Hi Matthias,


they can split the internet from the internal net. Have you ever tried to get Netmeeting running over a linux gateway running on a 486DX4100 without the need to switch of your firewall. It is completly a mess.
Yes I have ... that what H.323 Gatekeepers are for.

Do you think the ITU has choosen UDP as a transport for the media data
if they wouldn't have had a good reason? TCP has many disadvantages for
for real time data because of the build in error recovery and flow
control. TCP is just not made for real time data.

Sure, i agree with you. That was not my point if you use TCP or UDP. I think also that UDP is the right choice for that stuff. The point is that after a call is made, the oposite client can connect to any port, so it must be open. This is also if you are running a gatekeeper (www.openh323.org).

And UDP/TCP is the point. You need the Gatekeeper for H.323 and the
proxy for SIP not because they don't have external servers (in fact they
can have), but because it's often hard to cross NAT with UDP packets as
there is no connection for which the NAT router can know how do deliver
incoming IP packets.

Yes, that could be true. My point of interest on gatekeepers is the level of DSL-Rourters or smal linux boxes running some IP-Masqurading
stuff.


There are not much techniques available to solve this problem (beside
the Gatekeeper/Proxy on the NAT system). Possibilities include:
- using TCP - problems see above. Sometimes it's implemented that the
  TCP connection is dropped as soon as there should be incoming traffic
- Using any sort of a proxy on the NAT: Gatekeepers, proxies, SOCKS, ...

OK, but what is the situation if both clients are connected via a ISP.
The dont have nothing tu do with NAT etc. What's the situation then.
What is if one has a DSL-Router with a VPN behind (192.168) and the other partner have a direct conection (ISP)?


Thanks,



Carsten

_______________________________________________
jdev mailing list
[EMAIL PROTECTED]
http://mailman.jabber.org/listinfo/jdev

Reply via email to