[SR-Users] nat_uac_test mode parameter 16

I just spend a lot of time to fix a trouble with Cisco AS5300 (AS5350) BYE message disapearing. The same not resolved case here: http://lists.iptel.org/pipermail/serusers/2005-July/021698.html The source of trouble was in the nat_uac_test parameter 16: Here is the part of cisco log: Jul 31 12:16:00.726 UKR: CCSIP-SPI-CONTROL: act_idle_connection_created: Connid(1) created to 193.28.184.13:5060, local_port 50058 --Skipped--- Jul 31 12:16:00.738 UKR: Sent: INVITE sip:3039100@193.28.184.13:5060 SIP/2.0 Via: SIP/2.0/UDP 193.28.184.21:5060 From: <sip:2308228@193.28.184.21>;tag=12E601F8-10C7 To: <sip:3039100@193.28.184.13> Via header the same in the all availible IOS-es. As the result openser considerate the Cisco is out of the nat box. The question is: Can someone show me the case when this parameter is necessary, before I'll switch it of on the production server? Thanks in advance. Andrew O. Zhukov.