Hi Kieron;
Not sure if the delay is just to dial out or to get the PSTN ringing tone
If the delay is just to dial out, two options:
(1) Manual: Press "#" and call will go inmediately.
(2) Modify the dial plan.
The PSTN ringing delay is approximate 3-5 seconds always as the interaction is between IP Phone -> SIP Proxy at SPA9000 -> SIP GW at SPA400 -> analog port SPA9000 -> PSTN. This delay cannot be eliminated or reduced, it is normal behavior.
Hope this helps
Alberto