プロキシ認証

[1] Proxy-Authentication breaks many applications – IEInternals (2017-08-26 12:17:10 +09:00) https://blogs.msdn.microsoft.com/ieinternals/2012/08/03/proxy-authentication-breaks-many-applications/

[2] Release Notes for Cisco Jabber for Windows 12.7 - Cisco (2019-12-07 10:34:41 +09:00) https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/jabber/12_7/jabw_b_release-notes-12-7.html

Earlier releases do not support proxy authentication. Jabber now supports proxy authentication as outlined in this table:
Product
Supported Authentication Types
Supported Proxy Configuration Methods
Cisco Jabber for Windows
No Auth, Basic, NTLM, Negotiate
Manual, PAC
Cisco Jabber for Mac
No Auth, Basic, NTLM
Manual, PAC
Cisco Jabber Softphone for VDI
No Auth, Basic, NTLM, Negotiate
Manual, PAC