From reading through the mailing list I believe there are a number of requirements to address:

1. Combing CardDAV & CalDAV on Baïkal as per:

https://www.inf-it.com/mlmmj/davclients/2015-01/0000032.html

2. Patching Baïkal as per:

3. Cross domain config for Baïkal vhost as per:

As far as I know, I've made all the changes as required. I've tried using globalNetworkCheckSettings in both a cross domain and non cross domain setup. The results are as follows:

Cross domain:

Login screen is presented. I enter the username / password. Nothing happens. Browser console:

Non cross domain:

Login screen is presented. I enter the username / password. The browsers throws an "Authentication required" prompt. No matter what I enter, even if it's a username / password that works with other clients) the prompt just loops. Browser console:

Info: [globalNetworkCheckSettings: 'http://server.xxx.xxx/baikal/html/calcard.php/principals/']: crossDomain set to: 'false'

If anyone can advise as to what I'm doing wrong, it would be very much appreciated. If you need any more info, please let me know. Cheers.