I'm experiencing the problem below, when authenticate a SIP phone(Third SIP Phone).
If the user use alphanumeric (or alphabet only) for example: user1,
then the user cannot the log on the CUCM
But if we use the numeric as user login, for example 1200, then it is working.
How to resolve this issue so that Active directory users can use their current login & password.
It would be best if you can post your question under CUCM section. You would get a faster response,