Richard writes:
Can you please elaborate the missing features?
the most important thing is that asterisk doesn't support remote-party-id that is a must for call forwarding and calling number privacy.
a good pstn gw also allows controlling what to do with 3xx replies and refers. it is also desirable to be able to select which interface is used for signaling and which for media. some of these may be possible in asterisk, but i'm not sure.
one advantage of asterisk over cisco is that * has support for free low bit rate codecs ilbc and speex.
If we want to avoid buying the expensive cisco gw, what's the cheap PRI(T1) supported in sems?
jan already answered that sems currently supports. nothing would prevent adding into sems also support for digium te405p/te410p, which i consider a good thing to do.
-- juha