User's Manual
RealPresence Collaboration Server (RMX) 1500/2000/4000 Administrator’s Guide
5-36 Polycom, Inc.
match the actual rate of the IP Only HD Video Switching conference running on 
the MGC. In such case, the conference can include IP Only participants. 
— H263_ANNEX_T=YES (default)
This flag enables/disables the use of Annex T with H263. Set it to NO if the 
endpoints connecting to the conference do not support this mode. In such a case, 
you must also change the MGC flag ENABLE_H239_ANNEX_T setting to NO.
— FORCE_1X1_LAYOUT_ON_CASCADED_LINK_CONNECTION=YES 
(default).
Set this flag to NO If the MGC is functioning as a Gateway and participant layouts 
on the other network are not to be forced to 1X1.
3 If the MGC is dialing the Collaboration Server and the cascaded link connects to the 
conference via the Cascade-enabled Entry Queue without being prompted for the 
conference password, set the flag to YES as follows:
— ENABLE_CASCADED_LINK_TO_JOIN_WITHOUT_PASSWORD=YES
4 Click OK.
5 Reset the MCU to apply the changes.
Setting Flags in the MGC
Flag setting is required to ensure the correct MCU behavior for cascading conferences. It is 
performed once per MCU.
To modify the flags:
1 In the MGC Manager, right-click the MCU icon and then click MCU Utils>Edit 
“system.cfg”.
2 In the H264 Section, ensure that the following flags are set to:
— ENABLE_HD_SD_IN_FIXED_MODE=YES
Setting this flag to YES enables H.264 Standard Definition (SD), High Definition 
(HD) and VSX 8000 (Version 8.0) support in Video Switching conferences. 
— H264_VSW_AUTO=NO
Setting this flag to NO disables the highest common mechanism in H.264 and 
enables the selection of H.264 Video Protocol in fixed mode in Dual Stream Video 
Switching cascading conferences.
— ENABLE_H239_ANNEX_T=YES 
This flag should be set to the same value (YES/NO) as the settings of the 
Collaboration Server flag H263_ANNEX_T 
3 Click OK.
4 If you changed the flags, reset the MCU.
If the flag MIX_LINK_ENVIRONMENT is set to YES, the IP_LINK_ENVIRONMENT flag must be set 
to NO.
If the flag MIX_LINK_ENVIRONMENT is set to NO, the IP_LINK_ENVIRONMENT flag must be set 
to YES.
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. 










