Cisco ACNS Software Deployment and Configuration Guide, Release 5.1 - Chapter 5: Configuring the ACNS Network for Content Distribution [Cisco Application and Content Networking System (ACNS) Software]

Table Of Contents

Configuring the ACNS Network for Content Distribution

Preparing for Channel Distribution of Content

Creating and Modifying Locations

Deleting Locations

Viewing the Location Tree

Creating and Modifying Content Providers

Deleting Content Providers

Viewing Content Providers

Creating and Modifying Websites

Deleting Websites

Viewing Websites

Creating and Modifying Channels

Creating a Channel

Modifying a Channel

Designating the Root Content Engine

Adding and Removing Content Engines from Channels

Adding and Removing Device Groups from Channels

Updating Channel Content

Deleting Channels

Viewing Channels

Channel Routing Algorithm

Preparing for Multicasting

Multicast Distribution Overview

About Multicast Clouds

About the Sender Delay Option

About Configuring Carousel Passes

About the NACK Interval Multiplier

About the File Resend or Stop Feature

About Configuring Multicast Forward Error Correction

About Configuring Channel Options for Content Replication

Enabling Content Engines for Multicasting

Configuring Multicast Cloud Properties

Modifying a Multicast Cloud

Deleting Multicast Clouds

Viewing Multicast Clouds

Adding and Removing Receiver Content Engines

Configuring Channels for Multicast or Unicast Transmission

Assigning and Removing Multicast Clouds from Channels

Verifying the Multicast Configuration

Commands Related to Multicasting

Configuring the ACNS Network for Content Distribution

Once the hardware devices that make up your ACNS network are properly installed and registered, you are ready to use the information contained in this chapter to organize those devices into an ACNS network that is capable of serving pre-positioned or live media to end users.

In the ACNS network, content is replicated through a channel distribution architecture. Content in channels can be transmitted by unicast pull or, if multicasting is enabled, by multicast push. This chapter provides information about configuring the network elements for channel distribution and multicasting. It contains the following sections:

•Preparing for Channel Distribution of Content

•Channel Routing Algorithm

•Preparing for Multicasting

Preparing for Channel Distribution of Content

Channel distribution describes the manner in which content is distributed from the origin web server to all the Content Engines that are subscribed to the content, or more specifically, assigned to the channel that represents that group of content objects. (For an overview of the channel distribution architecture, see the "Content Acquisition and Distribution Architecture" section.)

In preparing for channel distribution of content, you should configure the following network elements in the order presented in this section:

1. Locations—Creating and Modifying Locations

2. Content providers—Creating and Modifying Content Providers

3. Websites—Creating and Modifying Websites

4. Channels—Creating and Modifying Channels

Creating and Modifying Locations

Locations are set up in the Content Distribution Manager GUI, and they organize and group Content Engines into virtual networks for distribution of content through channels.

Locations need to be configured before you can activate Content Engines and Content Routers and bring them online in the ACNS network.

To create a new location or modify an existing one, follow these steps:

Step 1 From the Content Distribution Manager GUI, choose Network > Locations.

The Locations window appears. (See Figure 5-1.)

Figure 5-1 Locations Window

Step 2 Click the Create New Location icon in the taskbar. The Creating New Location window appears. (See Figure 5-2.)

Figure 5-2 Creating New Location Window

Step 3 Enter a location name in the Name field.

Note Fields marked with an asterisk are required.

Step 4 Choose a parent location (or choose None) from the Parent Location drop-down list.

A location with no parent location assigned is a level 1 location. A location with a level 1 parent becomes a level 2 location, and so forth. The location level is displayed after you choose a parent location (or choose None) and click Submit to save the configuration.

Step 5 If you wish, enter comments about the location in the Comments field. This step is optional.

Step 6 Click Submit.

Step 7 To modify a location, go to the Locations window and click the Edit icon next to the name of the location you want to modify.

Step 8 Change the location name, parent location, or description as needed and click Submit to save the changes.

Deleting Locations

You can delete locations as needed, as long as they are not the root locations of activated Content Engines or Content Routers.

Note If a location has a Content Engine or Content Router assigned to it, you can first assign the Content Engine or Content Router to another location and then delete the original location.

To delete a location, follow these steps:

Step 1 From the Content Distribution Manager GUI, choose Network > Locations. The Locations window appears.

Step 2 Click the Edit icon next to the location that you want to delete.

The Modifying Location window appears.

Step 3 Click the Trash icon. You are asked to confirm your decision to delete the location.

Step 4 Click OK. The location is deleted.

Viewing the Location Tree

The location tree represents the network topology you configured when you assigned a parent to each location. The Content Distribution Manager GUI graphically displays the relationships between the locations configured in your ACNS network.

To view the location tree, choose Network > Location Trees. The location tree is displayed. Figure 5-3 shows an example of a location tree display.

Figure 5-3 Location Tree Display

Creating and Modifying Content Providers

The Content Distribution Manager GUI allows you to create a content provider directory that lists the name and contact information for each of your content providers. You need to create at least one content provider listing before you can create a directory of content providers' websites. Both content providers and websites must be set up in your ACNS network before you can create channels.

You can create or modify a content provider by entering or changing the company name and address, the primary contact information, or the optional secondary contact information.

To create or modify a content provider, follow these steps:

Step 1 From the Content Distribution Manager GUI, choose Channels > Content Provider.

The Content Providers window appears.

Step 2 Click the Create New Content Provider icon in the taskbar. The Creating New Content Provider window appears.

Step 3 Enter the company name. You also have the option to enter the address and contact information.

Step 4 Click Submit.

Step 5 To modify a content provider, go to the Content Providers window and click the Edit icon next to the content provider name that you want to modify.

The Modifying Content Provider window appears. (See Figure 5-4.)

Figure 5-4 Modifying Content Provider Window

Step 6 Enter any changes you want to make to the company name and address, the primary contact information, or the optional secondary contact information.

Note Clicking Cancel returns you to the Content Providers window.

Step 7 Click Submit.

Deleting Content Providers

You can delete content providers as needed.

Note When you delete a content provider, all websites and channels that have been added for the content provider are also deleted.

To delete a content provider, follow these steps:

Step 1 From the Content Distribution Manager GUI, choose Channels > Content Provider.

Step 2 Click the Edit icon next to the content provider name that you want to delete.

The Modifying Content Provider window appears. (See Figure 5-4.)

Step 3 Click the Trash icon. You are prompted to confirm your decision.

Step 4 Click OK to execute your request.

Viewing Content Providers

To view content providers, follow these steps:

Step 1 From the Content Distribution Manager GUI, choose Channels > Content Provider.

The Content Providers window appears, displaying a list of all the Content Providers in your ACNS network. (See Figure 5-5.)

Figure 5-5 Content Providers Window

Step 2 To sort the display table by primary contact, phone number, or e-mail address, click the respective column heading.

Step 3 To print the table, click the Printer icon.

Creating and Modifying Websites

The Content Distribution Manager GUI allows you to create a directory that lists all the websites in your ACNS network. A website listing must have a content provider, and must provide the URL for the origin web server that stores the website content.

Both websites and content providers must be set up in your ACNS network before you can create channels. Channels then map the website content to the Content Engines in your ACNS network.

To create or modify a website, follow these steps:

Step 1 From the Content Distribution Manager GUI, choose Channels > Web Sites.

The Web Sites window appears, displaying a list of the websites on your ACNS network. You can choose to display 10, 20, 40, or ALL websites from the Rows drop-down list.

Step 2 To create a new website, click the Create New Web Site icon in the taskbar. The Creating New Web Site window appears.

Figure 5-6 Creating New Web Site Window

Step 3 Enter the name, content provider, and origin server for the website. (See Table 5-1 for a description of website properties.)

Note You must configure your content providers before you create a website.

Step 4 If you wish, choose a WMT authentication type from the WMT Authentication Type drop-down list. This step is optional.

Note This setting must match the setting on the origin server for the stream to play correctly.

Step 5 Check the Pure DNS Routing check box if you want to use only the DNS server specified in the incoming packets for DNS requests. This causes the DNS caching name service to determine the original destination IP address.

Table 5-1 Website Properties

Property

Description

Name*¹

Unique name for the website.

Content Provider*

Name of the company that is providing the content.

Note The content provider must be predefined in the Creating New Content Provider window. (See the "Creating and Modifying Content Providers" section.)

Origin Server*

Fully qualified domain name of the origin server where the content resides.

Request Routed FQDN

Fully qualified domain name to route requests.

WMT Authentication Type

Basic authentication or NTLM authentication.

Note This setting must match the setting on the origin server for the stream to play correctly.

Pure DNS Routing

When checked, uses only the DNS server specified in the incoming packets for DNS requests. This causes the DNS caching name service to determine the original destination IP address.

When unchecked (the default), allows the DNS caching name service to use the servers configured on the Content Engine and allows WCCP interception of DNS requests.

¹* = required field. All other fields are optional.

Step 6 Click Submit to save the configuration.

Step 7 To modify a website, go to the Web Sites window and click the Edit icon next to the name of the website that you want to modify. The Modifying Web Site window appears.

Step 8 Enter changes to the website data as needed.

Step 9 Click Submit to save the changes.

Deleting Websites

Note When you delete a website, all channels that have been added for the website are also deleted.

To delete a website, follow these steps:

Step 1 From the Content Distribution Manager GUI, choose Channels > Web Sites.

The Web Sites window appears, displaying a list of all websites on your ACNS network.

Step 2 Click the Edit icon next to the name of the website that you want to delete. The Modifying Web Site window appears.

Step 3 Click the Trash icon. You are prompted to confirm your decision.

Step 4 Click OK to execute your request.

Viewing Websites

To view the list of websites associated with content providers, follow these steps:

Step 1 From the Content Distribution Manager GUI, choose Channels > Web Sites.

The Web Sites window appears, displaying a list of all websites on your ACNS network.

Step 2 To sort the display table by website, FQDN, origin server, or content provider, click the respective column heading.

Step 3 To print the table, click the Printer icon.

Creating and Modifying Channels

Channels map the content from a website to the devices in your ACNS network. Before you can create a channel, you must first create a directory of your content providers and provide URLs to their websites. (See the "Creating and Modifying Content Providers" section and the "Creating and Modifying Websites" section.)

Using the Content Distribution Manager, you can create, modify, or remove channels from the ACNS network. Keep in mind that modifying channels can affect the availability of content on the ACNS network.

You create a channel by defining the following items:

•Name

•Content provider

•Website

•Manifest file

•Channel properties (channel priority, multicasting)

Creating a Channel

To create a channel, follow these steps:

Step 1 From the Content Distribution Manager GUI, choose Channels > Channels. The Channels window appears, listing all the channels in your ACNS network.

Step 2 Click the Create New Channel icon in the taskbar. The Creating New Channel window appears. (See Figure 5-7.)

Figure 5-7 Creating New Channel—Channel Properties

Step 3 Use the fields provided under the Channel Information heading to configure the channel name and website that the channel is associated with.

Step 4 Use the fields provided under the Acquisition and Distribution Properties heading to configure channel priority, enable multicasting, or disable encryption. (See Table 5-2 for a description of the channel properties fields. Required fields are indicated by an asterisk in the GUI and in Table 5-2.)

Table 5-2 Channel Properties

Property

Description

Channel information

Name*¹

Unique name for the channel.

Request Routed FQDN

Fully qualified domain name to route requests.

Origin Server

Fully qualified domain name of the origin server.

Content Provider*

Name of the content provider associated with this channel.

WebSite*

Name of the website belonging to the content provider that is associated with this channel. After you choose a content provider in the window, the window refreshes to display only websites belonging to that content provider.

Note The website must be predefined in the Creating New Web Site window.

Live Channel

When checked, creates a live channel to distribute live or scheduled programs to the Content Engines associated with this channel. This channel does not have a related manifest file and cannot be used to distribute file-based content as regular channels do. The live channel learns about a live program through a program file that describes the attributes of the program.

Checking this check box disables the fields in the Acquisition and Distribution Properties, Manifest, and Manifest Proxy Information.

Acquisition and Distribution Properties

Distribution Priority*

Content distribution priority setting. Options are High, Normal, and Low. The default is Normal.

Multicast only, Multicast/Unicast, or Unicast only*

Enables multicast-only, multicast transmission with failover to unicast, or unicast-only transmission.

See the "Multicast Distribution Overview" section.

Disable Encryption for Distribution

Disables encryption for distribution when checked.

¹* = required field. All other fields are optional.

Step 5 If you wish to add comments regarding the channel for the benefit of other Content Distribution Manager users, enter them in the Comments field provided.

Step 6 Click Submit to save the channel configuration.

Note To configure manifest file and manifest proxy information for a channel, see the "Configure Manifest File and Proxy Information for the Channel" section.

Modifying a Channel

To modify a channel, follow these steps:

Step 1 Choose Channels > Channels to get to the Channels window.

Step 2 Click the Edit icon next to the name of the channel that you want to change. The Modifying Channel window appears. (See Figure 5-8.)

Figure 5-8 Modifying Channel Window

Step 3 Make changes to the channel configuration as needed.

Note The information in the Content Provider and WebSite fields cannot be modified in this window; the parameters can be set only during the creation of a channel.

Step 4 Click Submit to effect any changes you have made to the channel configuration. The Content Distribution Manager updates the channel information.

After you create a new channel, you need to designate a root Content Engine for the channel and then assign Content Engines or device groups to the channel. Although designating a root Content Engine and assigning devices to the channel can be done from the same GUI window, the following sections break out these steps into separate procedures.

Designating the Root Content Engine

The root Content Engine is the one Content Engine that is authorized to go directly to the origin web server for content. The root Content Engine then publishes the content to other Content Engines in the channel. You must designate a root Content Engine for content distribution to take place.

To designate one Content Engine to be the root Content Engine for a channel, follow these steps:

Step 1 From the Content Distribution Manager GUI, choose Channels > Channels.

Step 2 Click the Edit icon next to the name of the channel to which you want to assign a root Content Engine. The Modifying Channel window appears. (See Figure 5-8.)

Step 3 You can designate a root Content Engine when assigning device groups to the channel or when assigning Content Engines to the channel.

•In the Contents pane click Assign content engines. The Content Engines Assigned to Channel window appears. Click the name of a location, or choose all locations and proceed to Step 4.

•Alternatively, click Assign device groups. The Device Groups Assigned to Channel window appears. Check the check box next to the name of a device group and proceed to Step 4.

Step 4 Choose a Content Engine from the Root CE drop-down list. The list contains all of the Content Engines currently assigned to the channel in which you are working.

Note If there are no Content Engines or device groups assigned to the channel, no choices appear in the Root CE drop-down list.

Step 5 Click Submit.

Adding and Removing Content Engines from Channels

To add or remove Content Engines from a channel, follow these steps:

Step 1 From the Content Distribution Manager GUI, choose Channels > Channels.

Step 2 Click the Edit icon next to the name of the channel that you want to change. The Modifying Channel window appears. (See Figure 5-8.)

Step 3 In the Contents pane, choose Assign content engines. The Content Engines assignment to Channel window appears, displaying the unreserved and total disk space in the cdnfs partition. Content Engines can be added to the channel from more than one location. A list of the Content Engines in all locations to which they have been assigned appears.

Step 4 Click the Assign icon (blue cross mark) next to the name of the Content Engine that you wish to associate with the channel. Alternatively, you can click the Assign all Content Engines icon in the taskbar to perform a bulk addition of all Content Engines in various locations to the channel.

Step 5 Click Submit to add the Content Engines to the channel. Upon submission, a green tick mark appears next to the assigned Content Engine.

Step 6 To remove Content Engines, click the Unassign icon (green tick mark) next to the name of the Content Engine that you want to remove from the channel. Alternatively, you can click the Unassign all Content Engines icon in the taskbar to perform a bulk removal of all Content Engines from the selected channel.

Step 7 Click Submit to remove the Content Engines from the channel. The list of Content Engines in the channel shows a blue cross mark next to the name of the removed Content Engine.

If the Content Engine that you removed was the root Content Engine, and if there is at least one Content Engine still assigned to the channel, you must designate a new root Content Engine. (See the "Designating the Root Content Engine" section.)

Adding and Removing Device Groups from Channels

Device groups are assigned to channels through the Content Distribution Manager GUI. Whenever a channel is created and additional device groups are added, or a channel assignment to the device group changes, devices in the group are notified of their assignment to the associated channel.

The relationship between device groups and channels is many-to-many. A channel can have multiple device groups and device groups in turn can belong to multiple channels.

To add or remove a device group from a channel, follow these steps.

Note When a device group is removed from a channel, the Content Engines that were part of the device group are also removed from the channel. When a device is removed from a device group containing the original channel assignment, this device is also unassigned from channels. Similarly, when a channel is removed from a device group, the associated devices are also unassigned.

Step 1 From the Content Distribution Manager GUI, choose Channels > Channels.

Step 2 Click the Edit icon next to the name of the channel to which you want to assign a device group or from which you want to remove a device group. The Modifying Channel window appears. (See Figure 5-8.)

Step 3 In the Contents pane, choose Assign device groups. The Device Group assignment to Channel window appears, displaying the minimum unreserved disk space in the cdnfs partition. An asterisk (*) under the Note column denotes that there is no free space available to be assigned to this channel. A double asterisk (**) under the Note column denotes that Content Engines associated with this device group have been already assigned to this channel.

Step 4 Click the Assign icon (blue cross mark) next to the name of the device group that you wish to associate with the channel. A green tick mark appears next to the assigned device group on submission. Alternatively, you can click the Assign all Device Groups icon in the taskbar to perform a bulk addition of all device groups in various locations to the channel.

Step 5 Click Submit to add the device groups to the channel.

Step 6 To remove device groups, click the Unassign icon (green tick mark) next to the name of the device group that you want to remove from the channel. Alternatively, you can click the Unassign all Device Groups icon in the taskbar to perform a bulk removal of all device groups from the selected channel.

Step 7 Click Submit to remove the device groups from the channel. The browser window refreshes, listing the updated channels with a blue cross mark next to the unassigned device groups.

Updating Channel Content

At any point after you have replicated content to the Content Engines that are associated with your channel, you can update that content using the fetch manifest feature. For example, if you modify your manifest file to point to new content or remove references to content that you want to make obsolete, you must fetch the manifest file to begin replication of any new channel content, and to sever connections to content that you want to make obsolete.

Note Content that is removed from the manifest file is made unavailable as soon as that updated manifest file is fetched. Obsolete content is not immediately deleted from the channel cache but is eventually removed to make room for new channel content.

To fetch a new or updated manifest file, follow these steps:

Step 1 From the Content Distribution Manager GUI, choose Channels > Channels.

Step 2 Click the Edit icon next to the name of the channel to open your channel for editing.

Step 3 Verify that the Manifest URL field points to the correct manifest file for the channel.

Step 4 Click the Fetch Manifest icon in the taskbar. You are prompted to confirm your decision.

Step 5 Click OK to execute your request.

Step 6 Click OK.

To force the replication of channel content and refresh the information, follow these steps:

Step 1 From the Content Distribution Manager GUI, choose Channels > Channels.

Step 2 Click the Edit icon next to the name of the channel that you want to modify to open your channel for editing.

Step 3 In the Contents pane, click Replication Status. The Channel Replication Status window appears.

Step 4 Click the Force Replication icon in the taskbar. You are prompted to confirm your decision.

Step 5 Click OK. You are notified that your request has been sent and prompted to check back in a few minutes.

Step 6 Click OK. After a time, the Channel Replication Status window refreshes.

For a description of the channel replication status data, see the "Monitoring Replication Status" section.

Deleting Channels

To delete a channel, follow these steps:

Step 1 From the Content Distribution Manager GUI, choose Channels > Channels.

Step 2 Click the Edit icon next to the name of the channel that you want to delete. The Modifying Channel window appears. (See Figure 5-8.)

Step 3 Click the Trash icon. You are prompted to confirm your decision to delete the channel.

Step 4 Click OK to confirm your decision. The channel is removed from the ACNS network.

Viewing Channels

To view all channels across your ACNS network, follow these steps:

Step 1 From the Content Distribution Manager GUI, choose Channels > Channels.

The Channels window appears, listing all the channels in your ACNS network. (See Figure 5-9.)

Figure 5-9 Channels Window

The website and the content provider that are associated with each channel are listed in the row for the channel.

Step 2 To sort the channels by website or by content provider, click the respective column heading.

Step 3 To print the channel display table, click the Printer icon.

Viewing All Content Engines Assigned to a Channel

In the Content Distribution Manager GUI, a distinction is made between devices that are assigned directly to a channel or devices that are assigned through a device group. If the device is assigned directly as well as through a device group, the assignments are tracked separately. For tracking purposes, the View all Content Engines assigned to Channel window displays all Content Engines assigned to a channel, regardless of whether they are assigned directly or through device groups.

To view the list of all Content Engines assigned to a channel, follow these steps:

Step 1 From the Content Distribution Manager GUI, choose Channels > Channels.

Step 2 Click the Edit icon next to the name of the channel that you want to view. The Modifying Channel window appears.

Step 3 In the Contents pane, choose List all assigned content engines. The View all Content Engines assigned to Channel window appears and lists all Content Engines assigned to the specified channel. (See Figure 5-10.)

Figure 5-10 View All Content Engines Assigned to Channel Window

Table 5-3 describes the information that is displayed in this window.

.

Table 5-3 Content Engine Channel Assignment Information

Column Heading

Description

Content Engine

Name of the Content Engine assigned to the channel.

Directly Assigned

Indicates whether the Content Engine was assigned directly to the channel (yes or no).

Assigned through device group

Indicates whether the Content Engine was assigned through a device group. If yes, then this column displays the name of the device group. If no, then this column displays the value Not Applicable (n/a).

Channel Routing Algorithm

To distribute content through unicast, the ACNS network automatically creates a unidirectional distribution tree for each channel. The root node of the tree is the root Content Engine of the channel, and each Content Engine subscribed to the channel is a node on the tree.

Content objects are distributed along the edges of the tree in a store-and-forward manner. For each node, its parent node is also called its forwarder Content Engine. The algorithm for automatically designating the forwarder Content Engine is called the channel routing algorithm.

Three general rules in the current channel routing algorithm are as follows:

1. In each location for each channel, only one Content Engine fetches content from another location for that channel. We call this Content Engine the location leader of the channel. All other Content Engines in this location use the location leader as the forwarder for this channel. Note that within one location, different channels may have different location leaders.

Currently, the location leader can only be computed automatically by the channel routing algorithm. You can use the show distribution channel command to see which Content Engine is the current forwarder for a channel. Or, you can use the show distribution forwarder-list command to see the forwarder selection order of a Content Engine for a channel.

2. The location leader finds a subscribed Content Engine from the closest location on the path toward the root Content Engine as its forwarder.

3. If the location leader Content Engine fails for some time, another Content Engine in the location takes over as the location leader. If the root Content Engine fails, another Content Engine in the location takes over as the temporary root Content Engine.

Preparing for Multicasting

Multicasting allows efficient distribution of content to multiple Content Engines and is useful when many end users are interested in the same content. ACNS software supports Pragmatic General Multicast (PGM)-based multicast replication using either satellite or multicast-enabled terrestrial infrastructures.

To prepare for multicast transmission of content, you should perform these tasks in the order presented in this section:

1. Enabling Content Engines for Multicasting

2. Configuring Multicast Cloud Properties

3. Adding and Removing Receiver Content Engines

4. Configuring Channels for Multicast or Unicast Transmission

5. Assigning and Removing Multicast Clouds from Channels

Multicast Distribution Overview

Once content is acquired from the origin server by the root Content Engine of a channel, it can be replicated through the channel either by unicast or multicast transmission. The basic channel distribution architecture provides for unicast content replication using a hop-by-hop store-and-forward methodology with the forwarder Content Engines systematically selected on the basis of the manually configured location hierarchy. When multicast transmission is desirable, channels and Content Engines can be enabled for multicasting.

About Multicast Clouds

For multicast content replication, Content Engines are grouped into multicast clouds. A multicast cloud consists of one sender Content Engine, an optional backup sender Content Engine, and at least one receiver Content Engine in a hub and spoke topology. All the Content Engines in one multicast cloud share a unique advertisement address that allows them to communicate multicast session information. The multicast cloud is then associated with one or more multicast-enabled channels.

In pull-based unicast content distribution, a unicast receiver pulls file data out of the proper forwarder (or root Content Engine) when a client requests the content. By contrast, in multicast content distribution, the sender Content Engine in a multicast cloud proactively pushes content into the cloud according to a preconfigured schedule.

The receiver Content Engines listen on the advertisement IP address for information on content to be replicated from the sender and decide whether to accept an advertisement and hence whether to receive the content.

Content metadata must be distributed to a receiver first before the content itself can be replicated. Metadata is always distributed using unicast. Content, however, can be replicated using either multicast or unicast. Content metadata helps to define what content to retrieve, how content will be retrieved, how recently content has been updated, how content is to be pre-positioned (for example, expiration time), and so forth. A multicast receiver rejects the multicast sender's advertisement of a file if the proper content metadata has not yet arrived.

The Content Distribution Manager GUI allows you to configure multicast cloud parameters, such as on-demand carousel, metadata delay (Sender Delay in the GUI), available multicast-out bandwidth, and content priority, as Advanced Settings in the Creating New Multicast Cloud window. These parameters are discussed in the following sections.

About the Sender Delay Option

The sender delay option allows you to configure enough time for the metadata to propagate to the receiver, and thus avoid having the receiver reject the multicast sender's advertisement of a file. The multicast sender performs carousel passes only on-demand; that is, the sender retransmits files only as requested by the receiver Content Engine. The receiver Content Engine sends out periodic requests for files that it has not yet received. The sender delay parameter is used to configure an extra delay before an on-demand carousel pass can begin. When configuring the sender delay interval, you must take into account that the content metadata must first be propagated to the receiver before the multicast transmission can commence. You can configure the duration of the delay based on your expectation or best guess of the amount of time required for metadata to be propagated. The system takes this user-configured sender delay value and delays the multicast transmission by such a period.

About Configuring Carousel Passes

In ACNS 5.1 software, the carousel pass setting defines the maximum number of times that the sender can retransmit the multicast for missing files. The definition of a carousel pass in ACNS 5.1 software differs from the carousel pass configuration in ACNS 5.0 software. In ACNS 5.0 software, you configure the number of times that the sender will retransmit the multicast, regardless of whether files are missing or not missing. Thus, carousel passes in ACNS 5.0 software are performed as configured, whereas carousel passes in ACNS 5.1 software are performed on-demand after the first round.

In ACNS 5.1 software, individual multicast receiver Content Engines periodically ask again for those files that have not been received after the first carousel pass. The sender Content Engine transmits the missing files, and after all the receiver Content Engines have received all the multicast content, the sender stops transmitting content.

In the on-demand carousel feature, the multicast receiver periodically collects information for missing content and sends a negative acknowledgment (NACK) to the sender Content Engine identifying the missing content. The multicast sender sends out the requested content when it receives the NACK from the receiver.

In ACNS 5.1 software, you configure an upper limit of carousel passes (instead of a fixed number of carousel passes, as is the case in ACNS 5.0 software); the primary sender sends the first carousel pass without being triggered by a NACK, and subsequent passes only occur when the sender detects missing content.

If the primary sender fails and the backup sender becomes active, the backup sender takes charge of NACK processing. The backup sender's carousel passes are always triggered by a NACK. When the maximum number of carousel passes is reached for a file on the current active sender, you can configure file distribution to fall back to unicast, if this is desired. (See the "About Configuring Channel Options for Content Replication" section for more information.)

To adjust the pacing of the multicast transmission, you can specify how much time must elapse before missing files are resent (the Delay between passes field) in the Content Distribution Manager GUI Multicast Cloud Configuration window (Network > Multicast Clouds).

About the NACK Interval Multiplier

To identify missing content and trigger a resend of a file, receiver Content Engines send a negative acknowledgement (NACK) message to the sender Content Engine. NACK messages generated by many receiver Content Engines could generate more traffic than the sender can handle. ACNS 5.1 software allows you to adjust the average interval between NACKs by configuring a NACK interval multiplier for an individual receiver Content Engine. This value (an integer between 0.1 and 10) adjusts the default average NACK interval (the default is 20 minutes) by the value configured as the interval multiplier. For example, if you set the NACK interval multiplier to 3, the interval between NACKs becomes 20 minutes x 3, or 60 minutes.

This adjustment can be made as needed by choosing Devices > Content Engines > CDN Settings > Acquisition and Distribution Settings in the Content Distribution Manager GUI.

To send an immediate NACK request rather than wait for the scheduled interval, you can issue the distribution multicast send-nack-now EXEC command on a multicast receiver Content Engine.

To configure the NACK interval multiplier, follow these steps:

Step 1 In the Content Distribution Manager GUI, choose Devices > Content Engines.

Step 2 Click the Edit icon next to the name of the Content Engine you want to configure.

Step 3 In the Content pane choose CDN Settings > Acquisition and Distribution Settings. The Acquisition and Distribution Settings for Content Engine window appears. (See Figure 5-11.)

Figure 5-11 Acquisition and Distribution Settings

Step 4 Click and drag the Content NACK Interval Multiplier slider control across the calibrated ruler to adjust the interval between NACK messages. The scale ranges from 10 percent of normal to 10 times normal. The center of the scale corresponding to "normal" denotes the default value of 20 minutes. The value corresponding to the position of the slider is displayed in the field next to it.

Step 5 Click Submit to save your settings.

About the File Resend or Stop Feature

To trigger resending of a particular file, a particular channel, or all channels, you can issue the distribution multicast resend EXEC CLI command on a multicast sender. This command internally resets the number of carousel passes completed to zero for the desired target. Because the first resend of content always happens automatically without being triggered by a NACK, setting the carousel pass count to zero triggers a resend of the content. However, if the on-demand-only option is additionally specified, the first carousel pass made after the command has been issued can only be triggered by a NACK for the content involved.

To stop sending a particular file, a particular channel, or all channels, you can issue the distribution multicast stop EXEC command on a multicast sender. This command internally increases the number of carousels completed to the maximum integer. This prevents further carousel passes from being triggered.

About Configuring Multicast Forward Error Correction

Forward error correction (FEC) is a type of data encoding that protects transmissions against errors, without requiring retransmission. The FEC number denotes the number of packets that will be encoded into one FEC transmission group. The higher the FEC number, the bigger the transmission group size, and hence the more error-resistant the multicast may be, but also the more computational overhead there will be on the multicast sender and receivers. Note that there is no bandwidth overhead related to FEC.

In ACNS 5.0.1 software, the FEC default value is 8, whereas in ACNS 5.0.3 software and later, the FEC default is 16. If the multicast sender device is a high-end Content Engine model such as a CE-7325, you can set this number higher in order to improve multicast reliability, especially when your network connectivity has a high uniform loss rate. However, we do not recommend that you set this number beyond 64 because it may place too much of a load on all the receiver Content Engines.

Separately, you can also set proactive FEC using the PGM config file (a text file accessible from the Content Engine CLI in the /local1/multicast-expert-config/ directory). Proactive FEC is the number of extra packets that the multicast sender proactively sends out for every FEC number of data packets. The proactive FEC default value is 0. You can set it higher for better multicast reliability, for example, 2 proactive packets for every 16 FEC packets, at the expense of 12.5 percent traffic overhead (2 divided by 16).

Proactive FEC is an additional reliability measure above and beyond that of normal FEC. Although normal FEC does not incur bandwidth overhead, proactive FEC does. Proactive FEC primarily protects the multicast from uniform losses. For example, if the network has a uniform loss rate of 15 percent, then a proactive FEC of 2 extra packets for every 16 FEC packets (a 12.5 percent bandwidth overhead) cuts the effective loss rate down to 2.5 percent. Most network losses are not completely uniform. Still, during bursts, proactive FEC similarly undercuts the effective burst loss rate. For example, if the burst loss rate is 20 percent while the average loss rate is 2 percent, with proactive FEC at 12.5 percent, the receiver Content Engines experience a burst loss rate of 7.5 percent and an average loss rate near 0 percent.

About Configuring Channel Options for Content Replication

Once a multicast cloud is configured, it must be associated with one or more multicast-enabled channels for multicast replication of content to take place within the channel. The channel configuration offers various transmission options for replicating content; a channel can be configured for multicast and unicast (multicast with failover to unicast), multicast-only, or unicast-only transmission.

Multicast and Unicast

When a channel is configured for multicast and unicast, the receiver Content Engine uses unicast to download content only after all carousel passes have been exhausted and after the preconfigured multicast transmission fails. In a multicast cloud configuration that uses a backup sender, when the channel is enabled for multicast and unicast, the failover to unicast occurs when the current active multicast sender has exhausted all the carousel passes for the file.

If the administrator wants the Content Engines to fall back to unicast (for example, with a multitier unicast deployment using a terrestrial multicast medium), the multicast cloud should be configured for a low number of carousel passes (such as 1, 2, or 3).

Multicast Only

However, if only multicast replication is desired (for example, with a hub and spoke or star topology deployment using a satellite multicast medium), the channels should be configured as multicast-only, with a high number of carousel passes configured in the multicast cloud (such as 10 or more).

When a channel is configured to be multicast only (that is, when the channels are associated with a multicast cloud and the subscribing receiver Content Engine has multicast service successfully licensed and enabled), content replication takes place only through multicasting. No retransmission takes place in unicast at all. This prevents background unicast polls from happening and taking up bandwidth. However, if a Content Engine in the multicast-only channel is not licensed and enabled for multicasting, it can continue to request all the content from a multicast-only channel through unicasting.

Enabling Content Engines for Multicasting

Before you can create a multicast cloud, you must have a multicast distribution license key (purchased from Cisco Systems) and Content Engines that are enabled for multicasting. These multicast-enabled Content Engines can then be assigned as sender and receiver Content Engines when you configure the multicast cloud.

Content Engines for multicasting must be assigned to the multicast cloud, which in turn is assigned to multicast-enabled channels. Also, you need to subscribe individual Content Engine senders and receivers of the cloud to the particular multicast-enabled channel. You must do this additional step even though the multicast cloud is associated with the channel.

To enable Content Engines for multicasting, follow these steps:

Step 1 From the Content Distribution Manager GUI, choose Devices > Content Engines.

Step 2 Click the Edit icon next to the name of the Content Engine that you want to enable for multicasting. The Modifying Content Engine window appears.

Step 3 In the Contents pane, choose CDN Settings > Multicast Distribution License. The Multicast Distribution License Agreement window appears.

The Multicast Distribution Agreement for Content Engine window appears only if you have not read and accepted the multicast distribution license for the device. To accept the license, follow these steps:

a. Read the terms of this agreement.

b. Check the Accept License check box

c. Click Submit.

The window refreshes itself and the Multicast Distribution License Settings for Content Engine window appears.

Step 4 Check the Enable check box, and enter the license key in the License Key field.

Alternatively, check the Evaluate check box to enable an evaluation license key for a set period.

Step 5 Click Submit.

Step 6 Return to the Modifying Content Engine window and repeat Step 1 through Step 5 to enable multicasting on other Content Engines in your ACNS network.

Step 7 To modify or delete the multicast distribution license settings, you have the following options:

•To delete the configured settings for the device, click the Remove Device Settings icon in the taskbar.

•To apply the factory default settings for the device, click the Apply Defaults icon in the taskbar.

•To override the device group settings that have been applied from device groups to which the device is associated, click the Override Group Settings icon in the taskbar.

When a device is associated with one or many device groups that have been configured with the settings displayed in this window, you can choose the device group name from the drop-down list whose settings you want to apply to the device.

Step 8 Proceed to the next section, "Configuring Multicast Cloud Properties," to create a multicast cloud.

Configuring Multicast Cloud Properties

A multicast cloud is configured by specifying an IP multicast address for advertising the data being transferred, an IP multicast address range for transferring the data, a primary multicast sender Content Engine and an optional backup sender, a set of receiver Content Engines, and a maximum rate at which to send the data.

Note We highly recommend that you avoid using multicast addresses of the form x.0.0.y (for example, 238.0.0.1). These addresses hash to the same Ethernet address space as 224.0.0.x, which is used frequently by routers and switches for local multicasts. Additional traffic on these addresses adds to the workload of these network elements.

To configure a multicast cloud, follow these steps:

Step 1 From the Content Distribution Manager GUI, choose Network > Multicast Clouds. The Multicast Clouds window appears.

Step 2 Click the Create New Multicast Cloud icon in the taskbar. The Creating New Multicast Cloud window appears. (See Figure 5-12.) See Table 5-4 for a description of multicast cloud parameters.

Figure 5-12 Creating New Multicast Cloud Window

Note Figure 5-12 does not display all the fields in the window. To view all the fields in the Content Distribution Manager GUI, you must scroll to the bottom of the window.

Step 3 Configure the basic multicast cloud information:

a. Enter a name for the multicast cloud in the Name field.

b. Enter an advertisement address in the Advertisement IP address field.

When creating the multicast cloud, you must assign a unique advertisement address. This provides all the Content Engines in one cloud with the same advertisement address and allows them to communicate multicast session information.

c. Enter a port number in the Port field. This is the port used by file transfer addresses. The default port is 7777.

Step 4 Configure the multicast sender and backup sender.

a. Choose a primary sender Content Engine from the Available Sender CEs list and click the Update Primary Sender CE button. The name of Content Engine appears in the Primary Sender CE field.

b. If you wish, choose a backup sender Content Engine from the Available Sender CEs list and click the Update Backup Sender CE button. The name of Content Engine appears in the Backup Sender CE field.

Step 5 Configure the multicast address settings:

a. Enter a start IP address and an end IP address in the fields provided.

Once the multicast cloud is configured and you associate the multicast cloud with one or more multicast-enabled channels, this multicast address range is used to provide each channel associated with it a unique data channel multicast address. When you assign a channel to the multicast cloud, an unused IP address is automatically selected from this range to ensure that the address is used by only one channel and by only one multicast cloud.

b. Enter a maximum multicast rate in kilobits per second (kbps) in the Default Multicast-out Bandwidth field. This value applies to the sender Content Engine.

Step 6 Configure the multicast cloud advanced settings as necessary:

a. Based on your means of transmitting the multicast, choose either Satellite or Terrestrial from the Multicast medium drop-down list.

b. Enter the number of hops for Time To Live in the IP TTL field.

The TTL field dictates how many hops a packet travels before it is discarded, regardless of whether or not the packet has reached its destination.

c. Enter the number of carousel passes in the # of Carousel passes field.

This is the maximum number of times that a multicast sender can send the content of the channel to which it is assigned. The multicast sender can be set to fall back to unicast after the carousel pass is completed.

If you want the Content Engines to fall back to unicast (for example, with a multitier unicast deployment using a terrestrial multicast medium), the multicast cloud should be configured for a low number of carousel passes (such as 1, 2, or 3).

However, if multicast replication is preferred (for example, with a hub and spoke or star topology deployment using a satellite multicast medium), use a high number of carousel passes, such as 10 or more.

Note If a channel is set to multicast only and the receiver is multicast-ready, the maximum number of configurable carousel passes is 1,000,000,000. If the number of carousel passes configured is used up, the syslog displays a warning message as an alert.

d. Choose a value for the FEC transmission group from the drop-down list.

FEC data encoding protects transmissions against errors, without requiring retransmission. The FEC number denotes the number of packets that will be encoded into one FEC transmission group. The higher the number, the bigger the transmission group size, and hence, the more error-resistant the multicast may be, but also the more computational overhead there will be on the multicast sender and receivers. Note that there is no bandwidth overhead related to FEC.

e. Enter a value, in minutes, for the Delay between passes field. This sets the interval between file transmissions.

f. To enable the IP router alert option for Pragmatic Group Multicasting (PGM) packets, check the PGM Router-assist check box.

This option specifies whether IP routers are to be used to assist in distribution of content.

g. Enter a value, in minutes, for the Primary-to-backup failover grace period. The range is 5 to 7200 minutes. The default is 30 minutes.

This is the amount of time allotted for the backup sender to detect whether the primary sender is active.

h. Enter a value, in minutes, for the Backup-to-primary fallback grace period. The range is 5 to 7200 minutes. The default is 30 minutes.

This is the amount of time allotted for the primary sender to detect whether the backup is active.

Step 7 Enter any comments in the Comments field. This field is optional.

Step 8 Click Submit to save the configuration.

Your multicast cloud configuration is saved, and you can proceed to Step 3 in the "Adding and Removing Receiver Content Engines" section.

Note If you have not assigned any receiver Content Engines, a message appears, stating that your transaction is not complete until you assign receiver Content Engines to the multicast cloud.

Table 5-4 describes the parameters that you need to define in the Content Distribution Manager GUI when configuring a multicast cloud. Required fields are marked with an asterisk in the GUI and in the table.

Table 5-4 Multicast Cloud Parameters

Field

Description

Multicast Cloud Information

Name*¹

Identifier for the multicast cloud. The name must be unique across the system.

Advertisement IP address*

Multicast address collectively known and used by a multicast cloud to implement a communication channel.

The advertisement IP address must conform to these guidelines:

•It must be unique across the system.

•Each multicast cloud must have one advertisement address.

•It cannot be used in another multicast cloud.

•It must be within the RFC multicast range (224.0.0.0-239.255.255.255).

•It must not be within the start and end range specified by this cloud.

•It must not be any user-specified multicast address for programs.

•It must not be within the program multicast pool start and end range (as defined in System > Program Addresses).

See "IP Multicasting," for information on multicast address restrictions.

Port*

Port used for file addresses. The default port is 7777.

Multicast Address Sender

Primary Sender CE*

Primary Content Engine forwarder that pushes content to a set of Content Engine receivers using multicast.

Primary senders must conform to the following rules:

•The primary sender cannot be the backup sender for the same cloud.

•The primary sender cannot be the receiver for the same cloud.

•The primary sender cannot be the primary sender for a different cloud.

•The primary sender cannot be the backup sender for a different cloud.

A sender Content Engine cannot be deleted from the network. Before deleting a sender Content Engine, you must choose another Content Engine as the sender for the multicast cloud.

Backup Sender CE

Content Engine configured for backup in the event of failure of the primary sender Content Engine. The backup sender Content Engine uses the same multicast-out bandwidth value as the primary sender.

Backup senders must conform to the following rules:

•The backup sender cannot be the primary sender for the same cloud.

•The backup sender cannot be the receiver for the same cloud.

•The backup sender cannot be the primary sender for a different cloud.

•The backup sender cannot be the backup sender for a different cloud.

The primary and backup senders of a multicast cloud should subscribe to the same set of multicast-enabled channels as enforced by the Content Distribution Manager GUI.

Multicast Address Settings

Start IP address*

Start of the IP address range, which must be within the range 224.0.0.0 to 239.255.255.255.

The IP address range must conform to the following:

•The IP address range cannot overlap with program multicast pool addresses.

•The IP address range must contain all multicast addresses used by this cloud with its associated channel.

Note The IP address range in one multicast cloud can overlap that of another multicast cloud. A message alerts you that there is an overlap, but allows the operation. See "IP Multicasting," for information on multicast address restrictions.

End IP address*

End of the IP address range, which must be higher than the start IP address. The end IP address must be within the range 224.0.0.0 to 239.255.255.255.

See "IP Multicasting," for information on multicast address restrictions.

Default Multicast-out Bandwidth*

Maximum multicast rate in kilobits per second (kbps). The minimum rate is 10 kbps.

This is the default multicast-out bandwidth, which is applied 24 hours a day, 7 days a week. The multicast-out bandwidth is associated with the sender Content Engine only.

To customize bandwidth rates for different days, use the A&D Bandwidth Settings window. These settings override the default for period that you specify. (See the "Configuring Acquisition and Distribution Bandwidth Settings for Scheduled Times" section.)

Note Time-of-day bandwidth settings for multicast-out are not supported, with the exception of setting them to zero (0).

Multicast-out bandwidth settings are used by both primary and back up senders, if a back up sender is configured.

Advanced Settings

Multicast medium

Means of transmitting the multicast, either satellite or terrestrial. The default is satellite.

IP TTL

Time To Live expressed as the number of hops (1-255). The default is 255.

FEC transmission group

Size of an FEC (forward error correction) block in packets. (Refer to RFC 3208 PGM Reliable Transport Protocol Specification for more information.) The allowable inputs are 2, 4, 8, 16, 32, 64, and 128. The default is 16.

# of Carousel passes

Maximum number of times (1-1000000000) that a multicast sender will attempt to send missing content for on-demand carousels. The default is 5.

Note If the multicast sender finishes the last carousel on an object at time t and the multicast sender receives a NACK within t+carousel_delay, the multicast sender starts the next carousel of this object at time t+carousel_delay. That is, the multicast carousel is not triggered immediately upon receipt of the NACK, if the carousel delay is greater than zero (0).

Delay between passes

Delay between file transmissions, in minutes (0-10080) (7 days * 24 hours * 60 minutes). The default is 0 minutes.

PGM Router-assist

Specifies whether IP routers are to be used to assist in distribution of content. Checking this check box enables the IP router alert option for PGM packets.

Note PGM packet routing is supported in Cisco IOS 12.0(5)T and later 12.0 T releases.

Primary-to-backup failover grace period

Amount of time allotted for the backup sender to detect whether the primary sender is active. If the backup sender does not hear a heartbeat from the primary sender within this grace period, the backup sender assumes the active role.

The range is 5-7200 minutes. The default is 30 minutes.

Backup-to-primary fallback grace period

Amount of time allotted for the primary sender to detect whether the backup is active. If the backup sender does not respond within this grace period, the primary sender assumes the active role.

The range is 5-7200 minutes. The default is 30 minutes.

Comments

Comments about the multicast cloud.

¹* = required field. All other fields are optional.

Modifying a Multicast Cloud

To modify a multicast cloud, follow these steps:

Step 1 From the Content Distribution Manager GUI, choose Network > Multicast Clouds.

The Multicast Clouds window appears.

Step 2 Click the Edit icon next to the name of the multicast cloud that you want to change.

The Modifying Multicast Cloud window appears.

Step 3 Edit the information or settings as needed.

Step 4 Click Submit to save the changes.

Deleting Multicast Clouds

To delete a multicast cloud, follow these steps:

Step 1 From the Content Distribution Manager GUI, choose Network > Multicast Clouds. The Multicast Clouds window appears.

Step 2 Click the Edit icon next to the name of the multicast cloud that you want to delete. The Modifying Multicast Cloud window appears.

Step 3 Click the Trash icon in the taskbar. You are prompted to confirm your action.

Step 4 Click OK. The multicast cloud is deleted.

Viewing Multicast Clouds

To view a list of all the multicast clouds configured in your network, follow these steps:

Step 1 From the Content Distribution Manager GUI, choose Network > Multicast Clouds. The Multicast Clouds window appears, listing all the multicast clouds in your ACNS network.

The table also displays the sender Content Engine for each multicast cloud.

Step 2 To print the table data, click the Printer icon.

Adding and Removing Receiver Content Engines

Note Content Engines must be multicast-enabled with the multicast distribution license before you can add them to a multicast cloud. (See the "Enabling Content Engines for Multicasting" section.)

To create a functional multicast cloud, you must add at least one receiver Content Engine. Use the following guidelines when adding receiver Content Engines:

•You must choose at least one Content Engine to be a receiver.

•The maximum number of receivers you can add is the total number of Content Engines in the system (excluding the sender Content Engine).

•The receiver cannot be a receiver in another multicast cloud.

•The receiver cannot be a sender in the same multicast cloud. Only Content Engines that are not assigned to another multicast cloud are displayed as selections in the Content Distribution Manager GUI.

•Only a fully configured multicast cloud (with at least one receiver Content Engine) can be associated with a channel to enable the multicast capability.

•The list of Content Engines for selection is sorted by location. You can choose individual Content Engines from one or more locations to add to this multicast cloud.

Note Only Content Engines that are not assigned as receiver Content Engines to another multicast cloud or as sender Content Engines to this cloud are displayed as selections in the Content Distribution Manager GUI.

To add receiver Content Engines to a multicast cloud, follow these steps:

Step 1 From the Content Distribution Manager GUI, choose Network > Multicast Clouds. The Multicast Clouds window appears.

Step 2 Click the Edit icon next to the name of the multicast cloud to which you want to add receiver Content Engines. The Modifying Multicast Cloud window appears.

Step 3 In the Contents pane, click Assign receiver CEs. The Assigning Receiver CEs to Multicast Cloud window appears.

Step 4 To add one of the Content Engines in the list to the multicast cloud, click the Assign icon (blue cross mark) next to the name of the Content Engine that you want to add. Alternatively, you can click the Assign all Content Engines icon in the taskbar to perform a bulk addition of all Content Engines in various locations to the multicast cloud.

Note Note: The Content Distribution Manager GUI allows you to assign Content Engines that are not multicast enabled. However, you must ensure that any Content Engine that you assign to a multicast cloud must be multicast enabled with a multicast license. (See "Enabling Content Engines for Multicasting" section.)

Step 5 Click Submit. You should see the message "Change Submitted" in the Message bar to the left of the Submit button. Upon submission, a green tick mark appears next to the assigned Content Engine.

Step 6 To remove a Content Engine from the multicast cloud, click the Unassign icon next to the name of the Content Engine that you want to remove. Alternatively, you can click the Unassign all Content Engines icon in the taskbar to perform a bulk removal of all Content Engines in various locations from the multicast cloud.

Step 7 Click Submit to remove the Content Engines from the multicast cloud. Upon submission, a blue cross mark appears next to the unassigned Content Engine.

Configuring Channels for Multicast or Unicast Transmission

Cisco ACNS 5.1 software allows you to configure channels for multicast-only, multicast transmission with failover to unicast, or unicast-only transmission.

To configure a channel for multicast or unicast transmission, follow these steps:

Step 1 From the Content Distribution Manager GUI, choose Channels > Channels. The Channels window appears (see Figure 5-9), listing all the channels in your ACNS network.

Step 2 Click the Create New Channel icon in the taskbar. The Creating New Channel window appears. Alternatively, to enable an existing channel for multicasting, click the Edit icon next to the name of the channel that you want to modify.

Step 3 Use the fields provided under the Channel Information heading to configure or modify the channel properties. (See the "Creating and Modifying Channels" section.)

Step 4 Click the radio button for Multicast only, Multicast/Unicast, or Unicast only under the Acquisition and Distribution Properties heading to configure the channel for the proper transmission mode.

Step 5 Click Submit.

Assigning and Removing Multicast Clouds from Channels

You can assign or remove multicast clouds only from channels that are multicast-enabled. A channel is multicast-enabled when you click the Multicast/Unicast radio button or the Multicast-only radio button when you create or modify the channel. (See the "Creating and Modifying Channels" section.)

Note When a multicast cloud is assigned to a channel, the Content Engines that are part of the multicast cloud must also be individually assigned to the channel for multicasting. To assign Content Engines to a channel, follow the procedure in the "Adding and Removing Content Engines from Channels" section.

To assign or remove a multicast cloud from a multicast-enabled channel, follow these steps:

Step 1 From the Content Distribution Manager GUI, choose Channels > Channels. The Channels window appears (see Figure 5-9), listing all the channels in your ACNS network.

Step 2 Click the Edit icon next to the name of the channel to which you want to assign a multicast cloud or from which you want to remove a multicast cloud. The Modifying Channel window appears. (See Figure 5-8.)

Step 3 Enable multicasting on the channel, if you have not already done so.

a. Click the Multicast only or Multicast/Unicast radio button.

b. Click Submit.

Step 4 In the Contents pane, choose Assign Multicast Cloud. The Assigning Multicast Clouds to Channel window appears. (See Figure 5-13.)

Figure 5-13 Assigning Multicast Clouds to Channel Window

Step 5 Click the Assign Multicast Cloud to Channel icon in the taskbar. The Assign Multicast Cloud to Channel Assignment window appears.

Step 6 Choose a multicast cloud from the drop-down list. The window refreshes, showing the IP address range for that multicast cloud. In the IP address to use for this Channel field, enter any available IP address from this range to assign to this channel. (The first available address automatically populates this field; however, you can change the address.)

In Figure 5-14 a multicast cloud has already been chosen and the window has refreshed, showing the IP address range for the cloud.

Figure 5-14 Assigning Multicast Cloud to Channel Assignment Window

Step 7 Click Submit.

Step 8 To remove a multicast cloud from a channel, go to the Assigning Multicast Clouds to Channel window. (See Figure 5-13.)

Step 9 Click the Edit icon next to the name of the multicast cloud that you want to remove. The Assign Multicast Cloud to Channel Assignment window appears.

Step 10 Click the Trash icon. You are prompted to confirm the action.

Step 11 Click OK. The channel is removed.

Verifying the Multicast Configuration

Use the following checklist to verify your multicast configuration:

1. Verify that all Content Engines being added to the multicast cloud are online and enabled for multicasting by using the show multicast EXEC command.

2. After multicast connectivity has been confirmed, configure the multicast cloud parameters: sender, advertisement address, transfer address, range, multicast-out bandwidth, multicast medium (satellite or terrestrial), number of carousel passes, and receiver Content Engines.

3. Verify the properties of the multicast cloud by using the show distribution mcast-data-sender EXEC command for the sender Content Engine and show distribution mcast-data-receiver EXEC command for receiver Content Engines.

4. Configure a channel for multicasting and assign a multicast cloud to it.

5. Assign multicast senders and the desired receiver Content Engines from the assigned multicast cloud to the channel.

6. After a multicast channel has been configured on the Content Distribution Manager, use the show statistics distribution mcast-sender EXEC command and the show statistics distribution mcast-receiver EXEC command to show the progress of a data transfer.

Commands Related to Multicasting

Table 5-5 lists and describes CLI commands that are related to multicasting. For complete descriptions of these commands, including usage guidelines and examples, refer to the Cisco ACNS Software Command Reference, Release 5.1 publication.

Table 5-5 Multicast-Related Commands

Command

Syntax

Description

distribution multicast

distribution multicast send-nack-now

Generates a NACK for missing objects and sends them to the multicast receiver.

distribution multicast resend

Resends an individual object (object option) or specifies that the first round of carousel passes be triggered by a NACK only (on-demand-only option).

distribution multicast stop

Sets the number of carousel passes completed to the maximum value so that no more multicast carousels can be triggered.

distribution multicast connectivity-test

Verifies multicast connectivity between a sender and one or more receivers.

multicast

multicast {accept-license-agreement | enable | evaluate | license-key key | sender-delay delay}

Controls enabling and disabling of multicasting, including reading and accepting the license and entering the key.

Note We recommend that you use the Content Distribution Manager GUI to configure multicasting.

multicast fixed-carousel enable

Enables fixed carousel sending, regardless of receiver feedback; NACK triggered carousel passes are disabled. Only applies to the primary sender and is disabled if the Content Engine becomes a backup sender.

multicast priority-weight

Sets the percentage of multicast bandwidth for priority-based scheduling. The remaining bandwidth is given to time-based scheduling of queued jobs.

The default is 50%.

show multicast

show multicast [license-agreement]

Displays the current status of the multicast client. If the license-agreement option is included in the command string, the full text of the multicast license agreement is displayed.

show distribution

show distribution mcast-data-receiver

show distribution mcast-data-sender

Shows the multicast receiver or the sender state. Displays information about the multicast cloud.

show statistics distribution

show statistics distribution mcast-data-receiver

show statistics distribution mcast-data-sender

Displays the content distribution statistics of the multicast data receiver or sender.

clear statistics distribution

clear statistics distribution mcast-data-receiver

clear statistics distribution mcast-data-sender

Clears multicast statistics.