> >Subject: Re: [sipX-dev] Questions re: NAT traversal configuration > >On Fri, Jun 6, 2008 at 12:30 PM, Robert Joly <[EMAIL PROTECTED]> wrote: >>> 1) The help text on the new NAT traversal page instructs >>> the admin to open ports on the firewall used by the Media >>> Relay. Where are these ports configured and where can I see >>> what the currently configured range is? >> >> I will let Ranga field that one. > >In the sipxbridge settings go to advanced settings. You will see >Strart RTP Port and End RTP Port.THat is the port range that is being >managed.
This seems to require then that an instance of sipXbridge is configured as an SBC, which contradicts Robert's earlier statement from below. I assume that without an instance of sipXbridge configured, Symmitron would use its default RTP port range. The problem remains that the admin is told to open these ports on the firewall without knowing where to find the actual port numbers used. This needs to be addressed. > > >> >>> 2) As far as I understand the media relay used by NAT traversal is >>> shared with sipXbridge. >> >> Correct. BTW, the Media Relay function is called the Symmitron (tm) :) >> >>> Is it a requirement for the the NAT traversal >>> feature to work that an instance of sipXbridge is configured on the >>> SBC page? >> >> No, the sipXbridge which includes the Media Relay function (the >> Symmitron) is started automatically at start-up even when it is not >> configured as an SBC. This is analogous to the call park server being >> launched even when no park orbits are defined. >> >>> If so, sipXconfig should not only tell the user but also verify >>> the availability of a media relay before the admin can enable NAT >> traversal. >>> >>> 3) Max concurrent relays: If it is correct that the media relay is >>> shared with sipXbridge then max concurrent relays would limit the >>> total number of remote worker sessions, but not the max number of >>> relays used for SIP trunking. Correct? >> >> Right. The Symmitron offers a certain quantity of relays of out which >> 'Max concurrent relays' are set aside for the NAT traversal feature. >> Media relays are used every time a NAT separates media endpoints or when >> 3PCC calls are detected. This means that the following conditions will >> use up one media relay: >> - a call to/from Remote Workers >> - When sipXecs is itself located behind a NAT along with some local >> phones then calls between said local phones and other endpoints on the >> public side of the NAT will use up a media relay. >> - Music-on-hold due to 3PCC nature of the call Are you saying that all calls that are put on hold now go through the media relay? If so, why is that? What does this mean: "3PCC nature of the call"? >> - Most calls to devices whose locations are unknown. These are >> typically registration-less devices such as gateways. This does NOT apply to all the PSTN gateways that sit on the same network, correct? >> >> Now, each media relay used by the NAT traversal feature requires 4 ports >> (2 for relaying RTP and 2 for relaying RTCP). This means that the >> theoretical maximum number of relays that the Symmitron can offer is ( > 'Symmitron UDP port range Upper bound' - 'Symmitron UDP port range Lower >> bound' ) / 4. How does NAT traversal relate to Internet Calling? Does Internet Calling have to be enabled in order for NAT traversal to work? On the NAT traversal screen we refer to domain and IP address range configurations that are done on the Internet Calling page. What if the admin has not set that up? --martin >> > _______________________________________________ sipx-dev mailing list [email protected] List Archive: http://list.sipfoundry.org/archive/sipx-dev Unsubscribe: http://list.sipfoundry.org/mailman/listinfo/sipx-dev
