SI23484A - Procedure for realization of the functional multiprovider multicast membership in 802.1 ad networks - Google Patents

Abstract

Procedure for realization of the functional multiprovider multicast membership according to the invention solves the problem of providing multicast contents to the users in multiprovider metro environments, which are based on the standard 802.1ad and for the transfer of the video contents a multicast transmission mode is used. The invention substantially enhances the functionality of the IGMP snooping to the extent that the user, who belongs to one provider can be provided with all the combinations of video content by many service providers despite belonging to a single one.

Description

PROCEDURE FOR THE PERFORMANCE OF A FUNCTIONAL MULTIPURPOSE

MEMBERSHIP MULTIQUE IN 802.1 AD NETWORKS

The subject of the invention is a process for implementing a functional multi-provider multicast membership in 802.1ad networks (Multi Provider Multicast Memebership and 802.1ad networks, shorter MPMM-PeB), which is preferably intended for multimedia service providers in multi-provider metropolitan networks (OPN, open access netvvorks), which use the established Internet Group Management Protocol (IGMP) to provide video content to multiple users at one time, and meet the criteria of the 802.1ad standard, which is rules-based and dual VLAN tagging.

The technical problem solved by the invention allows the provision of any video content to the end user in accordance with 802.1ad. The solution extends the IGMP snooping functionality to such an extent that it is possible to assemble combinations of video data streams to the user, despite the fact that the user belongs to only one service provider.

There are no known IGMP snooping solutions with the ability to combine video content from multiple providers under 802.1 ad services. Multi-provider network concepts where the national telecommunications operator (as required by law) must also offer its telecommunications infrastructure to alternative service providers and enable end-users to

select services independently from the infrastructure operator, they are just getting established. The invention extends the invention to a process for the implementation of a multi-operator multicast membership code P-200800315.

An important requirement for multi-provider metropolitan networks is to disable direct communication between two users on the second layer of the OSI model (Layer2, shorter L2), without the possibility of filtering traffic on the third or higher layer. Network operators have more options for blocking traffic (filters, access sheets, isolation sheets). As a rule, communication between two users is allowed by the operator only through a device that enables filtration at the third or higher level of the OSI stack.

However, users on a device that operates only at the second level of the OSI Fund can communicate with each other solely due to the fact that they are visible through the L2 connection. The switches and accessory equipment of the present invention support the option of isolating user L2 ports. When activated, multicast, unique and broadcast communication between two L2 ports is disabled.

The specifics of IP multicast transmission mode using the IGMP protocol are defined in IETF RFC 1112. The specifics of the rules and restrictions applicable in »provider edge bridges; PEB 'networks describe the IEEE 802.1ad standard.

One of the regularities of PEB networks is the prohibition of mixing user (C-VLAN traffic) from service (S-VI_AN traffic). The invention is not limited to the request of PEB, but allows the combination of the use of different VLANs (S, C or SinC) for the purposes of realistic network layout.

The IGMP protocol is used as a mechanism for dynamically integrating individual users into multicast groups in the associated logical subnet (VLAN). IGMP version 2 uses Query, Join, and Leave messages.

If the user wants to get involved in receiving multicast content, he sends a Join message to the network, expressing his desire to receive media content.

If the user no longer wants to receive certain multimedia multicast content, he / she logs off with a Leave message.

The default state of L2 devices after receiving multicast traffic is broadcasting to all ports that are subscribed to the same logical network. IGMP sniffing is used to efficiently distribute multicast traffic flow on L2 devices.

The classic IGMP sniffing function requires some information contained in the third layer of the OSI stack to function. The IGMP sniffers process them appropriately and adjust the MAC table.

According to the invention, the problem is solved by a process for performing a functional multi-provider multicast membership that extends existing IGMP snooping with the option of selecting a logical subnet (VLAN) according to the standard

802.1ad.

The description of the invention will be explained by means of the pictures which are part of the document. The following will describe a lot of technical details using the reference layout of the elements. However, be aware that the feature can be used in all possible versions of a multi-provider metro network that meets the requirements of the 802.1ad standard or solely to provide security on 802.1ad metro networks.

The pictures provided show:

Figure 1 is a block diagram of an Ethernet network in an annular io layout;

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

Figure 3 is a block diagram of the operation of an L2 switch;

Figure 4 valid and invalid Ethernet slices in the user and service VLAN space;

figure 5 user and service VLAN space.

Figure 1 shows a block diagram of a network in a ring layout. The figure indicates with the dashed element the possible connection of the device of the invention.

The invention will be presented by separating user (C-VLAN) traffic in advance known via Ethernet type (hex) 0x8100 from service (S-VLAN) traffic (hex) 0x88a8 type (Figure 4). Ethernet values are standard and are specified by the 802.1ad standard. Figure 5 shows the user rules

VLAN space and VI_AN service space rules provided by the 802.1 ad standard.

The invention is not limited to standard Ethernet values, but allows the choice of any Ethernet value.

Figure 2 shows the connection of users to the network through DSL (digital subscriber line) technology. The L3 device 6 and the cluster of network L2 switches 5 form a network in a ring topology via physical links 7. DSLAM (DSL Access Multiplexer) 3 is connected to connection port L2 of switch 5 via connection 7. User 1 belonging to service provider-A, io is via DSL modem (not shown in Figure 2) and connection port to Connected to the DSLAM 3. Equally, user 2 is connected to the network, except that it belongs to provider B.

The network layout (Figure 2) shows the connection of users to the network via DSL (digital subscriber line) technology. The point here is that the invention is not limited to the type of access, DSL is only one possible way. In addition to DSL, the user can connect via optical, copper, aerial or any other accessible technology.

The L3 device 6 and the cluster of network L2 switches 5 form a network in a ring topology via physical links 7. DSLAM (DSL Access

Multiplexer) 3 is connected to connection port L2 of switch 7 via connection 7. All together, it forms a network topology that complies with 802.1ad 8.

User 1, which in the 802.1ad network represents itself as a C1 VLAN and belongs to the service provider 1 (hence the S1 VLAN) is connected to the network via a DSL modem (not shown in Figure 2) and a connection port on DSLAM 3. Equally, user 2 is connected to the network, except that it belongs to provider 2 (S2 VLAN). So it is known in the network as C2, S2 (C2 as user 2).

Figure 3 shows the basic blocks of the DSLAM access device. It consists of a central processing unit 10, a process code 9, a CAM forwarding table 11, and a forwarding engine 12.

Figure 4 shows the types of Ethernet frames according to the 802.1ad standard. From io standpoints of 802.1ad compliance, (hex) eth_type 0x8100 is used for C VI_AN and for S VLAN (hex) eth_type 0x88a8.

The example points to the fact that users are connected to DSL modems via workstations.

The network layout assumes that all user ports on the DSLAM are 3 members of different C VLANs. At the same time, an S-VLAN representing the network operator is added to the user C-VLANs, using the (hex) value in eth_type 0x88a8. The user port on which both the C-VLAN and the S-VLAN are added is called a VLAN stacking port. Because the user cannot communicate with the user on one set of VLANs,

2o belonging to the second VLAN assembly without the use of L3 device 6, the desired insulation is thus achieved. Each connection port on the access switches (5) is a member of all VLANs (TRUNK type) as DSLAMs with multiple VLANs connect to it.

The service providers provide multimedia (video) content that will be transmitted to the users via DSL modems. Thus, provider 1 provides video content to user 1 and provider 2 to user 2. Part of the video content is transmitted in multicast distribution mode. The invention provides that multicast multimedia content of both providers is separated by used multicast IP (Internet protocol) addresses.

The process of the invention assumes that one-line labeling of multicast groups is provided (service providers agree on a multicast address space).

io The network layout (Figure 2) assumes that user 1, (which belongs to operator A) is a member of multicast VLAN S1, connected to port dsl1 on DSLAM, which is connected to L2 switch 5 via uplink 7. User 1 obtains the desired video content (service provider A) via the title in the multicast title space. The example assumes that multicast is traffic (service provider 1) in or. from the network tag with VLAN S1.

The invention provides that user traffic in or tag / remove to network only S-VLAN (described by VLAN-id, and its corresponding eth_tip; standard (hex) 0x88a8), a combination of C and S VLANs, respectively. C VLAN only (this option does not adhere to the 802.1ad standard. If multicast content is transmitted in the service area (denoted by S VLAN), this is referred to as MC service VLAN.

Example of network-level operation:

When user 1 selects multicast video, a request to enroll in multicast video content is sent upstream (from user to network) via the IGMP Join message. DSLAM 3 intercepts this request, writes it to tables and processes it, and sends it to the network. Based on predefined rules, DSLAM adds C1 and the corresponding S VLAN to the intercepted information. It does the same for all IGMP messages sent from this user.

An example of how the algorithm works:

The processor unit 10, based on the rules prescribed by the code io mechanism 9, indicates the incoming IGMP requests from the user VLAN to only the network VLAN S, the combination of the user C VLAN in conjunction with the network VLAN, or. only in the user VLAN. Labeling is based on the information received from the IP packet. The information to which the tagging is attached is the destination IP address. CPU (10) adds to the CAM table (11) a destination address record for multicast provider content with associated VLAN-id (or a combination of them).

CPU 9 sets up a dispatch mechanism 12 with VLAN tagging rules for multicast packets on individual ports based on the dispatch rules written in code procedure 9. The dispatch mechanism 12 sends via links 7 appropriately customized (with network VLAN id)

IGMP traffic.

When the user no longer wants to receive video content from the provider, he sends an IGMP Leave message intercepted by CPU 9.

Claims (1)

1. A process for implementing a functional multi-provider multicast membership of 802.1ad networks, wherein the network layout assumes that users connect to the L2 network via different DSLAMs (3) and service providers via switches (5), the process assuming that such a network built over 802.1ad rules that allows for a multi-vendor environment. characterized in that the user (1) selects a multicast video that sends the request upstream and downstream to join the multicast video content via an IGMP join message to properly capture the DSLAM request (3) into tables and process, and send to the network and based on predefined rules (predefined IP address set) adds MC to the intercepted information VLAN; 20 that the user (1) selects multicast video, sends it upstream, the DSL modem adds the user C-VLAN, and DSLAM (3) adds MC service to the intercepted information based on the predefined rules (predefined IP address set) VLAN; that user (1) selects a multicast video that sends the request upstream 25 directions for joining multicast video content via an IGMP join message to properly capture the DSLAM request (3) in tables and process, and send to the network and add to the intercepted information based on predefined rules (predefined IP address set) user VLAN and MC service VLAN; that the DSLAM (3) also knows the sniff function for service / non-VLANs.