On your cucm, after installing devicepack , did it gave you an option to choose device type as SX 20 while adding the device?  doesnt looks like that dev pack has sx 20 support. So CUCM sends a 404 for registration method.   -------------------------...

Hi,If you can attach xstatus and xconfig. that would be great.I would like to check the temperature and Fan status of the codec //VD

Hi, Why not ?  It is possible. Check where RMX 500 is placed. ie in Lan, DMZ or public internet.If RMX is on lan>  just dial the dialable pattern from SX 10 which RMX understands ie conf code, uri, ip etc to join a meeting.If RMX is on public, config...

Hi, http://www.cisco.com/c/dam/en/us/td/docs/voice_ip_comm/expressway/config_guide/X8-5/Mobile-Remote-Access-via-Expressway-Deployment-Guide-X8-5.pdf check >Page 10 If you have something specific. Please Ask !  //VD