Do you know what is causing the echo? Is it acoustic echo? Do the endpoint devices have any echo cancelation abilities?
-MC

2011/4/13 vivid333 <vivid333@163.com>
Hi:
          1. can any one know the usage of uuid_preprocess?
          2. according to the FreeSwitch code, this command would add a bug to the uuid session, initialize echo parameters, and in functions switch_core_session_read_frame/switch_core_session_write_frame do echo handle. but  the echo still exist. do any one help me ? thanks..

      Echo Scenes:
      Telephone 1000, 1001 registered the FreeSwitch, 1000 call 1001, 1001 answered( two of them are handfree, producing scary sound);

Try Solution:
Launch the command-line ulility:
#> fs_cli
#>: show channels
uuid1, uuid2

#>:uuid_preprocess uuid1 recho_cancel=true;
#>:uuid_preprocess uuid2 recho_cancel=true;

but the echo still exist. can any one help me, thanks!