ARCHIVE: Creating Cascaded Conferences Across Two Cisco TelePresence MCUs

[Paula Talamo]

Note:  This is an archived technical document expired April 2012.

Creating cascaded conferences across two Cisco TelePresence MCUs

A cascaded conference is a single conference occurring over more than one Cisco TelePresence MCU. These MCUs may be located at different locations. The cascade occurs between a single master MCU and one or more slave MCUs. Endpoints can be connected to either the master or slave MCUs. Each slave communicates with the master over a H.323 connection. These connections use up a port on each slave MCU and one port per slave on the master MCU.

During a cascaded conference the video from the active speaker on a slave MCU is sent to the master MCU. On the master MCU, the video from all slave MCUs and the directly attached endpoints are mixed according to the conference layout. This view is then sent back to each slave MCU, which then forwards this to its endpoints. Each of these endpoints receives a separately encoded copy of the stream based on their capabilities.

You can create a cascaded conference in three ways, using the:

• Web interface of your Cisco TelePresence MCU
• Remote management API
• Cisco TelePresence Conference Director

Cascading a conference using the web interface

Setting up MCU 1

1. On your first MCU (called MCU1 in this article), go to Endpoints.
2. Click Add H.323.
3. Complete the fields as follows:
4. For Name, enter MCU2
5. For Call-out parameters and Call-in match parameters, enter the IP address of MCU2
6. For Default family view, select one participant, full screen

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   Note: This is the view that participants connecting directly to MCU1 will see. This setting is important because it ensures that MCU2 sends only one participant at a time to MCU1 when the cascade is active.    

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7. For Display name override, enter a single space. This precents the MCU from overwriting the participant names along the cascade link, allowing you to see the name of participants on MCU2
8. Click Add endpoint
9. Go to Conference > Add new conference.
10. For Name, enter a name for your conference.
11. For Numeric ID, enter a numerical ID for your conference (in this article, 333).
12. Select the Permanent checkbox.
13. Click Add conference. You are returned to the Conference list.
14. Select the new conference and click the Participants tab.
15. Add the participants who will be connected directly to MCU1 (for more information about this, see the online help).

Setting up MCU 2

The steps below set up a gateway so that the MCUs can communicate directly and then bring MCU1 into the conference. (The gateway only needs to be set up once and will be used every time this conference occurs).

1. On your second MCU (called MCU2 in this article), go to Gateways.
2. Click Add new H.323 gateway.
3. Complete the fields as follows:
4. For Name, type MCU1
5. ForAddress, type the IP address of MCU1
6. If required, limit the bandwidth that will be used to call between the two MCUs
7. For Display name override, enter a single space. This prevents the MCU from overwriting the participant names along the cascade link allowing you to see the names of participants on MCU1
8. Click Add H.323 gateway.
9. Go to Endpoints and click Add H.323.
10. Complete the fields as follows:
11. For Name, enter Cascade to MCU1 conference 333
12. For Call-out address, enter 333
13. For H.323 gateway, enter MCU1
14. For Default family view, select one participant, full screen
15. For Automatic disconnection, select Enabled. This means that the cascade is automatically disconnected at the end of the conference
16. Click Add endpoint.

Setting up the conference

To set up the conference on MCU1:

1. Go to Conferences and click Add new conference.
2. For Name, enter a name for your conference.
3. For Numeric ID, enter the Numeric ID defined about (in this example this is 333).
4. Make sure that the Numeric ID registration checkbox is not selected.
5. Select Permanent.
6. For Invite pre-configured participants, select When at least one other participant is present.
7. Click Pre-configured participants.
8. Select H.323: Cascade to MCU1 conference 333.
9. Select any other pre-configured participants you want to join the conference.
10. Click Return to conference configuration.
11. Click Add conference. You are returned to the Conference list.
12. Select the new conference and click the Participants tab.
13. Add the participants who will be connected directly to this MCU.

Starting the conference

As soon as the conference on MCU1 starts, it calls any pre-configured endpoints including the MCU2 conference 333. This means it calls directly into the conference 333 on the MCU2 cascading the MCUs together. Endpoints connected to conference 333 on both MCUs participate in the same conference.

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Notes:

• Cascading in this way would lose two ports for each cascade, providing a total of 78 ports
• Some functionality is lost between the cascade - such as the ability to choose the layout of participants on MCU2 if you are connected to MCU1
• It is possible to set up the units so they automatically cascade as part of a scheduled conference (one can automatically dial the other and join a conference. The correct layout to send between the units - one large pane - is pre-configured)
• Cisco acquired Codian products do cascading differently from Radvision.

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Cascading a conference using the management API

To cascade a conference across two Cisco TelePresence MCUs using the Management API (rather than the web interface or Cisco TelePresence Director):

1. Add a participant to the 'slave' MCU using participant.add with the extra parameter linkType=cascadeSlaveToMaster (see the Remote Management API Reference Guide).
2. In order to call directly into the conference on the 'master' MCU, when you create the cascade participant using participant.add:
3. for the Address parameter enter the conference id
4. for the gatewayAddress parameter enter the ip address of the master MCU

During the conference the master MCU sends a CP layout to the slave, while the slave sends a 1x1 voice-switched layout back. All participants on the slave MCU view the layout sent from the master, with one of the panes always showing the loudest participant on the slave.

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Cascading a conference using Cisco TelePresence Conference Director

To create a cascaded conference using Cisco TelePresence Conference Director:

1. Select which Cisco TelePresence MCU will be the master MCU.
2. If necessary go to View > Group by MCU.
3. Do one of the following:
4. To create the cascaded conference "from scratch", right-click on the master MCU in the Tree View and select Create conference. (Alternatively, select the master MCU and then go to Conference > Create conference or click the Create conference toolbar icon.)
5. To create the cascaded conference from a template, drag the template from the Conference templates window onto the master MCU in the Tree View. The Create conference dialog opens. Note that if the template had an MCU address completed, then this MCU address is overwritten by that of the MCU that you dropped the template on to. If this is also the address of one of the slave MCUs in the conference template, you will see an error message when you click OK.
6. In the Participants page enter/update the details of any endpoints that will be called by the master MCU in the normal way.
7. Enter/update the details of the conference: be sure to set a numeric ID for the conference on the master MCU in the General page because this is required to allow the slave MCUs to connect to the master MCU.    

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   Note: The start time for a cascading conference is set appropriately on all MCUs involved in the conference so long as you have set the time zone offsets; it does not matter if Cisco TelePresence Director, the master MCU and any salves MCUs are in the same or different time zones. The time you set is your local time and is the adjusted for the time zone offset of the master MCU; the start time on each slave MCU is set to take into account the difference in time zone between the master MCU and that slave MCU.    

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8. To select the view seen by the endpoints on the slave MCUs, open the Layout page, select Enable conference custom layout and Make new participants see this view.
9. Click Set layout and select the view. Click OK.
10. Open the Cascading page.
11. To add a new slave MCU, click Add.
12. The Add cascaded conference dialog opens with the General page open. This dialog has the same pages as the Create conference dialog with the exception of the Repeat page.
13. Enter the name of the conference as you want it to appear on the slave MCU and enter the MCU's IP address.
14. In the General page you can enter a Numeric ID if required, but we recommend that you do not use the Numeric ID entered for the conference on the master MCU.
15. In the Participants page add details of the participants that will be connected to this slave MCU.
16. Add any other information required on the other pages.
17. Click OK. The name of the MCU is displayed in the Cascading page.
18. Repeat from step 7 until all the slave MCUs have been configured.
19. To amend any details of conferences on slave MCUs, repeat from step 7 but highlight an MCU and click Edit in step 8.
20. If a template is required based on this cascading conference, select Add to conference templates.
21. Enter any remaining details for conference on master MCU not entered previously. Click OK.
22. If you entered the IP address of an MCU that you are not already connected to The Connect to MCU dialog is displayed. Enter the username and password of a user with admin rights on that MCU and click OK.

The conference is created. When it is active, the Cascaded Conference icon on the slave MCUs shows that it is a cascaded conference.

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This article applies to the following products:

• Cisco TelePresence MCU 4200 / MSE 8420
• Cisco TelePresence MCU 4500
• Cisco TelePresence MSE 8510 blade

Note:  This is an archived technical document expired April 2012.

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April 13th, 2011

TAA_KB_43

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