RU2534950C2 - Procedure for realising membership in multiple multicast groups of various providers - Google Patents

Abstract

FIELD: physics, computer engineering.

SUBSTANCE: invention relates to systems for realising a membership function in multiple multicast groups of various service providers. The method comprises sending a connection request to a multicast group using an Internet Group Management Protocol (IGMP) Join message; wherein the request is intercepted by MD DSL, respectively processed, recorded in a table and transmitted to a network; adding multicast (McA) VLS to the intercepted information, wherein a central processing unit tags, based on the IP information packet received in the IGMP header, IGMP requests from the user VLS to the network Mc VLS, after which the central processing unit adds to a CAM forwarding table a record on the destination address of multicast content of the service provider with the corresponding Mc VLS-id, wherein the central processing unit sets up the forwarding mechanism with rules for tagging multicast VLS packets on separate ports based on forwarding rules written in the a code mechanism and the forwarding mechanism respectively forwards through the connections the processed IGMP user traffic with the network VLS-id.

EFFECT: providing multicast content in free access networks by multiple service providers, in which multicast mode is used to transmit video content.

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Description

The subject of the invention is a procedure for implementing the Membership function in Many Multicast Groups of various Service Providers (MMPM (Multi-Provider Multi-Provider Multicast Membership)), which is primarily intended for multimedia service providers in Open Access Networks (ONA, Open Networks Access) ), that is, with several service providers in which for the simultaneous provision of video content to several users the Internet Protocol for Group Management (IGMP (Internet Group Management Protocol) is used). The present invention relates to class G01R 31/08 according to international patent classification.

This solution provides the end users with any video content. It extends the IGMP message tracking function in such a way that it allows you to compose any combination of video streams in the direction of the user, despite the fact that a specific user refers only to a specific service provider.

There are no known solutions for tracking IPOG messages with the ability to combine video content of various service providers. The concepts of open access networks, in which the national telecommunications operator, according to the law, must provide its telecommunications infrastructure to alternative operators, as a result of which end-users are given the opportunity to choose services regardless of the infrastructure operator, are only emerging.

When describing a known state, a very important requirement when organizing networks with several service providers is to prevent direct communication between users at the second level of the OSI model (level 2; L2), without taking into account the possibility of filtering traffic at the third or higher level. Network operators have several options for restricting traffic: filters, access lists, user isolation lists. Communication between two users typically goes through a device that provides filtering at a third or higher level OSI model.

Despite this, users on devices that work only at the second level of the OSI model can communicate with each other, since they "see" each other through a second-level connection. The switches and access equipment described in the present invention support the ability to isolate subscriber ports at the second level. When this option is activated, multicast, unicast and broadcast communication between the two ports at level 2 is prevented.

Features of the IP multicast mode with IPIG protocol are defined in IETF RFC 1112.

IGMP is used as a mechanism for the dynamic inclusion of individual users in multicast groups in the corresponding logical subnet of the VLAN (Virtual Local Area Network). IPIG version 2 protocol uses the following message types: query - Query, joining - Join and leaving the group - Leave.

If the user wants to receive some video content, a Join message is sent in the direction of the network, through which a request for media content is transmitted.

If the user no longer wants to receive certain media content, then a Leave message is sent in the direction of the network.

The default state of Layer 2 devices after receiving multicast traffic is broadcast to all ports on the same logical subnet. To effectively send multicast traffic to Layer 2 devices, the IPIG message tracking function is used.

The classic IPIG message tracking function requires some information at the third level of the OSI model for its operation. The IPUG message tracking function appropriately processes this information and adapts the forwarding table (CAM table).

Closest to the present invention is the solution described in patent document US 20070116014 entitled "Enhanced Multikast VLAN Registration (eMVR). However, it is not intended for networks with multiple service providers, but, before In total, for the separation of multicast subscriber traffic and network traffic, a common characteristic of this solution (eMVR) and the functionality of Registration in VLANs of Multicast Transmission (PBM (MVR, Multikast Vlan Registration) is the formation of a separate second VLAN, which is used to distribute multicast traffic. unsolved problem remains quite difficult to ensure combinations of media streams of different logical subnets.

The present invention solves this problem by a procedure which, through the HMGMP function, provides an extension of the existing IPIG message tracking function to support the selection of VLANs.

The invention will be explained using an example implementation with corresponding schemes:

Figure 1 is a block diagram of an Ethernet network in a ring topology;

Figure 2 is a block diagram of an Ethernet network in a ring topology using the invention;

Figure 3 is a block diagram of the operation of a layer 2 switch.

Figure 1 shows a block diagram of an Ethernet network in a ring topology; The dotted line shows the possible connection of the device using the present invention.

Figure 2 shows the connection of users to the network through digital subscriber line (DSL) technology. The device 6 level 3 and a group of switches 5 level 2 through physical connections 7 create a network in the topology of the ring. Access Multiplexer (MD) 3 and switches 4 on DSL digital subscriber lines through connection 7 are connected to the port of Layer 5 switch 5. User 1, related to provider A, is connected to the network via a DSL modem (shown in Figure 2) through the port on MD DSL 3. Also, the second user 2 is connected to the network, only he belongs to the service provider B.

Figure 3 shows the main blocks of the access device MD DSL 3. It consists of a central processor (CPU) 10, a code procedure 9, a transfer table TP (CAM) 11 and a forwarding mechanism 12.

The procedure using the present invention is illustrated by means of the attached figures. Next, technical details will be described by means of a reference arrangement of elements. It must be understood that this function can be used in all possible variants of an open access network (a network with several service providers), as well as to ensure network security.

Figure 2 shows the connection of users to the network through digital subscriber line (DSL) technology. It should be noted here that the invention is not limited to the type of access, and DSL is only one option. An example indicates that users are connected to DSL modems through workstations.

Such a network architecture assumes that all subscriber ports on the DSL 3 MD belong to different VLANs, the so-called access ports. Since a user in one VLAN network cannot communicate with a user located in another VLAN without using a level 3 device 6, this ensures the necessary isolation of users. All ports on Layer 5 access switches are members of all VLANs (TRUNK type), since DSL MDs with several VLANs are connected to them.

Service providers provide multimedia (video) content that will be delivered to end users through DSL modems. Thus, service provider A provides video content for user 1 and service provider B for user 2. Some of the video content is transmitted in multicast mode. The present invention assumes that multimedia multicast content of various service providers is shared by different multicast IP addresses.

According to the described procedure for implementing the membership function in different multicast groups of different service providers, it is clear that the multicast groups are uniquely identified (service providers agree on the division of the address space for multicast transmission).

2, the network architecture assumes that user 1 associated with operator A is a member of the multicast VLAN X and is connected to the dsH port on the DSL MD, which, in turn, is connected via an uplink to a layer 2 switch. User 1 receives the desired video content (Service Provider A) through an address from the address space for multicast. The example assumes that multicast traffic (Service Provider A) at the entrance or exit from the network is indicated by the VLAN McA tag.

An example of functioning at the network level.

When user 1 selects multicast video content in the upstream direction (from the user in the network direction), a request is sent to join this multicast group using the Join IPOG message. This request is intercepted by the DSL 3 MD, processed accordingly, written to the tables, and transmitted further in the direction of the network. Based on predetermined rules, the DSL 3 MD adds to the intercept information of the VLAN MCA. The same is true for all IPOG messages received from this user.

An example of the algorithm:

The Central processor 10, based on the rules prescribed by the code mechanism 9, tags incoming from the subscriber VLAN messages IPOG in the network VLAN MS. Tagging is performed based on the information received in the IPAG header of the IP packet. The parameter to which the tagging is bound is the destination IP address. The central processor 10 adds to the table CAM 11 a record of the destination address of the multicast content of the service provider with the corresponding VLAN-id MS.

The central processor 10 configures the forwarding mechanism 12 with the tagging rules for the VLANs of multicast packets on individual ports based on the forwarding rules recorded in the code mechanism 9. Forwarding mechanism 12 via connections 7 forwards the IPUB subscriber traffic appropriately processed (with the network VLAN ID).

If the user no longer wants to receive the video content of the service provider, then the IPS Leave message is transmitted in the direction of the network, which is intercepted by the central processor 9. If there are no other users who want to receive this video content, then the IPS Leave message with the network VLAN tag is sent to the device level 6 . However, a multicast group entry is deleted on the DSL MD.

Claims (1)

A way to implement the membership function in many multicast groups of various service providers, where the network architecture assumes that all subscriber ports on the Digital Subscriber Line Access Modem (DSL) - DSL MD (3) are members of various Virtual Local Area Networks (VLANs), the user from one VLAN cannot communicate with a user from another VLAN without using a device (6) of level 3, as a result of which the necessary isolation of users is ensured; all ports on Layer 2 access switches (5) are members of all VLANs, since DSL MDs with several VLANs are connected to them, characterized in that the user (1) selects the video content transmitted in multicast mode, for which in the upstream direction, from the user in the direction of the network, a request is sent to join the multicast group using the Internet Group Management Protocol (IGMP (Internet Group Management Protocol)) Join, and the request is intercepted by the DSL MD (3), respectively it is abutted, recorded in the tables and transmitted in the direction of the network and, based on predefined rules, MCA VLAN (VLAN of multicast transmission) is added to the intercepted information, which is performed for all IPAG messages received from this user, and the central processor (10) based on the rules, prescribed by the code mechanism (9), tags on the basis of the information received in the IPOG header of the IP packet information IPIG requests from the subscriber VLAN to the network VLAN Мс (multicast VLAN), and the parameter to which is tagged this is the destination IP address, after which the central processor (10) adds to the CAM forwarding table (11) a record of the destination address of the multicast content of the service provider with the corresponding VLAN-id MS, and the central processor (10) sets up the forwarding mechanism (12 ) with the rules for tagging VLANs of multicast packets on individual ports based on the forwarding rules recorded in the code mechanism (9), and the forwarding mechanism (12) through connections (7) sends the correspondingly processed network VLAN-id entsky traffic IGUP.

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