Date: Mon, 04 Nov 2002 00:24:34 -0800 From: "Paul A. Scott" <pscott@skycoast.us> To: Ertan Kucukoglu <ek@kalyonbilgisayar.com.tr>, <freebsd-questions@freebsd.org> Subject: Re: MSN voice conversation + NATD problem. Message-ID: <B9EB6EC2.EFCC%pscott@skycoast.us> In-Reply-To: <web-7392130@doruk.net.tr>
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> I wanted to setup one machine that can make voice > connections over natd. natd doesn't handle voice protocols. redirecting the ports won't work. > When I try to make voice connection to other machine I just > can not connect. correct. > We tried netmeeting too. It uses same MSN ports. And, under > netmeeting, other end see my ip number as 192.168.0.20. I > do not know why. I'll tell you why. Because every voice protocol I've ever seen gets the local ip address and sticks it in the data stream. (I really wish someone would explain just one good reason for doing this--the ip header should be all that's needed.) Anyway, your local ip address is stuffed in the data stream and gets through unchanged. On the way back, the addess is an rfc1918 intranet address, so it isn't routable, and your connection fails. Now, if natd was smart enough to recognize the protocol you're using, then it could stuff your outside interface ip address in the data stream (as well as the ip header), and replace it with your local ip on the way back in. This is what it does for ftp. BTW, I don't get the rationale behind ftp doing this stupid programmer trick either, but natd has always supported ftp, so whut the hell. A long time ago, I wrote a patch to natd to work with "netphone" or some such cool product. It actually worked and could support any number of pc's behind the firewall. But those were the days of 28kbps dial-up modems and really lousy ISP's. So, performance was never good enough to justify it's continued use. Today might be a different story. Unfortunately, the code is backed up somewhere in a pile of a few hundred CD's. I just don't have the time to locate the code, or the time to retrofit it I did find it. BTW, I never could get NetMeeting to work with natd. The problem was that I couldn't understand the protocol. If I remember correctly, NetMeeting uses the H.323 standard. I seem to recall digging through the standards docs and thinking, "gee could they make this any more complex?" Bottom line is, you won't get natd working with NetMeeting unless you become an expert in the underlying protocol (not likely) or someone who is an expert helps you out. That's not me, sorry. Paul A. Scott mailto:pscott@skycoast.us http://skycoast.us/pscott/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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