Webex is missing a SIP feature described in RFC3326 section 3.1
When a forked call is picked up by a device, other devices receive a CANCEL Request with The Sip header "Reason:SIP;text="Call completed elsewhere";cause=200" in the content. UC-One but also Hardphones cancels the session while ringing and don't register the call as being missed. Webex however cancel the session and registers the call as a missed call inspite of the Reason Header.
This affects The Webex app in a Huntgroup, CallCenter, Broadworks Anywhere, Shared Call Appearance, Simultanious ring and other forked call scenario's.
I suggest that Webex does process the Sip Header and when it occurs in a CANCEL request the call is not registered as a missed call.
Code Sample SIP CANCEL Request:
CANCEL sip:firstname.lastname@example.org SIP/2.0
Reason:SIP;text="Call completed elsewhere";cause=200
Thanks and kind regards,