communicated to communication server  406 . In some implementations, the initiation of the first call (of block  502 ) is detected, at the communication server  406 , before the initiation of the second call (of block  504 ). The caller device  404  may initiate the second call with the caller device  402  using a different technique than the caller device  402  uses to initiate the first call (for example, the caller device  402  may initiate the first call using a telephone number that is coordinated via the PSTN while the caller device  404  may initiate the second call using an email address). 
     At block  506 , the communication server  406  starts an active session in response to the initiation of the first call. The communication server  406  notifies the caller device  402  that the active session is starting and joins the caller device  402  to the active session. The active session is configured based on a configuration (e.g., recording configuration, time limit configuration, audio and video accessibility configuration) associated with the caller device  402 . A recording configuration may include automatically recording an active session to the local memory of a caller device or to a network-based memory location. A time limit configuration may include a configuration that terminates an active session a predetermined amount of time (e.g., 30 minutes or 45 minutes) after the active session begins. An audio and video accessibility configuration may include whether participant(s) in the active session are permitted to transmit audio or video (e.g., whether each participant’s camera or microphone is turned on or off). 
     At block  508 , the communication server  406  verifies that the caller device  404  is still initiating the second call. For example, the second call might not have been answered yet (by the caller device  402 ), and the caller device  404  might not have cancelled the call initiation request. 
     At block  510 , in response to verifying that the caller device  404  is still initiating the second call, the communication server  406  joins the caller device  404  to the active session. The caller device  404  may be joined to the active session without additional input from either the caller device  402  or the caller device  404 . For example, the user of the caller device  404  might not have to affirmatively answer the call from the caller device  402  in order to be joined into the active session. In some cases, if additional device(s) (in addition to the caller device  402  and the caller device  404 ) are present in the active session, the communication server  406  notifies the caller device  404  of the presence of the additional device(s) in the active session. 
     At block  512 , the communication server  406  conducts the active session. The active session includes at least the caller device  402  and the caller device  404 . 
     Some implementations may be performed in conjunction with an audio or video calling application, where the caller devices  402 ,  404  have the audio or video calling application installed thereon, and the communication server  406  is associated with the audio or video calling application. Some embodiments may be implemented using a telephone network, where the communication server  406  is a server associated with a telephone network and the caller devices  402 ,  404  are telephones or computing devices having an assigned telephone number or telephone calling application running thereon. 
     Some implementations relate to SIP. Some implementations include adapting SIP for a situation when two caller devices call each other within a threshold time period of one another. 
       FIG.  6    is a data flow diagram of an example sequence  600  of operations for modification of SIP for handling multiple communication requests. As shown, the sequence  600  uses the caller device  402 , the caller device  404 , and the communication server  406 . 
     As shown, the caller device  402  sends an invite  602  (for a first call with the caller device  404 ) to the communication server  406 . Within a threshold time (e.g., 5 seconds or 30 seconds), the caller device  404  sends an invite  604  (for a second call with the caller device  402 ) to the communication server  406 . 
     In response to the invite  602 , the communication server  406  forwards the invite  602  and a ringing  606  command to the caller device  404 . The communication server  406  sends a trying  608  message to the caller device  402  so the caller device  402  stops retransmission of the invite  602 . 
     Similarly, in response to the invite  604 , the communication server  406  forwards the invite  604  and a ringing  610  command to the caller device  402 . The communication server  406  sends a trying  612  message to the caller device  404  so the caller device  404  stops retransmission of the invite  604 . 
     The communication server  406  notifies caller device  402  of ringing  606  at the caller device  404  at approximately the same time (e.g., within 10 seconds or 20 seconds) as notifying the caller device  404  of ringing  610  at the caller device  402 . 
     To prevent confusion (e.g., by people) from ensuing when the two call initiations are accepted in parallel, the communication server  406  automatically (e.g., without additional input from the caller device  402  or the caller device  404 ) connects  612  the call based on the invite  602  and dismisses  614  the call based on the invite  604 . The communication server  406  transmits, to the caller device  402  and the caller device  404 , the connect  612  signal and the dismiss  614  signal. 
     The call based on the invite  602  then proceeds. Caller device  402  and caller device  404  communicate using Real-time Transport Protocol (RTP) or RTP Control Protocol (RTCP)  616  until one of the caller device  402  or the caller device  404  decides to end the call. As shown, the caller device  402  sends a bye  618  signal ending the call. In response, the caller device  404  sends an ok  620  signal acknowledging the end of the call. In alternative implementations, the caller device  404  could send the bye signal and the caller device  402  could send the ok signal. 
     Some implementations relate to determining, from among two (or more) caller devices that call each other within a threshold time period, which caller device will be the first caller device  402  and which caller device will be the second caller device  404 . The first caller device  402  may be said to have ownership of the active session. In some implementations, ownership of the active session is assigned to the first caller device  402  and configuration settings of the active session are set based on settings of an account associated with the first caller device  402 . The configuration settings may include, for example, recording settings or time-limit settings. 
     In some implementations, the first caller device  402  is identified, by the communication server  406 , based on the invite  602  from the first caller device  402  reaching the communication server  406  before the invite  604  from the second caller device  404 . 
     In some implementations, the first communication request from the first caller device  402  (which is to receive ownership of the active session) is identified, from a set comprising the first communication request from the first caller device  402  and the second communication request from the second caller device  404 , based on at least one of a set of factors. The set of factors may include a timing of communication requests in the set. The set of factors may include a status (e.g., very important person (VIP), regulatory) associated with devices initiating the communication requests in the set, with the highest status person on the call getting ownership of the call. The status may be useful for customer service needs of the telephony service provider. Regulatory teams may have complex recording and storage settings associated with their calls for legal reasons, and it is good customer service for the telephony service provider to keep VIPs (e.g., president or chief executive of a company) pleased by enforcing their call settings whenever it may be desirable to the VIPs. The set of factors may include a signal quality associated with the devices initiating the communication requests in the set. For example, if one device has a strong network signal and another device has a weak network signal, the device with the strong signal may be assigned ownership of the communication request. The set of factors may include a complexity of settings (e.g., if one device uses default settings and another device has unique time limit, recording, and audio volume limit settings, the settings of the other device may be used, as the user of the other device is likely to have carefully created his/her settings and to value the settings) associated with the devices initiating the communication requests in the set. The set of factors may include an indication that a user of one of the devices initiating the communication requests in the set created a calendar event associated with the active session. For example, the caller who created the calendar invite for the active session may be assigned ownership of the active session. Information identifying the caller who created the calendar invite may, for example, be or include metadata associated with a calendar of one or both of the callers using the first caller device  402  and the second caller device  404 . The set of factors may include a device type of the devices initiating the communication requests in the set. For example, if a user of a desktop computer is initiating an active session with a user of a mobile phone using the techniques described herein, the setting associated with the user of the desktop computer may be used. 
       FIGS.  4 - 6    illustrate two caller devices  402 ,  404  attempting to connect to one another by placing calls to one another within a threshold time period of each other. However, in some implementations, more than two caller devices (e.g., three caller devices, four caller devices, five caller devices, or more) may attempt to connect to one another within a threshold time period of each other. 
       FIG.  7    illustrates a first example system  700  with three caller devices calling one another within a threshold time period. As shown in  FIG.  7   , caller device  702  calls caller device  704 , caller device  704  calls caller device  706 , and caller device  706  calls caller device  702 , all within a threshold time period of each other. In response, a three-way active session between caller devices  702 ,  704 ,  706  may be created, and one of the caller devices  702 ,  704 ,  706  may be assigned ownership of the active session using the techniques described above. All of the caller devices  702 ,  704 , and  706  may be informed of the other caller devices present on the call to protect privacy and avoid surprises. For example, when caller device  702  calls caller device  704 , the user of caller device  702  might not expect the user of caller device  706  to be present on the call (at least until the caller device  706  is added to the call). 
       FIG.  8    illustrates a second example system  800  with three caller devices calling one another within a threshold time period. As shown in  FIG.  8   , caller device  802  calls caller device  804 , caller device  804  calls caller device  802 , and caller device  806  calls caller device  802 , all within a threshold time period of each other. In response, in some examples, a three-way active session may be set up between caller devices  802 ,  804 , and  806 , as described in conjunction with  FIG.  7   . This might be desirable, for example, if there are other indicia (e.g., text messages, email messages or a calendar invite) that the users of the caller devices  802 ,  804 , and  806  wanted to communicate with one another in a three-way active session. 
     However, in some situations, the users of the caller devices  802  and  804  want to communicate with one another without the user of the caller device  806 . For example, the users of the caller devices  802  and  804  may be coworkers working on a project together, while the user of the caller device  806  might be a telemarketer or a personal friend of the user of the caller device  802 , who should not be present during the call between caller devices  802  and  804 . Thus, if indicia that the users of the caller devices  802 ,  804 , and  806  wanted to communicate with one another in a three-way active session are not present, a two-way active session may be created between the caller devices  802  and  804  may be created using the techniques described herein. The caller device  802  might also be informed of the incoming call from caller device  806  (and, upon acceptance of the call from caller device  806 , could have the option to merge the calls between caller devices  802 ,  804  and caller devices  802 ,  806 ) using call waiting functionality. Alternatively, the caller device  806  might be informed that the caller device  802  is unavailable or provided the option to leave a message in a voice mailbox associated with the caller device  802 . 
       FIG.  9    illustrates an example system  900  in which call merging and ownership assignment may be implemented. As shown, the system  900  includes caller devices  902  and  904  and a communication server  906 . As illustrated in  FIG.  9   , caller device  902  and caller device  904  call each other, via the communication server  906 , within a threshold time period of one another. At block  908 , the communication server  906  assigns ownership of the active session between caller devices  902  and  904 . As shown, the communication server  906  stores a data structure  910  that is used to assign ownership of the active session. The data structure  910  stores a set of caller accounts. For each caller account, the data structure  910  stores a Boolean VIP status and an indication of a team associated with the caller account. (In alternative implementations, the VIP status might have a value other than Boolean, for example, a number indicating rank or a military (or other) rank such as “Sergeant,” “Corporal,” “Private,” and other military ranks.) The ownership of the active session, at block  908 , may be assigned based on data of the caller accounts (e.g., VIP status or team membership) stored in the data structure  910  that is associated with the caller accounts of the caller devices  902  and  904 . 
     To further describe some implementations in greater detail, reference is next made to examples of techniques which may be performed by or using a communication server (e.g., communication server  406 ) in handling multiple communication requests.  FIG.  10    is a flowchart of an example of a technique  1000  for handling multiple communication requests. The technique  1000  can be executed using computing devices, such as the systems, hardware, and software described with respect to  FIGS.  1 - 9   . The technique  900  can be performed, for example, by executing a machine-readable program or other computer-executable instructions, such as routines, instructions, programs, or other code. The steps, or operations, of the technique  1000  or another technique, method, process, or algorithm described in connection with the implementations disclosed herein can be implemented directly in hardware, firmware, software executed by hardware, circuitry, or a combination thereof. 
     For simplicity of explanation, the technique  1000  is depicted and described herein as a series of steps or operations. However, the steps or operations in accordance with this disclosure can occur in various orders and/or concurrently. Additionally, other steps or operations not presented and described herein may be used. Furthermore, not all illustrated steps or operations may be required to implement a technique in accordance with the disclosed subject matter. 
     At block  1002 , a communication server (e.g., communication server  406 ) detects a first communication request from a first caller device (e.g., caller device  402 ) to a second caller device (e.g., caller device  404 ). For example, the first caller device may dial a telephone number associated with the second caller device. Alternatively, a user of the first caller device may enter a voice or video communication request to the second caller device via a contact list at the first caller device. 
     At block  1004 , the communication server detects a second communication request from the second caller device to the first caller device. The first communication request and the second communication request both occur within a threshold time period. For example, the second caller device may dial a telephone number associated with the first caller device. Alternatively, a user of the second caller device may enter a voice or video communication request to the first caller device via a contact list at the second caller device. 
     At block  1006 , the communication server determines that the first communication request, rather than the second communication request, should be used to establish the active session between the first caller device and the second caller device. This determination may be made based on an initiation time of the first communication request preceding an initiation time of the second communication request. This determination may be made based on at least one of: a timing of communication requests in a set including the first communication request and the second communication request, a status associated with devices initiating the communication requests in the set, a signal quality associated with the devices initiating the communication requests in the set, a complexity of settings associated with the devices initiating the communication requests in the set, an indication that a user of one of the devices initiating the communication requests in the set created a calendar event associated with the active session, or a device type of the devices initiating the communication requests in the set. 
     At block  1008 , the communication server establishes the active session in response to the first communication request. The active session is established between the first caller device and the second caller device. The active session is established without additional input from the first caller device and the second caller device. The active session may include a voice call, a video call, an audio conference or a video conference. 
     At block  1010 , the communication server dismisses the second communication request. For example, the communication server sends a “dismiss” message to the second caller device in response to the second communication request. In response to the “dismiss” message, the second caller device might stop attempting to initiate an active session in response to the second caller request. According to some implementations, the communication server dismisses the second communication request in response to determining, at the communication server, that the second communication request is still pending. 
     According to some implementations, the communication server includes one or more proxy servers (e.g., proxy server  408  and proxy server  410 ). 
     According to some implementations, the active session is configured according to configuration setting associated with the first caller device. The configuration includes recording settings or time-limit settings. 
     According to some implementations, the communication server determines, upon the second caller device joining the active session, that at least one third caller device is present in the active session. The communication server transmits, to the second caller device, a notification indicating the presence of the third caller device(s). 
     According to some implementations, the first communication request is detected, by the communication server, before the second communication request. 
     According to some implementations, to establish the active session, the communication server notifies the first caller device of acceptance of the first communication request. The communication server merges the second communication request into the active session. 
       FIG.  11    is a flowchart of an example of a technique  1100  for handling multiple communication requests with three or more parties. The technique  1000  can be executed using computing devices, such as the systems, hardware, and software described with respect to  FIGS.  1 - 9   . The technique  1100  can be performed, for example, by executing a machine-readable program or other computer-executable instructions, such as routines, instructions, programs, or other code. The steps, or operations, of the technique  1100  or another technique, method, process, or algorithm described in connection with the implementations disclosed herein can be implemented directly in hardware, firmware, software executed by hardware, circuitry, or a combination thereof. 
     For simplicity of explanation, the technique  1100  is depicted and described herein as a series of steps or operations. However, the steps or operations in accordance with this disclosure can occur in various orders and/or concurrently. Additionally, other steps or operations not presented and described herein may be used. Furthermore, not all illustrated steps or operations may be required to implement a technique in accordance with the disclosed subject matter. 
     At block  1102 , a communication server detects communication requests between multiple caller devices in a set of caller devices, for example, as shown in  FIGS.  7 - 8   . As shown in  FIG.  7   , caller device  702  calls caller device  704 , caller device  704  calls caller device  706 , and caller device  706  call caller device  702 . As shown in  FIG.  8   , caller device  802  calls caller device  804 , caller device  804  calls caller device  802 , and caller device  806  calls caller device  802 . In some embodiments, two or more of the caller devices in the set might already be communicating with one another when the communication requests are received. For example, Device A might call into a conference call including Device B and Device C, while Device C calls Device A to add Device A into the conference call. 
     At block  1104 , the communication server selects a subset of the set of caller devices to connect. The subset may include all or a portion of the caller devices in the set. For example, as shown in  FIG.  7   , each and every one of the devices in the set of caller devices  702 ,  704 , and  706  may be connected. As shown in  FIG.  8   , caller devices  802  and  804  may be connected. However, caller device  806  might not be connected unless one of the caller devices  802  and  804  attempts to add caller device  806  to the active session between caller devices  802  and  804 . 
     At block  1106 , the communication server selects a communication request associated with the subset that is to be used to establish an active session. The communication request that is selected may be the one that was initiated earliest-in-time. The communication request may be selected based on at least one of: a timing of communication requests, a status associated with devices initiating the communication requests, a signal quality associated with the devices initiating the communication requests, a complexity of settings associated with the devices initiating the communication requests, an indication that a user of one of the devices initiating the communication requests in the set created a calendar event associated with the active session, or a device type of the devices initiating the communication requests in the set. 
     At block  1108 , the communication server establishes an active session including the subset of caller devices in response to the selected communication request. The settings of the selected communication request are used as the setting for the active session. For example, recording settings (e.g., whether the active session is recorded to a network-based storage unit or a local memory of a caller device in the active session), time limit settings (e.g., whether the call is automatically terminated after a predetermined time period), and the like may be used. 
     At block  1110 , the communication server notifies caller devices in the active session of the presence of other caller devices in the active session. This prevents users of the caller devices from being surprised that devices that they did not call are present in the active session. The notification may be provided in audio form or in a visual display. For example, the communication server may play an audio into the active session stating an identifier (e.g., a telephone number, an email address or a user identifier) of all or a portion of the devices present in the active session. 
     Some implementations are described below as numbered examples (Example 1, 2, 3, etc.). These examples are provided as exampled only and do not limit the disclosed technology. 
     Example 1 is a method comprising: detecting a first communication request from a first caller device to a second caller device; detecting a second communication request from the second caller device to the first caller device, wherein the first communication request and the second communication request both occur within a threshold time period; establishing, without additional input from the first caller device and the second caller device, an active session in response to the first communication request, wherein the active session is established between the first caller device and the second caller device; and dismissing the second communication request. 
     In Example 2, the subject matter of Example 1 includes, wherein the first communication request and the second communication request are detected at a communication server comprising one or more proxy servers. 
     In Example 3, the subject matter of Examples 1-2 includes, wherein the active session is configured according to a configuration setting associated with the first caller device, and wherein the configuration setting comprises recording settings or time-limit settings. 
     In Example 4, the subject matter of Examples 1-3 includes, wherein the active session comprises at least one of a voice call, a video call, an audio conference or a video conference. 
     In Example 5, the subject matter of Examples 1-4 includes, determining, based on the second caller device joining the active session, that a third caller device is present in the active session; and transmitting, to the second caller device, a notification indicating the presence of the third caller device. 
     In Example 6, the subject matter of Examples 1-5 includes, wherein the first communication request is detected before the second communication request. 
     In Example 7, the subject matter of Examples 1-6 includes, wherein the first communication request is identified, from a set of communication requests comprising the first communication request and the second communication request, based on at least one of: a timing of communication requests in the set, a status associated with each device initiating the communication requests in the set, a signal quality associated with the devices initiating the communication requests in the set, a complexity of settings associated with the devices initiating the communication requests in the set, an indication that a user of one of the devices initiating the communication requests in the set created a calendar event associated with the active session, or a device type of the devices initiating the communication requests in the set. 
     In Example 8, the subject matter of Examples 1-7 includes, wherein the active session is established by: notifying, by the communication server, the first caller device of acceptance of the first communication request; and merging, by the communication server, the second communication request into the active session. 
     In Example 9, the subject matter of Examples 1-8 includes, wherein the second communication request is dismissed in response to determining, at the communication server, that the second communication request is still attempting to connect. 
     In Example 10, the subject matter of Examples 1-9 includes, logging that the first caller device and the second caller device attempted to initiate the active session; and applying configuration settings associated with both the first caller device and the second caller device to the active session. 
     Example 11 is an apparatus comprising: a memory; and a processor configured to execute instructions stored in the memory to: detect a first communication request from a first caller device to a second caller device; detect a second communication request from the second caller device to the first caller device, wherein the first communication request and the second communication request both occur within a threshold time period; establish, without additional input from the first caller device and the second caller device, an active session in response to the first communication request, wherein the active session is established between the first caller device and the second caller device; and dismiss the second communication request. 
     In Example 12, the subject matter of Example 11 includes, wherein the active session is configured according to a configuration setting associated with the first caller device, and wherein the configuration setting comprises recording settings or time-limit settings. 
     In Example 13, the subject matter of Examples 11-12 includes, wherein the active session comprises at least one of a voice call, a video call, an audio conference or a video conference. 
     In Example 14, the subject matter of Examples 11-13 includes, wherein the processor is further configured to execute instructions stored in the memory to: determine, based on the second caller device joining the active session, that a third caller device is present in the active session; and transmit, to the second caller device, a notification indicating the presence of the third caller device. 
     In Example 15, the subject matter of Examples 11-14 includes, wherein the first communication request is detected before the second communication request. 
     In Example 16, the subject matter of Examples 11-15 includes, wherein the first communication request is identified, from a set of communication requests comprising the first communication request and the second communication request, based on at least one of: a timing of communication requests in the set, a status associated with each device initiating the communication requests in the set, a signal quality associated with the devices initiating the communication requests in the set, a complexity of settings associated with the devices initiating the communication requests in the set, an indication that a user of one of the devices initiating the communication requests in the set created a calendar event associated with the active session, or a device type of the devices initiating the communication requests in the set. 
     In Example 17, the subject matter of Examples 11-16 includes, wherein the active session is established by: notifying, by the communication server, the first caller device of acceptance of the first communication request; and merging, by the communication server, the second communication request into the active session. 
     Example 18 is a computer-readable medium storing instructions operable to cause one or more processors to perform operations comprising: detecting a first communication request from a first caller device to a second caller device; detecting a second communication request from the second caller device to the first caller device, wherein the first communication request and the second communication request both occur within a threshold time period; establishing, without additional input from the first caller device and the second caller device, an active session in response to the first communication request, wherein the active session is established between the first caller device and the second caller device; and dismiss the second communication request. 
     In Example 19, the subject matter of Example 18 includes, wherein the first communication request and the second communication request are detected at a communication server comprising one or more proxy servers. 
     In Example 20, the subject matter of Examples 18-19 includes, wherein the active session is configured according to a configuration setting associated with the first caller device, and wherein the configuration setting comprises recording settings or time-limit settings. 
     Example 21 is at least one machine-readable medium including instructions that, when executed by processing circuitry, cause the processing circuitry to perform operations to implement of any of Examples 1-20. 
     Example 22 is an apparatus comprising means to implement of any of Examples 1-20. 
     Example 23 is a system to implement of any of Examples 1-20. 
     Example 24 is a method to implement of any of Examples 1-20. 
     The implementations of this disclosure can be described in terms of functional block components and various processing operations. Such functional block components can be realized by a number of hardware or software components that perform the specified functions. For example, the disclosed implementations can employ various integrated circuit components (e.g., memory elements, processing elements, logic elements, and look-up tables), which can carry out a variety of functions under the control of one or more microprocessors or other control devices. Similarly, where the elements of the disclosed implementations are implemented using software programming or software elements, the systems and techniques can be implemented with a programming or scripting language, such as C, C++, Java, JavaScript, assembler, or the like, with the various algorithms being implemented with a combination of data structures, objects, processes, routines, or other programming elements. 
     Functional aspects can be implemented in algorithms that execute on one or more processors. Furthermore, the implementations of the systems and techniques disclosed herein could employ a number of conventional techniques for electronics configuration, signal processing or control, and data processing. The words “mechanism” and “component” are used broadly and are not limited to mechanical or physical implementations, but can include software routines in conjunction with processors, etc. Likewise, the terms “system” or “tool” as used herein and in the figures, but in any event based on their context, may be understood as corresponding to a functional unit implemented using software, hardware (e.g., an integrated circuit, such as an ASIC), or a combination of software and hardware. In certain contexts, such systems or mechanisms may be understood to be a processor-implemented software system or processor-implemented software mechanism that is part of or callable by an executable program, which may itself be wholly or partly composed of such linked systems or mechanisms. 
     Implementations or portions of implementations of the above disclosure can take the form of a computer program product accessible from, for example, a computer-usable or computer-readable medium. A computer-usable or computer-readable medium can be a device that can, for example, tangibly contain, store, communicate, or transport a program or data structure for use by or in connection with a processor. The medium can be, for example, an electronic, magnetic, optical, electromagnetic, or semiconductor device. 
     Other suitable mediums are also available. Such computer-usable or computer-readable media can be referred to as non-transitory memory or media, and can include volatile memory or non-volatile memory that can change over time. The quality of memory or media being non-transitory refers to such memory or media storing data for some period of time or otherwise based on device power or a device power cycle. A memory of an apparatus described herein, unless otherwise specified, does not have to be physically contained by the apparatus, but is one that can be accessed remotely by the apparatus, and does not have to be contiguous with other memory that might be physically contained by the apparatus. 
     While the disclosure has been described in connection with certain implementations, it is to be understood that the disclosure is not to be limited to the disclosed implementations but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the scope of the appended claims, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as is permitted under the law.