Example: Configuring Transactional Multicast for IGMP

The example in this section explains how to configure ANCP mapping.

Requirements

This example uses the following software and hardware components:

Overview

By using ANCP, IGMP is no longer terminated or proxied at the access node. Instead, IGMP passes through the access node transparently. B-RAS terminates both the data PVC and IGMP. After any user permission verification, B-RAS may instruct the access node (using GSMP) to establish a multicast branch for the subscriber port.

ANCP works with a special IGMP session to collect OIF mapping events in a scalable manner. This session enables ANCP to listen to OIF mappings and, in turn, convey cross connect events to the appropriate ANCP neighbor (access node). For additional information about configuring IGMP and about OIF mapping, see Configuring IGMP in JunosE Multicast Routing Configuration Guide.

ANCP IGMP Configuration Topology

In the following example (Figure 18), two subscribers access individual multicast channels through cross connections (branches) that occur on the access node.

Figure 18: Using ANCP with an Access Node

Using ANCP with an Access Node

ANCP IGMP Configuration

To configure ANCP mapping, perform these tasks:

Note: You can customize and use the following example in your own network. You can copy the text into a text editor and modify it (removing all prompts and changing values) for immediate use or save the modified example as a script (.scr) file. Script files allow you to execute commands as though they were entered at the terminal. For information about creating and executing script files, see Command Line Interface in JunosE System Basics Configuration Guide.

  1. Configure an OIF map for the access node that maps each multicast group to an outgoing interface.
    host1(config)#ip igmp oif-map OIFMAP atm 2/0.101 232.1.1.1 10.1.1.1 host1(config)#ip igmp oif-map OIFMAP atm 2/0.102 232.1.1.2 10.1.1.2
  2. Define ANCP parameters.
    host1(config)#l2c host1(config-l2c)#session-timeout 15
  3. Enable ANCP to listen to OIF mapping events from IGMP in this virtual router.
    host1(config)#l2c ip oif
  4. Create a listening TCP socket in the virtual router (TCP port 6068).
    host1(config)#l2c ip listen
  5. Define ANCP neighbor parameters.
    host1(config-l2c)#neighbor ACCESS_NODE_1 host1(config-l2c-neighbor)#id 09af.15bc.3156

    Note: The ID is a 48 bit quantity that identifies the ANCP neighbor.

  6. Configure the ANCP multicast labels (input labels) on the corresponding outgoing interfaces.
    host1(config)#interface atm 2/0.101 host1(config-interface)#ip igmp version passive host1(config-interface)#l2c peer-attachment-id “ in_multicast_port_3” host1(config)#interface atm 2/0.102 host1(config-interface)#ip igmp version passive host1(config-interface)#l2c peer-attachment-id “ in_multicast_port_5”
  7. Configure the ANCP output labels, the neighbor information on the subscriber interfaces, and apply the OIF map.
    host1(config)#interface atm 2/0.11 host1(config-interface)#ip igmp apply-oif-map OIFMAP host1(config-interface)#l2c end-user-id “ out_subscriber_port_6” neighbor ACCESS_NODE_1 host1(config)#interface atm 2/0.12 host1(config-interface)#ip igmp apply-oif-map OIFMAP host1(config-interface)#l2c end-user-id “ out_subscriber_port_7” neighbor ACCESS_NODE_1

    When Subscriber A requests to join 232.1.1.1, ANCP transmits an add branch message with the corresponding input and output labels that cross-connect
    port 3 and port 6 on Access Node 1.

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