It is not a matter of priorities. It depends on how you get your mediaproxy configured. You need to be aware that nated clients should use the media proxy, because of the nat problem. But, if your client can find ( using stun for example ) his public ip/port, then, from mediaproxy point of view, this client is not nated, and so, it needs not treatment ( no fixing from part of media proxy ). You can always do this: Get every traffic proxied along mediaproxy. But, if clients can talk to each other being able to bypass mediaproxy, why should you proxy your communications ??? Hope to be clear Regards, Lucas -- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.308 / Virus Database: 266.9.4 - Release Date: 06/04/2005

The only circumstances that I know where STUN does not help is when the UA is located behind a symmetric nat. In the othre 3 cases of nat, it should help you just fine. Or if the clients do not implement a good stun-client or the stun server does not implement the protocol correctly. But, let say that every body follows the standars ( JA!, ask cisco ) ... you should not have problems at all. Regards, Lucas -- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.308 / Virus Database: 266.9.4 - Release Date: 06/04/2005

Well, that's true, but you can test to see if the public IP of caller and callee is the same. Of course, you cannot be completely sure whether there are a couple of other NATs behind the public one, but just in case, you should proxy the call to avoid the hairpinning problem. Which of course doesn't help much, because you need to rely on the user client's STUN implementation. g-) Alex Mack wrote: > Lucas Aimaretto schrieb: > >>>>>>>>>> Make sure you are not behind a Symmetric NAT. If >>>>>>>>>> >>>>>>>>>> >>> so, you're >>> >>> >>>>>>>>>> dead. STUN does not work with Symmetric NAT. >>>>>>>>>> >>>>>>>>>> >>>>>>>>> If a UA is behind Symmetric NAT, and >>>>>>>>> UA use STUN, and >>>>>>>>> SER have [RTP/Media]Proxy to handle Symmetric NAT, this UA >>>>>>>>> should be fine, right? >>>>>>>>> >>>>>>>>> >>>>>>>> Yes, but, if UA is behind symmetric NAT, I would not >>>>>>>> >>>>>>>> >>> configure >>> >>> >>>>>>>> STUN to it. I'd just led mediaproxy solve the problem. >>>>>>>> >>>>>>>> >>>>>>> But if you have 100 clients, >>>>>>> it would be hard to put all clients in one group. >>>>>>> >>>>>>> >>>>>>> Good point ! >>>>>> >>>>>>> Yes, it is true. If stun can not solve the nat problem, >>>>>> media proxy >>>>>>> should fix it with no trouble at all. >>>>>> >>>>>> >>>>>> >>>>> If there is no symmetric NAT and I have installed STUN and >>>>> Mediaproxy on my server. Which one will have higher priority >>>>> to handle this call session? Is it always STUN? Of course if >>>>> I don't need to pass the call to PSTN gateway. Just IP-phone >>>>> to IP-phone. Can you set the priority in ser.cfg? and how? >>>>> >>>>> >>>> It is not a matter of priorities. It depends on how you get your >>>> mediaproxy configured. You need to be aware that nated clients >>>> should use the media proxy, because of the nat problem. >>> But, if your >>>> client can find ( using stun for example ) his public >>> ip/port, then, >>>> from mediaproxy point of view, this client is not nated, >>> and so, it >>>> needs not treatment ( no fixing from part of media proxy ). >>> >>>> You can always do this: Get every traffic proxied along >>> mediaproxy. >>>> But, if clients can talk to each other being able to bypass >>>> mediaproxy, why should you proxy your communications ??? >>> >>>> Hope to be clear >>> >>>> Regards, >>> >>>> Lucas >>> >>> >>> >>> Thank you, it makes sence. >>> It would be the best solution I'd say, but it reminds me >>> JavaRocks statement that STUN makes problems in some >>> circumstances.. Just wondering what problems? Maybe some UA's >>> not supporting STUN? >>> >>> >> >> The only circumstances that I know where STUN does not help is when >> the UA is located behind a symmetric nat. In the othre 3 cases of >> nat, it should help you just fine. Or if the clients do not >> implement a good stun-client or the stun server does not implement >> the protocol correctly. But, let say that every body follows the >> standars ( JA!, ask cisco ) ... you should not have problems at all. >> >> Regards, >> >> Lucas >> >> >> > > Hi everyone! > > > Alex Mack > > _______________________________________________ > Serusers mailing list > serusers(a)lists.iptel.org > http://lists.iptel.org/mailman/listinfo/serusers

Right. There is one we like to call the crap-nat. This nat changes the source UDP port every few seconds. So once the media flow is established it only works for 2-3 seconds until the nat switches to another source port. Needles to say there is absolutely no way to make VoIP work unders these conditions. We encounter one of these every few weeks, and the only solution is to have the customer change the NAT device he is using. (these are usually ADSL modems with inbuilt router) -- Andres Network Admin http://www.telesip.net

Pedro, We have already created a link category called "SER-tested SIP clients" at ONsip.org: http://www.onsip.org/modules/mylinks/viewcat.php?cid=15 I don't know if this is what you and others would like to see, but each of the links to client scan be voted on and people can add comments with their experiences. This way the list of clients can be ever expanding and people can easily add their own opinions and we avoid a static list. I see a problem with the lack of structure, so if you have an idea for how to do it in a better way, but still keep the dynamic aspects, I'm listening :-) g-) Jan Pedro Tumusok wrote:

Ladislav Andel wrote: This depends on the client. If the client uses STUN and can traverse the NAT, then ser will not detect a NATed client and should not enforce rtpproxy/nathhelper. regards, klaus