Jiri Kuthan writes:
other way of dealing with NATs is use of
nathelper -- nathelper can
send keep-alive messages to natted clients.
jiri,
this has nothing to do with nated hosts, my gprs provider gives me a
globally unique ip address. because they charge per mbyte and want to
"protect" me, they don't allow anyone from outside to establish tcp
connection to me or send any unsolicited udp packets to me. therefore,
the only way i can get sip presence and instant message applications to
work, is that ser uses the same tcp connection that i have established
for all requests sent to me.