Channels partition and isolate peers and ledger data to provide private and confidential transactions on the blockchain network.

Each peer that joins a channel has its own identity that authenticates it to the channel peers and services. Although peers can belong to multiple channels, the information on transactions, ledger state, and channel membership is restricted to peers within each channel. 

You can use the Oracle Blockchain Platform console or the Hyperledger Fabric SDK to create channels on your blockchain network. See View Channels.

Members in your network use channels to privately communicate blockchain transactions information.

1. Go to the console and select the Channels tab.
   The Channels tab is displayed and the channel table contains a list of all of the channels on your network.
2. In the channel table, click the channel name you want information about. Note that if all peers joined to the channel are stopped, then the channel is listed but its information isn't available to view.
   The Channel Information page is displayed.
3. Click through the Channel Information page's panes to find information about the channel.

   Section	What can I do in this pane?
   Ledger	Get information about the channel’s ledger activity such as block number and the number of user transactions in the block. Click a block number to drill into information about its transactions. You can use the filter field to specify the summary information that you want to see (for example, information from the last day or last month), or use the custom option to enter start and end times. See View a Channel’s Ledger Activity.
   Deployed Chaincodes	View the list of chaincodes that have been deployed on the channel.
   Orderers	View a list of the orderers currently active, and allows you to add a new OSN to join the channel.
   Peers	View the list of peers that are joined to the channel. Use this section to set anchor peers for the channel.
   Organizations	View the list of network members whose peers are using the channel to communicate.
   Channel Policies	View the list of the standard policies and any policies that you created for the channel. Use this section to add, modify, and delete policies.
   ACLs	View the access control lists (ACLs) and the policies used to manage which organizations and roles can access the channel's resources.

You can add channels to the network and specify which members can use the channel, and which peers can join the channel. You can’t delete channels.

1. Go to the console and select the Channels tab.
2. In the Channels tab, click Create a New Channel.
3. In the Channel Name field, enter a unique name for the channel. The channel's name can be up to 128 characters long.
4. In the Organizations section, select any additional members that you want to communicate on the channel.
   If you’re working in a participant instance, you need to add the founder to your instance before the founder’s MSP ID displays in the Organization section. To add the founder organization, go to the Network tab and click the Add Organization button to upload the founder’s certificates.
5. In the MSP ID ACL section, specify the organizations that have access to the channel and permissions for each selected organization. Note that you can add more organizations to or delete them from the channel later, as needed.
   Your organization’s permissions are set to write (ReaderWriter) and you can't modify this setting. By default, other member’s permissions are set to write (ReaderWriter), but you can change them to read (ReaderOnly) if you don’t want the members to invoke chaincodes and to only read channel information and blocks on the channel.
6. (Optional) In the Peers to Join Channel field, select one or more peers. Note the following information:
   • If your network contains participants, the participants’ peers don’t display in this list. Participants must use their consoles to join peers to the channel. A participant can’t join its peers to the channel unless its organization was added to the channel’s MSP ID ACL section.
   • If you want to create the channel only, then don’t select any peers. You can add peers to the channel later.
7. Click Submit.
   The channel table displays the new channel.

Use the ledger to find summary information and runtime statistics for transactions on a specific channel.

1. Go to the console and select the Channels tab.
2. In the channel table, click the channel name that you want transaction information about. In the Channel Information page, confirm that the Ledger pane is selected.
3. Use the Ledger Summary area to find basic information about the channel’s activity, such as the total number of blocks in the ledger’s chain and the total number of user transactions on the channel.
4. To see blockchain activity that occurred at a specific time such as the last day or week, use the filter drop-down list to select the time range that you want. To locate and drill down into a specific set of transactions, select Custom and enter search criteria in the Start Time and End Time fields, or click the calendar icon and pick the dates that you want. Click Apply.
   If you select a specific time period (for example, Last day) and then select it again to re-run the query, the query doesn’t run again. To get the latest information, click the Refresh button.
   The following transaction types can be displayed for a block:

   • genesis — The transaction that runs the configuration block to initialize the channel.
   • data (sys) — The transaction that starts the chaincode’s container to make the chaincode available for use.
   • data — A chaincode transaction called for execution on the channel.
5. To find more information about a specific transaction, locate the transaction in the query ledger table and click it. The transactions table displays the transaction’s details.

   For any given block, the transactions in the table are listed in the order of the transaction number, which is assigned by the ordering service when the block is created. Because of this, the transactions listed in the table might have time stamps (which are from the peer's endorsement of the chaincode) that are before or after other transactions in the same block. The time range of transactions in a single block is governed by ordering service settings including the batch timeout parameter (the time that the ordering service waits for additional transactions after an initial transaction before cutting a block).

   Transaction Detail	Description
   TxID	The unique alphanumeric ID assigned to the transaction. The TxID is constructed as a hash of a nonce concatenated with the signing identity's serialized bytes.
   Time	The transaction’s time stamp (date and time that the transaction occurred).
   Chaincode	The name of the chaincode that ran the transaction. This field can show the name of a chaincode that you wrote, installed, and deployed, but can also show a system chaincode. System chaincode options are: _lifecycle — For lifecycle requests, such as install, deploy, and upgrade. QSCC — For querying. This chaincode includes APIs for ledger query.
   Status	Status that indicates whether the transaction succeeded or failed.

6. Click the triangle icon next to the TxID to view in-depth information about the transaction, such as function name, arguments, validation results, response status, the initiator, and the endorser.
   If a transaction failed, you can use the TxID to search the error logs on the peer node or orderer nodes for more information.

You can view the list of the organizations that have access to the channel. If you created the channel, then you can change an organization’s permissions on the channel, and you can add organizations to or remove them from the channel

1. Go to the console and select the Channels tab.
   The Channels tab is displayed and the channel table contains a list of all of the channels in your network.
2. In the channels table, locate the channel that you want information about, click the channels More Actions button, and click Edit Channel Organizations.
   The Edit Organizations page is displayed.
3. In the MSP ID ACL section, you can do the following:

   • Modify an organization’s permissions. The organization that created the channel is set to write (ReaderWriter). You can't change this setting.

   • If you’re the network founder, then clear an organization’s checkbox to delete it from the channel. If you’re a network participant, then use the Delete button to delete an organization from the channel. If you delete an organization from a channel, then the organization and its peers can no longer query, invoke, and instantiate a chaincode on the channel. And the removed organization’s peers can’t join the channel.

   • Click an organization’s checkbox to add the organization to the channel and set its permissions. By default, each member’s permissions is set to write (ReaderWriter), but you can change it to read (ReaderOnly) if you don’t want the member to invoke chaincodes and to only read channel information and blocks on the channel.

4. Click Submit to save the changes.

You can add a peer node to a channel so that the node can use it to exchange private transaction information with other peer nodes on the channel.

1. Go to the console and select the Nodes tab.
2. In the Nodes tab, click the peer node that you want to add to a channel.
3. In the Node Information page, click the Channels pane to view the list of channels the peer is already using.
4. Click Join New Channels.
   The Join New Channels dialog is displayed.
5. Click the Channel Name field and from the list select the name of the channel to join. Click the field again to select another channel. Click Join.

Each member using a channel must designate at least one anchor peer. Anchor peers are primary network contact points, and are used to discover and communicate with other network peers on the channel.

1. Go to the console and select the Channels tab.
   The Channels tab is displayed and the channel table contains a list of all of the channels on your network.
2. In the channels table, click the channel name you want to add anchor peers to.
   The Channel Information page is displayed.
3. In the Channel Information page, click the Peers pane.
4. Locate the peer or peers that you want to designate as anchor peers and click their Anchor Peer checkboxes to select them.
5. Click the Apply button.

You can change or remove a channel's anchor peers. Anchor peers are primary network contact points, and are used to discover and communicate with other network peers on the channel.

1. Go to the console and select the Channels tab.
   The Channels tab is displayed and the channel table contains a list of all of the channels on your network.
2. In the channels table, click the channel name you want to remove anchor peers from.
   The Channel Information page is displayed.
3. In the Channel Information page, click the Peers pane.
4. Locate the peer or peers that you want to remove as anchor peers and clear their Anchor Peer checkboxes. Alternatively, to add another peer as an anchor peer, click its Anchor Peer checkbox to select it.
5. Click the Apply button.

You can view information about the chaincodes that are deployed on the different channels in your network.

1. Go to the console and select the Channels tab.
2. In the channels table, click the channel name with the chaincode that you want to view information for.
3. In the Channel Information page, confirm that the Deployed Chaincodes pane is selected
4. In the chaincode table, you can:
   • Click the chaincode package ID to go to the Chaincodes tab to learn more information about it. For example, the peers that the chaincode is installed on and the channels that the chaincode is deployed on.
   • In a chaincode’s More Actions menu, click View Chaincode Definition to find details about the chaincode’s definition, including the endorsement policy.
5. (Optional) If you see a channel listing without a chaincode, then you can go to the Chaincodes tab and deploy a chaincode to the channel. See Deploy a Chaincode.

This topic contains information about a channel's policies and access control lists (ACLs). It provides an overview of what policies are, policy types, and how to modify them, as well as how to use ACLs to manage which organizations and roles can access a channel's resources.

The orderer admin organization can add or remove orderers from a channel.

You can assign the administration of OSNs in a channel to any organization. Normally either the founder or the channel creator would be assigned.

1. In the founder console, open the Channels tab.
2. Select the channel for which you want to set the orderer administrator organization, and from the Action menu select Manage OSNs Admin.
3. Select from the list of available organizations, and click Submit.

You can update the ordering service settings for a particular channel.

1. Go to the founder’s console and select the Channels tab.
2. Locate the channel, click the More Actions menu, and select Update Ordering Service Settings.
   The Ordering Service Settings dialog is displayed.
3. Update the settings as needed.

   Field	Description
   Batch Timout (ms)	Specify the amount of time in milliseconds that the system should wait before creating a batch. Enter a number between 1 and 3600000.
   Max Message Count	Specify the maximum number of message to include in a batch. Enter a number between 1 and 4294967295.
   Absolute Message Bytes	Specify the maximum number of bytes allowed for the serialized messages in a batch. This number must be larger than the value you enter in the Preferred Message Bytes field.
   Preferred Message Bytes	Specify the preferred number of bytes allowed for the serialized messages in a batch. A message larger than this size results in a larger batch, but the batch size will be equal to or less than the number of bytes you specified in the Absolute Message Bytes field. Oracle recommends that you set this value to 1 MB or less. The value that you enter in this field must be smaller than the value you enter in the Absolute Message Bytes field.
   Snapshot Interval Size	Defines number of MB per which a snapshot is taken.

4. Click Update.
   The updated settings are saved.