WO2015047335A1

WO2015047335A1 - Managing multicast transmissions

Info

Publication number: WO2015047335A1
Application number: PCT/US2013/062416
Authority: WO
Inventors: Jorge Arturo SAUMA; John W FLICK; Ashwin Bhalchandra Hegde; James P HICKEY
Original assignee: Hewlett-Packard Development Company, L.P.
Priority date: 2013-09-27
Filing date: 2013-09-27
Publication date: 2015-04-02
Also published as: EP3050328A1; CN105745950A

Abstract

A multicast service request is received at a network access point. The access point creates and stores a record that associates the service with the client device. The access point receives a service announcement from a network device hosting the service requested by the client device, and forwards the service announcement to the client device via unicast transmission.

Description

[0001] Zero-configuration (zeroconf) networking protocols such as the multicast domain name system (mDNS) protocol allow network devices to advertise and discover services offered by the network devices, without using a centralized DNS server. Each network device may send a multicast packet announcing the services, thus allowing client devices to discover the services offered by the network devices,

BRIEF DESCRIPTION OF THE DRAWINGS

[0002] The present application may be more fully appreciated in connection with the following detailed description taken in conjunction with the accompanying drawings, in which like reference characters refer to like parts throughout, and in which:

[0003] FIG. 1 is a block diagram of a network access point for managing multicast transmissions, according to one example;

[0004] FIG, 2 is a block diagram of a network access point for managing multicast transmissions over a network, according to one example;

[0005] FIG. 3 is a flowchart of a method for managing multicast transmissions, according to one example;

[0006] FIG, 4 is a flowchart of a method for managing multicast transmissions, according to another example; and

[0007] FIG. 5 is a block diagram of a multicast transmission manager including a computer- readable medium having instructions for managing multicast transmissions, according to one example,

DETAILED DESCRIPTION

[0008] With the emergence of wireless local area networks (WLANs) and other modem network technologies, users are able to easily connect their devices (e.g., tablets, smartphones, etc) to the network without complicated configurations. Zeroconf is a set of network technologies used together to allow for automated network configuration of devices and services, without the use of central services such as DNS and dynamic host configuration protocol (DHCP). Thus, zeroconf does not require manual operator intervention (e.g., network administrator) or special configuration servers. Zeroconf covers addressing (i.e., IP address configuration), name resolution (e.g., translation between host name and IP address), and service discovery (e.g., printing).

[0009] In service discovery, for example, devices looking for a service send out multicast requests (i.e., multicast query) containing the type of service requested and/or the service attributes. Devices which can fulfill such requests then send a multicast reply (e.g., service announcement). This method of multicast transmission may cause network congestion and increased traffic, especially in special environment like wireless networks. For example, since the multicast traffic must reach all devices connected to the wireless network, the wireless rate of transmission may need to be adjusted to the devices with the slowest data rate, thereby slowing down the whole network.

[0010] Examples disclosed herein provide a solution for managing such multicast transmissions (e.g., queries or services requests). For example, when a network manager (e.g., a network access point) receives a service announcement, the network manager keeps records of the services. Then, when a multicast query is received and based on the records, the query is forwarded to the right client devices via unicast transmission. To illustrate, if a wireless tablet computing device wants to print a document, the tablet device sends a query for printers to an access point to which the tablet is associated/connected. The access point may create a query table that includes a record associating the tablet device with a type of service (e.g., print service). When a response is received from a printing device in the network, the response is forwarded, via unicast transmission, to the tablet. Thus, a layer-2 multicast wireless packet can be converted to a layer-2 unicast wireless traffic, making the transmission more efficient. Because the response is not multicast to other devices that may not need the print service, the efficiency of the network is improved and the network traffic is significantly reduced.

[OOllj In one example, a method for managing multicast transmissions includes receiving, at a network access point, a multicast query from a client device, where the multicast query includes a service request. The method includes creating and storing a record associating the service with the client device. The method also includes receiving a service announcement from a network device hosting the service requested by the client device, and forwarding the service announcement to the client device via unicast transmission.

[0012] In another example, a network access point for managing multicast transmission includes a processor to receive a multicast transmission from a client device, where the multicast transmission includes a service request. The processor is to determine a type of service requested by the client device, create and store a record associating the type of service to the client, and forward the service request to a network device via unicast transmission. The processor is further to receive a service announcement from the network device, where the service announcement includes the type of service requested by the client device, and forward the service announcement to the client device via unicast transmission.

[0013] In another example, a non-transitory computer-readable medium includes instructions that, when executed by a processor of a multicast transmission manager, cause the processor to receive a multicast transmission from a client device, where the multicast transmission includes a service request. The instructions are executable by the processor to analyze the service request to determine a type of service requested by the client device, create and store a record that associates the type of service to the client device, and forward the service request via unicast transmission to a network device known to host the type of service. The instructions are further executable by the processor to receive a response to the service request from tire network device, and to forward the response to the client device via unicast transmission.

[0014] With reference to the figures, FIG. 1 is a block diagram of a network access point for managing multicast transmissions, according to one example. Access point 102 is any network device or computing device that serves and/or provides a plurality of client devices such as client device 104 with access to a network (e.g., wireless local area network

(WLAN), cellular network, ad-hoc network, etc.). For example, access point 102 may be a WLA access point, a router, an ad-hoc device, a station, a router, a network controller, or any other network node. Thus, client device 104 may connect to the network by associating with the access point 102, to transmit and receive data and/or network services.

[0015] Client device 104 may be, for example, a cellular device, a notebook computing device, a tablet computing device, a personal digital assistance (PDA), a desktop PC, a smartphone, or any other computing device that may rely on the access point 102 for network access. Client device 104 may request services from network devices such as network device 106. For example in a zeroconf protocol such as a multicast DNS (mDNS) protocol, client device 104 may request one or more services by sending out a multicast request (or multicast query). Network device 106 may be, for example, a printing device, a scanning device, facsimile device, or any other network device to provide network services to client devices and/or to respond to network requests received from client devices. Thus, for example, network device 106 may be a printer, scanner, a multifunction printer (MFP), an all-in-one (AiO) de vice, a ser v er, or any other device capable of processing requests from client devices.

[0016] Access point 102 may include a processor 1 12. and storage 122. Processor 112. can be one or more central processing units (CPUs), microprocessors, and/or other hardware devices suitable for managing multicast transmissions. Storage 122 represents generally any device or combination of devices configured to store data for use by access point 102. Such data may include a list of client devices such as client device 104, and services requested by the client devices.

[0017] Client device 104 may send a multicast query that includes a service request (e.g., printing service). When the multicast query is received at the access point 102, processor 1 12 can analyze the query to determine the type of service requested by the client device 104. Processor 1 12 creates a record that associates the client device 1 4 with the type of service. The record is stored in the storage device 122. Processor 1 12 forwards the service request to the network device 106 via unicast transmission,

[0018] In certain examples, the multicast query including the service request is a layer-2 multicast packet. In multicast transmission, data packets are delivered to a group of devices in a network simultaneously in a single transmission from a source. However, in unicast transmission, data packets are delivered to a single network destination. Accordingly, in the described examples, the layer-2 packet query packet received from the client device 104 is converted to a layer-2 unicast packet.

[0019] In some examples, the network device 106 is known by the access point 102 to offer the service requested by the client device 104. Thus, the service request may be directed to an appropriate and targeted network device 106 instead of sending the service request to all network devices 106. [0020] Further, in certain examples, the processor 1 12 may set a threshold time for receiving a response from the network device 106. The response to the service may be in the form of a service announcement including the service requested by the client device 104. If the service announcement is received within the threshold time, the access point 102. forwards the service announcement to the client device 104 via unicast transmission. However, if the service announcement is not received within the threshold time, the service announcement is discarded. Because the service announcement is sent via unicast transmission to the client device 104 requesting the service, traffic is reduced in the network.

[0021] FIG. 2 is a block diagram of a network access point for managing multicast transmissions over a network, according to one example. In the example of FIG. 2, access point 202 may communicate with a plurality of client devices 204a-204n over a network 220. Moreover, access point 202 may provide client devices 204a-204n with access to the network. Further, access point 202 may forward service requests received from client devices 204a-204n to one or more of network devices 206a-206n.

[0022] As illustrated in FIG. 2, access point 202 may include a number of modules 221-227. Each of the modules 221-227 may include a series of instructions encoded on a machine- readable storage medium and executable by a processor of the access point 202. In addition or as an alternative, each module may include one or more hardware devices including electronic circuitry for implementing the functionality described below.

[0023] As with access point 102 of FIG. 1, access point 202 may be any network node or device for providing network access to the plurality of client devices 204a-204n and/or for forwarding a multicast query/service request from the client devices 204a-204n to the network devices 206a-206n capable of fulfilling the service request. Thus, access point 202 may include a series of modules 221-227 for receiving a multicast transmission from one or more client devices 204a-204n, forwarding the service request included in the multicast transmission to one or more network devices 206a-206n via unicast transmission, receiving a service announcement from the one or more network devices 206a-2.06n, and forwarding the one or more service announcements to the one or more client devices 204a-204n that request the service via unicast transmission. [0024] Multicast query receiving module 221 may receive a multicast transmission from a client device such as client device 204a, where the multicast transmission includes a service request. For example, the service request can be a printing service.

[0025] Service type determining module 222 may determine a type of service requested by the client device 204a. For example, the multicast transmission may be analyzed to determine the type of service requested by the client device 204a (e.g., a printing service).

[0026] Service record creating module 223 may create and store a record associating the type of service to the client device. For example, a query table or record may be created to keep track of which clien t devices 204a-204n request what services.

[0027] Service request forwarding module 224 may forward the service request to one or more network devices 206a-206n via unicast transmission. For example, the service request may be forwarded to network devices 206a and 206n which may be identified or known to host tire type of service requested by tire client device 206a. Thus, the service request is may not be forwarded via multicast transmission, thereby reducing the network traffic.

[0028] Timing module 2.25 may set a threshold time for receiving a response (e.g., a service announcement) from the network devices 206a and 206b. For example, a predetermined time in the order of a few seconds (e.g., 7 seconds) may be set for receiving a service

announcement from the network devices 206a, 206b, The service announcement may indicate that the network devices 206a, 206n are able to fulfill the service requested by the client device 204a. In some examples, the service announcement may also include information usable by the client device 204a for connecting to and accessing the service at the network device (e.g., network address, location of service, etc.).

[0029] Service announcement receiving module 22.6 may receive a service announcement from the network device 206a and/or 206n. As noted above, the service announcement may- enable the client device to discover the network device.

[0030] Service announcement forwarding module 227 may forward the service

announcement to the client device via unicast transmission. For example, if the service announcement is received within the threshold time, the service announcement is forwarded to the client device 204a via unicast transmission. If the service announcement is received after the threshold time has elapsed, the service announcement may be discarded. Further, the service announcement may also be sent via unicast transmission to another client device, for example client device 204b, that may have previously requested the same service requested by the client device 204a. Accordingly, the service announcement for a particular service may be sent to client devices 204a and 2.04b that have requested the particular service, but not to client devices 204c-204n that have not requested the particular service, based on the record (e.g., a query table) that associates client devices with types of service requested.

[0031] FIG. 3 is a flowchart of a method for managing multicast transmissions, according to one example. Method 300 may be implemented, for example, in the form of executable instructions stored on a non-transitory computer-readable storage medium and/or in the form of electronic circuitry.

[0032] Method 300 includes receiving, at a network access point, a multicast query from a client device, where the multicast query includes a service request, at 310. For example, a printing service request may be sent from a client device to an access point via multicast transmission,

[0033] Method 300 includes creating and storing a record that associates the service with the client device, at 320. For example, the access point may create a record that contains information regarding the identity of a client device and the type of service requested by the client device.

[0034] Method 300 includes receiving a service announcement from a network device that hosts the service requested by the client device, at 330. For example, in response to the service request, a network device may send a service announcement that indicates the availability of the service at the network device. To illustrate, an available network printer may respond to the printing service request.

[0035] Method 300 includes forwarding the service announcement to the client via unicast transmission, at 340. For example, the access point may forward the service announcement to the client device that requested the service via unicast transmission. In some examples, the service request is forwarded via unicast transmission to other client devices that have also requested the same service.

[0036] FIG. 4 is a flowchart of a method for managing multicast transmissions, according to another example. Method 400 may be implemented, for example, in the form of executable instructions stored on a non -transitory computer-readable storage medium and/or in the form of electronic circuitry.

[0037] Method 400 includes receiving, at a network access point, a multicast query from a client device, where the multicast query includes a service request, at 410. For example, a multicast service request may be sent from a client device requesting a service such as a printing sendee.

[0038] Method 400 includes creating and storing a record that associates the service with the client device, at 420. For example, the access point may analyze the query to determine the type of service requested by the client device, information relating to the client device and the type of service requested is stored as a record (e.g., in a table).

[0039] Method 400 includes forwarding the query to a network device hosting the requested service via unicast transmission, at 430. For example, the access point may forward a unicast service request to a network device such as a printing device that may service the request.

[0040] Method 400 includes setting a threshold time for receiving a service announcement from the network device, at 440. For example, the access point may set a timer (e.g., a few second) to receive a service announcement from the network device.

[0041] Method 400 includes receiving the service announcement from the network device, where the service announcement includes a type of service requested by the client device, at 450. For example, the access point may receive a service announcement from the network device.

[0042] Method 400 includes determining whether the service announcement is received wi hin the threshold time, at 460. if the service announcement is received within the threshold time, the service announcement is forwarded to the client device via unicast transmission, at 470. If however, it is determined at 460 that the service announcement is received after the threshold time has elapsed, the service announcement is discarded, at 480,

[0043] FIG. 5 is a block diagram of a multicast transmission manager including a computer- readable medium having instructions for managing multicast transmissions, according to one example. Multicast transmission manager can be a wireless network access point, a base station, ad-hoc device, a controller, or any other network manager. Manager 502 can include non-transitory computer-readable medium 520. Medium 520 can include instructions 521- 526 that, if executed by a processor 12, can cause the processor to perform the functionality of the manager 501.

[0044] For example, multicast service request receiving instructions 521 are executable to receive a multicast transmission from a client device, where the multicast transmission includes a service request. Service request analyzing instructions 522 are executable to analyze the service request to determine a type of service requested by the client device. Record creating and storing instructions 523 are executable to create and store a record that associates the type of service to the client device. Service request forwarding instructions 524 are executable to forward the service request via unicast transmission to a network device known to host the type of service. Service response receiving instructions 525 are executable to receive a response to the service request from the network device. Service response forwarding instructions 526 are executable to forward the response to the client device via unicast transmission.

[0045] The examples described above may be embodied in a computer-readable medium for configuring a computing system to execute the method. The computer-readable media may include, for example and without limitation, any number of the following non-transitive mediums: magnetic storage media including disk and tape storage media; optical storage media such as compact disk media (e.g., CD-ROM, CD-R, etc.) and digital video disk storage media; holographic memory; nonvolatile memory storage media including semiconductor- based memory units such as FLASH memory, EEPROM, EPROM, ROM; ferromagnetic digital memories; volatile storage media including registers, buffers or caches, main memory, RAM, etc.; and the internet, just to name a few. Other new and obvious types of computer- readable media may be used to store the software modules discussed herein. Computing systems may be found in many forms including but not limited to mainframes,

minicomputers, servers, workstations, personal computers, notepads, personal digital assistants, various wireless devices and embedded systems, just to name a few.

[0046] In the foregoing description, numerous details are set forth to provide an

understanding of the present invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these details. While the invention has been disclosed with respect to a limited number of examples, those skilled in the art will appreciate numerous modifications and variations therefrom. It is intended that the appended claims cover such modifications and variations as fall within the true spirit and scope of the invention.

Claims

CLAIMS WHAT IS CLAIMED IS:

1. A method for managing multicast transmissions, comprising:

receiving, at a network access point, a multicast query from a client device, wherein the multicast query includes a service request;

creating and storing a record associating the service with the client device;

receiving a service announcement from a network device hosting the service

requested by the client device; and

forwarding the service announcement to the client device via unicast transmission.

2. The method of claim 1 , further comprising forwarding the query to at least one network device hosting the service requested via unicast transmission, in response to receiving the multicast query.

3. The method of claim 1 , comprising forwarding the service announcement via unicast transmission to a second client device that has previously requested the service based on a second record associating the service with the second client deyice.

4. The method of claim 3, comprising refraining from forwarding the service announcement to a third client device based on an absence of a third record associating the service with the third client device.

5. The method of claim 1 , comprising:

setting a threshold time for receiving the service announcement from the network device in response to the query;

forwarding the service announcement to the client device via unicast transmission if the service announcement is received within the threshold time; and discarding the service announcement if the service announcement is received after the threshold time, wherein the service announcement is not forwarded to the client device.

6. The method of claim 1, comprising analyzing the multicast query to determine a type of service requested and associating the type of service with the client device.

7. A network access point for managing multicast transmissions, comprising:

a processor to:

receive a multicast transmission from a client device, wherein the multicast transmission includes a service request;

determine a type of service requested by the client device;

create and store a record associating the type of service to the client device; forward the service request to a network device via unicast transmission; receive a service announcement from the network device, wherein the service announcement includes the type of service requested by the client device: and

forward the service announcement to the client device via unicast transmission.

8. The network access point of claim 7, the processor to forward the service announcement to a second client de vice that has previously requested the type of service, based on a second record associating the type of service to the second client device.

9. The network access point of claim 7, wherein the service request is forwarded to at least one network device known by the network access point to host the type of service requested.

10. The network access point of claim 7, the processor to set a threshold time for receiving the service announcement from the network device.

1 1 . The network access point of claim 10, wherein the service announcement is discarded if the service announcement is received after expiration of the threshold time.

12. The network access point of claim 10, wherein the service announcement is forwarded to the client device if the service announcement is received within the threshold time. 13, A non-transitory computer-readable storage medium comprising instructions that, when executed by a processor of a muiticast transmission manager, cause the processor to: receive a multicast transmission from a client device, wherein the multicast

transmission includes a service request;

analyze the service request to determine a type of service requested by the client device;

create and store a record that associates the type of service to the client device;

forward the service request via unicast transmission to a network device kno wn to host the type of service;

receive a response to the service request from the network device; and

forward the response to the client device via unicast transmission.

14, The non-transitory computer-readable storage medium of claim 13, wherein the instructions are executable to forward the response via unicast transmission to at least one second client device that has previously requested the type of service, based on at least one second record that associates the type of service to the at least one second client device.

15, The non-transitory computer-readable storage medium of claim 13, wherein the instructions are executable to set a threshold time for receiving the response to the service request, wherein the response is discarded if received after expiration of the threshold time, and wherein the response is forwarded to the client device if received within the threshold time.