Do you run the latest software on the mcu 4.2(1.50)?
You can define a pre defined "endpoint" there you can select the codec negotiation (if this is what you are aiming for).
Besides that you might want to select a fullscreen switching layout.
Either you should be able to dial out or you would have to see that the dial in matches the pre defined endpoint

Online help info:
"Content negotiation
| This field allows the MCU to be configured so that content can be exchanged with third party MCUs in multi-level cascaded conferences over H.323. Choose from: - As master: The MCU only acts as master in H.239 token negotiation.
- As slave: The MCU acts as the slave in H.239 token negotiation and can send content to a master unit if it accepts the token request.
- As mimic slave: The MCU acts as a mimic slave in H.239 token negotiation and will try to send content to all other endpoints/units even if this unit (i.e. the MCU configured as a mimic slave) rejects the token request.
| |
When exchanging content with an endpoint in a H.323 call, the MCU acts as a master unit and the endpoint as a slave unit for the purpose of H.239 token negotiation. However, in order for the MCU to exchange content with a cascaded third party MCU the MCU must appear to the third party MCU to be a slave unit. The MCU can be configured as a true slave, in which case content will only be sent if the third party MCU master accepts the token request, or as a mimic slave where content is sent to all other connected endpoints even if the third party MCU rejects the token request."