[Users] a router error

[messa at innsof.com]

Hi all

   I use d-link 704P router. When i want to make a call, signalisation is
good, but, when the client is hang up, i have voice to the client which
is connect in the D-link LAN and the other client has no voice. My
server has a
public IP.
  When i'm find the log of the router, i see these messages:
unallowed access from 192.168.0.53:to 66.249.93.104:protocol=6 rule=3(by
firewall)

192.168.0.53, is the adress of the client behind the d-link lan, the
client which has voice and cannot transmit it!

   what means theses messages?
how can i solve the router problem to make my calls?

please help

 best regards!
                                Serge