the cx600 show the cannot download certificate because domain is not accessible.

It is on remote site, MPLS the domain is accessible. Using USB to login. Lync Client can Login.

Check the dhcp options ok.

Thanks.

• Edited by Jo Tse 20 hours 2 minutes ago change

A really good troubleshooting step is at the following blog.

http://blog.schertz.name/2012/03/troubleshooting-lync-phone-edition-issues/

Can you list the steps that you have already performed?  Can the device log in over the edge?  Note the certificate information in the blog.

this cx600 firmware still 4372 January 2013. It can't sign-in so failed to upgrade latest firmware.

I using 4455 firmware is able to login. 

Why cx600 using still 4372 with new ship phone...

They using SBA server and user can't sign-in and upgrade firmware. Others latest firmware old cx600 phone are able to login but new come with 4372 firmware can't/

• Edited by Jo Tse 18 hours 47 minutes ago change

yes.  that firmware version caused a lot of problems.    It's going to be a hassle to update those phones.  Sorry for your troubles.  I am glad that you were able to narrow it down.  I'll think about the best way to either roll back or roll forward ...  i'm not sure.

Thanks. if i can't sign-in i can't upgrade the firmware.  i found many people face this problems....with 4372...

I do agree.  Assuming that your external web services are published correctly, LPE will update over the edge.   If you have this option, and it's not too much of a burden, could you try that and see if it's a workaround?

Also, since this is an update related issue - you can call Microsoft for support on it.  

Hi,

From your description above, it is the issue about the old firmware. You may need to update it to the latest firmware by connection the computer with USB.

Best Regards,
Eason Huang