I am trying to find out if the 2 FXS ports on the SPA9000 are supporting the SIP-B.
While the SPA ip-phones have an explicit option that enables/disables this feature,
the FXS lines are missing it completely, will this mean that the FXS ports do not
use the SIP-B extensions?
Unfortunately I cannot find any confirmation on the SPA9000 admin guide.
I am trying to find this out because I noticed a strange behavior of the FXS ports when
added to an hunt-group.