Table of Contents

Configuring BME Multicasting

Configuring BME Multicasting

This chapter presents an overview of multicasting, a description of the BME card used on the BPX switch for multicasting for PVCs, and configuration instructions:

• Introduction
  
  
• BME Operation
  
  
• Hot Standby Backup
  
  

The BME provides multicast services in the BPX switch. It is used in conjunction with a two-port OC-12 backcard.

Multicasting point-to-multipoint services meets the demands of those requiring virtual circuit replication of data (Frame Relay and ATM) performed within the network. Some examples of functions benefiting from multicasting are:

• Retail—point-of-sale updates
  
  
• Router topology updates
  
  
• Desktop multimedia
  
  
• Video conferencing
  
  
• Video distribution, for example, IP multicast video networks to the desktop
  
  
• Remote learning
  
  
• Medical imaging
  
  

BME Standards are:

• UNI 3.1 Multicast Server
  
  
• UNI 4.0 Leaf Initiated Joins and related standards
  
  

Multicasting point-to-multipoint connections benefits include:

• Decreased delay in receiving data
  
  
• Near simultaneous reception of data by all leaves
  
  

BME Features

• The BME is a two-port OC-12 card
  
  
• Supports up to 1000 multicast groups
  
  
• Supports up to 8064 connections, at 4032 per port. It can support the following combinations:
  
  
  • 1000 roots with 8 leaves in each multicast group
    
    
  • 100 roots with 80 leaves in each multicast group
    
    
  • 2 roots with 4000 leaves in each multicast group
    
    
  • or any other such combination.
    
    
• Supports CBR, UBR, VBR, and ATFR connections
  
  
• Hot standby
  
  

BME Requirements

• Firmware of type BMEMK, where K is the model number for BME.
  
  
• upln is used to bring up line 1 and line 2.
  
  
• upport is used to bring up port 1 and port 2, respectively.
  
  

BME Restrictions

• BMEs can function in the following two BPX node configurations:
  
  
  • BCC-4s
    
    
  • BXMs
    
    
• VC frame merge is not currently supported
  
  

Address Criteria

• The VPI of a multicast connection indicates the multicast group to which it belong.
  
  
• The VPI.VCI assigned to a multicast connection is unique for that card.
  
  
• If the VCI = 0 for a multicast connection, this indicates a root connection.
  
  
• If the VCI is not = 0 for a multicast connection, this indicates a leaf connection.
  
  
• If the root connection of a given multicast group is added to port 1 of the two port card, then the leaves belonging to that multicast group must be added to port 2, and vice versa.
  
  

For example, if 12.1.50.0 is added on port 1, then the leaves should be:

12.2.50.50
12.2.50.100
12.2.50.101 and so on.

Similarly, if a root 12.2.60.0 is added on port 2, then the leaves should be

12.1.60.101
12.1.60.175, and so on.

Connection Management Criteria

Root connections and leaf connections can be added in any order:

• Add root first and then leaves.
  
  
• Add leaves first and then root.
  
  
• Add root in between adding leaves.
  
  

Root and leaf connections can be deleted in any order.

Root can be deleted and replaced with a new root.

Connection Management with Cisco WAN Manager

Cisco WAN Manager management includes these functions:

• Connection filtering by multicast type (root/leaf)
  
  
• Multicast connection addition, deletion, and modification
  
  
• Multicast view of multicast group of a selected connection
  
  
• No multicast specific statistics support
  
  
• No service MIB support
  
  

BME Operation

Cables are connected between port 1 and port 2 of the backcard, transmit to receive and receive to transmit.

Note   Removing the physical loopback cables or placing line 1 or 2 into loopback will prevent the cells from the root reaching the leaves.

BME Cell Replication

Figure 27-1 shows a BME with a single root input multicasting with 3 leaves. The root connection can be added at a BPX switch (BPX switch A) distant from where the traffic is replicated by the BME card (BPX switch F) and routed through a number of BPX nodes. Similarly, the leaves can be routed from the multicasting node through a number of nodes before reaching their destination.

Cell Replication Stats

As an example of how traffic appears on the BME, if there is one root at port 1 with two leaves at port 2, and traffic is passed on the root at 500 cells/sec, then one should see an egress port stat of 1000 cell/sec on port 1 and an ingress port stat of 1000 cells/sec on port 2, as shown in Figure 27-2.

Adding Connections

Two multicasting groups are shown in Figure 27-3. For purposes of the illustration only a few leaves are shown for each connection. However, as described previously, each multicasting group could contain up to 8064 connections.

In this example, the two connections with a VCI of 0 each define a multicasting root connection. Their VPI defines a broadcasting group.

One group is defined by 2.1.70.0, where the VCI of zero defines the root connection to a BME, and the VPI of 70 defines a group. All the leaves in that group are of the form 2.2.70.x.

The other group is defined by 2.2.80.0, where the VCI of zero defines the root connection to a BME, and the VPI of 80 defines a group. All the leaves in that group are of the form 2.1.80.x.

Multisegment Multicast Connections

Figure 27-4 shows an example of a multisegment multicast connection where a leaf connection from one BME can become a root connection for another BME. This capability allows the users to configure multisegment, multicast tree topologies.

Multicast Statistics

Channel statistics are available for leaf connections on the BME end. However, channel statistics are not available for the root connection on the BME end.

For the example in Figure 27-5, execute the following commands to display channel statistics for the leaf connections:

• dspchstats 12.1.50.75 on BPX switch 1 (available)
  
  
• dspchstats 5.2.75.40 on BPX switch 2 (available)
  
  
• dspchstats 11.9.123.432 on BPX switch 3 (available)
  
  

For the example in Figure 27-5, the following command will not display channel statistics (because 5.1.75.0 is a root connection):

• dspchstats 5.1.75.0 on BPX switch 2 (not available)
  
  

Policing

Policing is supported on all leaf connections on the BME end.

All policing types available on the BXM are available on the BME leaves.

No policing functionality is available on the root connection on the BME end.

Hot Standby Backup

BME cards can be set up to provide hot standby backup. Both cards are set up with port 1 connected to port 2 on the same card to provide the multicasting connection, transmit to receive and receive to transmit. There is no Y-cabling connection between the cards, and they do not have to be adjacent to each other.

The addyred command is used to enable hot standby backup between the cards. The addyred command must be used before any connections are added to the active card. The command will be rejected if used after connections have been added to the active card.

Configuration

If the multicast tree has a large number of leaf connections, for example, 3000, then the cnfportq command should be used to configure the Qbin threshold to be greater than needed for half the number of leaves so as to assure that the multicast group will have no discards. The Qbin default depth is about 1200 cells.

The following is a Qbin example using the cnfportq command:

 
j4b            VT    SuperUser     ~ BPX 15    9.3 March 24 2000 16:59 PST 
Port:       3.2     [ACTIVE  ]
Interface:          LM-BXM
Type:               NNI
Speed:              1412830 (cps)
SVC Queue Pool Size:          0
CBR Queue Depth:              1200
CBR Queue CLP High Threshold: 80%
CBR Queue CLP Low Threshold:  60%
CBR Queue EFCI Threshold:     80%
VBR Queue Depth:              10000   UBR/ABR Queue Depth:               40000
VBR Queue CLP High Threshold: 80%     UBR/ABR Queue CLP High Threshold:  80%
VBR Queue CLP Low Threshold:  60%     UBR/ABR Queue CLP Low Threshold:   60%
VBR Queue EFCI Threshold:     80%     UBR/ABR Queue EFCI Threshold:      30%
                                                                                
This Command: cnfportq 3.2  
SVC Queue Pool Size [0]: 
Virtual Terminal      CD