Configuring Multicast in the GPON Network

Information About Configuring Multicast in the GPON Network

About Multicast

The GPON system works on a master-slave ONU Management Control Interface (OMCI) protocol. In the GPON system, the OLT is the master, the ONT is the slave and the OMCI protocol allows the OLT to configure, manage and control the attached ONT device. The OMCI protocol establishes a proprietary OMCI channel transmission control messages between the OLT and the ONT. The configuration of the ONT-related multicast function is configured and delivered through the OLT. There are two types of ONT multicast modes:

  • IGMP-snooping mode

  • Controllable multicast mode

About IGMP Snooping

IGMP snooping examines IGMP protocol messages to discover which interfaces are connected to hosts or other devices interested in receiving this traffic. Multicast service packets are forwarded only to those hosts listed in the forwarding table. The forwarding table entries are created, maintained, and deleted dynamically based on the host members joining and leaving. IGMP report requests from the ONT are not required to pass the authentication table issued from the OLT, which allows the forwarding table to be updated by directly snooping the IGMP packets. IGMP snooping allows users to watch multicast programs on demand.

About Multicast Group Entry

You can view the multicast group entries learned by the ONT. The HGU type ONT can only be based on global view, and the SFU type ONT is based on port view.

About Multicast Group Learning Limitation

The multicast group learning limitation allows to limit the number of multicast group entries learnt on the ONT. By default, the maximum number of multicast groups learnt on an ONT interface is the maximum number of hardware entries used on an interface. If the number of multicast group entries exceed the configured value, then previous learnt multicast group entries will not be deleted, and new IGMP join messages are dropped. The multicast group limit is configured on the OLT to control the number of multicast group learning on the ONT or ONT port. You must configure the ONT multicast mode before configuring the multicast group limitation.

About Fast Leave

The ONT processes the IGMP leave message in the following ways:

  • Normal leave: The local multicast entry is not deleted immediately after the IGMP leave message is received and waits for the multicast query timeout to expire. If an IGMP join message is not received before the multicast query timeout then the local multicast entry is deleted.

  • Fast Leave: The local multicast entry is deleted immediately after the IGMP leave message is received and the multicast table resource is freed.

About VLAN tagging on Downlink Multicast Packets

Multicast packets in the downlink path are assigned to a dedicated channel forwarding gemport 4095 on the PON system.

The VLAN tagging on downlink multicast packet feature allows you to configure a VLAN policy on the ONT. Based on the VLAN policy, the ONT performs VLAN tagging on the downlink multicast group packet. The multicast group packet can either be a service packet or a query packet. The packet is then only forwarded to the attached STB device.

The HGU-type ONT is based on the global, and the SFU-type ONT is based on the port.

Configuring VLAN tagging on a downlink multicast packet includes removing a tagging rule, adding a tagging and a translating rule. If VLAN tagging on an uplink multicast packet feature is not configured, then the default flow rule is processed.

How to Configure Multicast in the GPON Network

Configuring IGMP Snooping

To configure IGMP snooping, perform this procedure.

Procedure

  Command or Action Purpose
Step 1

enable

Example:

Device> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2

configure terminal

Example:

Device# configure terminal

Enters global configuration mode.

Step 3

deploy profile line

Example:

Device(config)# deploy profile line

Enters command configuration mode
Step 4

aim {index_num [name name] | name name}

Example:

Device(deploy-profile-line)# aim 5

Creates the line profile.

  • index_num : The index of the template. The range is from 0 to M, where M is the maximum number of ONUs supported by the whole machine.

  • name : The name of the template in string. The string length is from 1 to 128.

Step 5

multicast mode igmp-snooping [port port_id]

Example:

Device(deploy-profile-line)# multicast mode igmp-snooping port 2

Enables IGMP snooping.

port_id : The ONT Ethernet port ID. The range is from 1 to 24.

Configuring Multicast Group Learning Limitation

To configure multicast group learning limitation, perform this procedure.

Before you begin

You must configure the ONT multicast mode before configuring this function.

Procedure

  Command or Action Purpose
Step 1

enable

Example:

Device> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2

configure terminal

Example:

Device# configure terminal

Enters global configuration mode.

Step 3

deploy profile line

Example:

Device(config)# deploy profile line

Enters command configuration mode.
Step 4

aim {index_num [name name] | name name}

Example:

Device(deploy-profile-line)# aim 5

Creates the line profile.

  • index_num : The index of the template. The range is from 0 to M, where M is the maximum number of ONUs supported by the whole machine.

  • name : The name of the template in string. The string length is from 1 to 128.

Step 5

[no] multicast group-limit num [port {port_id}]

Example:

Device(deploy-profile-line-5)# multicast group-limit 2

Configures maximum number of multicast groups.

  • num ：The maximum multicast group number. The range is from 1 to 128.

  • port_id : The ONT Ethernet port ID. The range is from 1 to 24.

Use the no multicast group-limit [port port_id] command to delete this feature.

Configuring Fast Leave

To configure fast leave, perform this procedure.

Before you begin

You must configure the ONT multicast mode before configuring this function.

Procedure

  Command or Action Purpose
Step 1

enable

Example:

Device> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2

configure terminal

Example:

Device# configure terminal

Enters global configuration mode.

Step 3

deploy profile line

Example:

Device(config)# deploy profile line

Enters command configuration mode.
Step 4

aim {index_num [name name] | name name}

Example:

Device(deploy-profile-line)# aim 5

Creates the line profile.

  • index_num : The index of the template. The range is from 0 to M, where M is the maximum number of ONUs supported by the whole machine.

  • name : The name of the template in string. The string length is from 1 to 128.

Step 5

[no] multicast fast-leave disable [port port_id]

Example:

Device(deploy-profile-line)# multicast fast-leave disable

Disables fast leave.

port_id : The ONT Ethernet port ID. The range is from 1 to 24.

Use the no multicast fast-leave disable [port port_id ] to enable the fast leave.

Configuring Downlink Multicast Packet Tagging Rule

To configure downlink multicast packet tagging rule, perform this procedure.

Before you begin

You must configure the ONT multicast mode before configuring this function.

Procedure

  Command or Action Purpose
Step 1

enable

Example:

Device> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2

configure terminal

Example:

Device# configure terminal

Enters global configuration mode.

Step 3

deploy profile line

Example:

Device(config)# deploy profile line

Enters command configuration mode.
Step 4

aim {index_num [name name] | name name}

Example:

Device(deploy-profile-line)# aim 5

Creates the line profile.

  • index_num : The index of the template. The range is from 0 to M, where M is the maximum number of ONUs supported by the whole machine.

  • name : The name of the template in string. The string length is from 1 to 128.

Step 5

[no] multicast ds-tag remove [port {port_id}]

Example:

Device(deploy-profile-line-5)# multicast ds-tag remove

Configures the ONT downlink multicast VLAN tag removing rule.

port_id : The ONT Ethernet port ID. The range is from 1 to 24.

Use the no multicast ds-tag [port port_id] to delete the downlink multicast VLAN tag rule.

Step 6

multicast ds-tag add vid [priority | port {port_id}]

Example:

Device(deploy-profile-line-5)# multicast ds-tag add 3

Configures the ONT downlink multicast VLAN tag adding rule.

  • vid : The VLAN ID. The range is from 1 to 4094.

  • priority : The 802.1P priority. The range is from 0 to 7.

  • port_id : The ONT Ethernet port ID. The range is from 1 to 24.

Step 7

multicast ds-tag translate vid [priority | port {port_id}]

Example:

Device(deploy-profile-line-5)# multicast ds-tag translate 3

Configures the ONT uplink multicast VLAN tag translating rule.

  • vid : The VLAN ID. The range is from 1 to 4094.

  • priority : The 802.1P priority. The range is from 0 to 7.

  • port_id : The ONT Ethernet port ID. The range is from 1 to 24.

Monitoring Multicast Entry

The commands in the following table can be used to monitor multicast entry

Table 1. Multicast Entry

Command

Purpose

show ont multicast ont_id [port port_id]

Displays information about multicast learning table on ONT

  • port_id : The ONT Ethernet. The port id is 1 from 24.

  • ont_id ：The ONT ID. The slot_num or port_num or ont_id.

Configuration Examples for Multicast in the GPON Network

Example: Configuring IGMP

The following example shows how to configure the SFU multicast working mode to be IGMP snooping. The user's IGMP report can directly trigger establishing multicast forwarding entries through IGMP snooping. 

Device> enable
Device# configure terminal 
Device(config)# deploy profile line
Device(deploy-profile-line)# aim 100
Device(deploy-profile-line-100)# device type c40-100 
Device(deploy-profile-line-100)# tcont 1 profile dba 1
Device(deploy-profile-line-100)# gemport 1 tcont 1 vlan-profile 1
Device(deploy-profile-line-100)# mapping 1 vlan 10 gemport 1
Device(deploy-profile-line-1)# multicast mode igmp-snooping port 1
Device(deploy-profile-line-100)# active 
Device(deploy-profile-line-100)# end

The following example shows how to configure the HGU multicast working mode as IGMP snooping 

Device> enable
Device# configure terminal
Device(config)# deploy profile line 
Device(deploy-profile-line)# aim 100
Device(deploy-profile-line-100)# device type c30-423
Device(deploy-profile-line-100)# tcont 1 profile dba 1
Device(deploy-profile-line-100)# gemport 1 tcont 1 vlan-profile 1
Device(deploy-profile-line-100)# mapping 1 vlan 10 gemport 1
Device(deploy-profile-line-1)# multicast mode igmp-snooping 
Device(deploy-profile-line-100)# active 
Device(deploy-profile-line-100)# end

The following example shows how to configure the service line profile refer controllable multicast profile. 

Device> enable
Device# configure terminal 
Device(config)# deploy profile line
Device(deploy-profile-line)# aim 100
Device(deploy-profile-line-100)# device type c40-100 
Device(deploy-profile-line-100)# tcont 1 profile dba 1
Device(deploy-profile-line-100)# gemport 1 tcont 1 vlan-profile 1
Device(deploy-profile-line-100)# mapping 1 vlan 10 gemport 1
Saturn(deploy-profile-line-1)# multicast mode olt-control port 1
Device(deploy-profile-line-100)# multicast profile refer 1
Device(deploy-profile-line-100)# active 
Device(deploy-profile-line-100)# end

The following example shows how to configure the service line profile refer controllable profile.

Device> enable
Device# configure terminal
Device(config)# deploy profile line
Device(deploy-profile-line)# aim 100
Device(deploy-profile-line-100)# device type c30-423
Device(deploy-profile-line-100)# tcont 1 profile dba 1
Device(deploy-profile-line-100)# gemport 1 tcont 1 vlan-profile 1
Device(deploy-profile-line-100)# mapping 1 vlan 10 gemport 1
Device(deploy-profile-line-100)# active 
Device(deploy-profile-line-100)# end
#

The following example shows how to configure the translate rule of the SFU for upstream multicast packets. IGMP snooping on the OLT learns the multicast group according to the VLAN after the VLAN tag translation. 

Device> enable
Device# configure terminal 
Device(config)# deploy profile line 
Device(deploy-profile-line)# aim 100
Device(deploy-profile-line-100)# device type c30-423
Device(deploy-profile-line-100)# tcont 1 profile dba 1
Device(deploy-profile-line-100)# gemport 1 tcont 1 vlan-profile 1
Device(deploy-profile-line-100)# mapping 1 vlan 10 gemport 1
Device(deploy-profile-line-1)# multicast mode igmp-snooping
Device(deploy-profile-line-100)# multicast us-tag translate 10 1
Device(deploy-profile-line-100)# active 
Device(deploy-profile-line-100)# end

The following example shows how to configure the port of the SFU to untag and forward the downlink multicast packets. 

Device> enable
Device# configure terminal 
Device(config)# deploy profile line
Device(deploy-profile-line)# aim 100
Device(deploy-profile-line-100)# device type c40-100 
Device(deploy-profile-line-100)# tcont 1 profile dba 1
Device(deploy-profile-line-100)# gemport 1 tcont 1 vlan-profile 1
Device(deploy-profile-line-100)# mapping 1 vlan 10 gemport 1
Device(deploy-profile-line-1)# multicast mode igmp-snooping port 1
Device(deploy-profile-line-1)# multicast ds-tag remove port 1
Device(deploy-profile-line-100)# active 
Device(deploy-profile-line-100)# end