I am trying to establish a data call from one phone to the other using the methods outlined in the following site

Now, my first data call from one phone to the other goes through fine. Then I hangup the call using HangUp function of RCall and that also goes through fine. However when I try to make a subsequent data call that just does not go through. Any insights into as to what I might be missing out.

After I hang up a call I close the RCall resource, but leave the RTelServer, RLine and RPhone resources open (they are opened in the constructor and I am of the opinion that they do not need to be closed after every call, but only when the application is closed),

Any insights would be most helpful