Hello msamy_k,
Two Things:
- UC Software 4.1.7 is no longer a supported software. Please install either UC Software 5.5.0 or UC Software 5.4.4 and test again.
- The community's VoIP FAQ contains this post here:
Oct 7, 2011 Question: Phone unable to Dial a number when Off Hook or on 2nd Call in a Conference or Digitmap issues
Resolution: Please check => here <=
I suggest to check you digitmap and the FAQ to troubleshoot that comes with it.
Please ensure to provide some feedback if this reply has helped you so other users can profit from your experience.
Best Regards
Steffen Baier
Polycom Global Services