[Serusers] SER Running but .......

[micadeyeye at crg.ee.uct.ac.za]

Hi,
I already have SER running on my PC but I couldn't go further to establish
a communication between two sip phones (softphones on my system).

I tried using EKIGA softphone and LINPHONE in UBUNTU but futile.
Questions:

1. Can I use SER without specifying "LISTEN=XX.XX.XX.XX" because it was
not included in the ser.cfg file which i recently downloaded?

2. Do I need to get NAT transversal inplace before communication can be
established despite the use of 2 softphone on my PC?

3. I did the required modification to ser.cfg in order to use Mediaproxy
but I keep getting "1 error" each time I restart SER.

The modification made was this:
modparam("mediaproxy", "mediaproxy-socket", "/var/run/mediaproxy.sock")

changed to

modparam("mediaproxy", "mediaproxy-select", "/var/run/proxydispatcher.sock")

KINDLY HELP OUT.

MIKE