Hi Mike,
No they do not need to match
I found this:
Authenticate with Cisco WebEx Meetings Server
Cisco Jabber supports the following methods of authentication with Cisco WebEx Meetings Server:
- Users manually enter credentials in the client
Each user can enter their credentials in the Options window to authenticate directly with Cisco WebEx Meetings Server.
- You set a credentials source on Cisco Unified Presence
If the users' credentials for Cisco WebEx Meetings Server match their credentials for Cisco Unified Presence or Cisco Unity Connection, you can set a credentials source. The client then automatically authenticates to Cisco WebEx Meetings Server with the users' credential source.
- You configure single sign-on (SSO) with Cisco WebEx Meetings Server
If you configure SSO with Cisco WebEx Meetings Server, Cisco Jabber can seamlessly integrate with the SSO environment. In this case, you do not need to specify credentials in order for users to authenticate with Cisco WebEx Meetings Server.
On this guide:
http://www.cisco.com/c/en/us/td/docs/voice_ip_comm/jabber/Windows/9_7/JABW_BK_C4D2F1D0_00_cisco-jabber-for-windows-97/JABW_BK_C4D2F1D0_00_cisco-jabber-for-windows-97_chapter_01100.html#CJAB_TK_C8089CD7_00
On CUCM 10.5 login to the admin page and go to User Configuration >> User Settings >> Service Profile >> <Your_Service_Profile> and look for "Conferencing Profile" you will see "Credentials source for web conference service" where you can choose Not Set, IM & Presence or Voice mail.
Hope this helps.
Oscar Chavarria
