Polycom RMX 1500 Administrator's Manual page 214

Chapter 3-Cascading Conferences
3-50
— ENABLE_H239_ANNEX_T=YES
This flag should be set to the same value (YES/NO) as the
settings of the RMX flag H263_ANNEX_T
To use MIH Cascade in the MGC, the Conference Numeric ID routing mode must
be used. It is determined when the system.cfg flag in the GREET AND GUIDE/IVR
section is set to QUICK_LOGIN_VIA_ENTRY_QUEUE=NO.
3
Click OK.
4
If you changed the flags, reset the MCU.
Defining the Cascading Entry Queue in the MGC
The Entry Queue definition on the MGC is required if the dialing is done
from the RMX to the MGC.
1
In the MGC Manager, expand the MCU tree.
2
Right-click the Meeting Rooms, Entry Queues and SIP Factories icon and
click New Entry Queue.
3
In the New Entry Queue dialog box, set the Entry Queue parameters
and select the Cascade check box.