Thanks Stewart and Michal. I have one more question. If there is a gateway with a private IP being NATed behind a firewall that is H.323 aware. After the GW registers with the GK and a caller tries to reach the GW with the private IP how does the set up message make it to the private IP address through the firewall ? If I get this I think it will all make sense. Thanks again. James Lertora Technical Support Patton Electronics mailto:support@xxxxxxxxxx New! Enhanced Warranty and Advanced Replacements are now available for RAS products. Join the Patton users group and learn how others are using the Patton RAS. See www.patton.com/support http://www/patton.com/support for more information. Software/Drivers --> http://upgrades.patton.com > -----Original Message----- > From: openh323gk-users-admin@xxxxxxxxxxxxxxxxxxxxx > [mailto:openh323gk-users-admin@xxxxxxxxxxxxxxxxxxxxx] On > Behalf Of Stewart Nelson > Sent: Wednesday, July 07, 2004 12:32 AM > To: openh323gk-users@xxxxxxxxxxxxxxxxxxxxx > Subject: Re: Question about NATed endpoints > > > Hi Per, > > This is a tough problem. There are indeed situations when > you are stuck behind a NAT over which you have no > administrative control, e.g. in a hotel, or at a vendor or > customer site. > > Although there is generally no signaling problem on outgoing > calls, especially if you use fast start and/or H.245 > tunneling, a NAT that is unaware of H.323 has a potential > problem with the incoming audio: > > 1) The NAT doesn't know what host to send it to, until it > sees some outgoing audio from that host. > 2) Most calling phones / gateways don't send audio until > CONNECT is received. > 3) If the destination is the PSTN via a commercial ITSP, > you won't get CONNECT until the call is answered. > > This means that you will not be able to hear announcements > such as "the number has been changed ..." or "the party you > are calling is out of range". Depending on the carrier, you > may not hear audible ringing or busy signals, either. > > There is usually no trouble if the destination is an IP > phone, an ATA, or a gateway with analog POTS lines. > > It is often necessary to set ProxyForNAT for reliable > operation without DMZ. Unfortunately, that generally > carries a penalty in voice quality and/or delay. > > --Stewart > > ----- Original Message ----- > From: "Per Kreipke" <per@xxxxxxxxx> > To: <openh323gk-users@xxxxxxxxxxxxxxxxxxxxx> > Sent: Tuesday, July 06, 2004 3:17 PM > Subject: RE: Question about NATed endpoints > > > > Stewart, > > > > Thanks, very informative. > > > > I'm curious, if only making outbound calls, is the > situation the same? > > E.g. is it necessary to put the gateway in the DMZ/open ports? > > > > Thanks, > > Per > > > > ------------------------------------------------------- > This SF.Net email sponsored by Black Hat Briefings & > Training. Attend Black Hat Briefings & Training, Las Vegas > July 24-29 - > digital self defense, top technical experts, no vendor pitches, > unmatched networking opportunities. Visit www.blackhat.com > > _______________________________________________________ > > List: Openh323gk-users@xxxxxxxxxxxxxxxxxxxxx > Archive: http://sourceforge.net/mailarchive/forum.php?forum_id=8549 > Homepage: http://www.gnugk.org/ > ------------------------------------------------------- This SF.Net email sponsored by Black Hat Briefings & Training. Attend Black Hat Briefings & Training, Las Vegas July 24-29 - digital self defense, top technical experts, no vendor pitches, unmatched networking opportunities. Visit www.blackhat.com _______________________________________________________ List: Openh323gk-users@xxxxxxxxxxxxxxxxxxxxx Archive: http://sourceforge.net/mailarchive/forum.php?forum_id=8549 Homepage: http://www.gnugk.org/
