[Serusers] nat, symmetric /asymmetric UA....clarification needed

[Vitaly Nikolaev]

You need to send me INVITES from both cases, before and after SER, could it
be the case that when u send call to asterisk u did not do force rtp proxy ?

About detecting, STUN is doing it, some clients (Innomedia) put this info in
sip header.. like nat=6...  or you can understand for urself difference
between different nats and hen u will able to find out type just by looking
at initial REGISTER from customer :) 

-----Original Message-----
From: Iqbal [mailto:iqbal at gigo.co.uk] 
Sent: Saturday, February 26, 2005 1:01 PM
To: vitaly at voipsonic.com; serusers at lists.iptel.org
Subject: RE: [Serusers] nat, symmetric /asymmetric UA....clarification
needed


tks...

2. I mean in when using mediaproxy, there are two files to where u add
asymmetric clients.

Xlite is symmetirc media which is good, which is why it works from behind
a kcorp wireless router with a private IP, however the other xlite,
which is behind a diff router (will hv to check name), just dont work
when going to asterisk for voicemail, but it does everything else like
calling pstn, other xlite behind different NAT's etc...which just dont
make sense, I guess however the device is NATing it is doing it
correctly else i would not be able to call pstn or other sip devices,
its just when it diverts to voicemail, something goes haywire.

STUN I have removed I agree its not a good solution, I am trying to
ensure users dont have to add much more than a username/pass and proxy
address...that usually confuses them enough :-)

Any ideas as to howto detect what type of NATing the customers device
maybe doing, and what type of signallling the UA id doing remotely, that
way it would be easier to offer solutions for both.

Iqbal



On 1/2/2002, "Vitaly Nikolaev" <vitaly at voipsonic.com> wrote:

>
>There could be clients that can use STUN to get their IP/port and NAT
router
>that can try to fix SIP packets. In my opinion both ways are still not good
>for cutomers because of many mistakes. Please make sure that you remove all
>kinf of STUN, ip autodetect from Xlite.
>
>
>In REGISTER that u receiving from UA you should see private IP in Contact
if
>UA behind the NAT, but in location table SER should save right IP (public)
>and right port (could be same or could be different depending on NAT type)
>
>In INVITE same private contact and in SDP media address private.
>
>IF NOT - SOMETHING TRIYNG TO FIX NAT TRAVERSAL instead of media/rtp proxy..
>which is in most cases bad and need to be fixed
>
>
>Make sure that if you have more then one sip UA behind the same nat you
>configure different signaling and media source ports (it may be only true
>for symmetric NAT but it always good to do :)
>
>
>1. - yes
>2. do not know what do you mean. Don't you mix symmetric media and
symmetric
>NAT ? first is good thing when device use same port for sending/receiving
>media and second is BAD, means that .. I am not sure btw.. that NAT will
use
>same source port for your packets regardless.. please correct me
>
>3. Xlite does symmetric signaling/media
>
>4. what file ? :) I think it something mediaproxy related.. I use rtpproxy
>
>-----Original Message-----
>From: serusers-bounces at iptel.org [mailto:serusers-bounces at lists.iptel.org] On
>Behalf Of Iqbal
>Sent: Friday, February 25, 2005 11:30 PM
>To: serusers at lists.iptel.org
>Subject: [Serusers] nat, symmetric /asymmetric UA....clarification needed
>
>
>Hi
>
>Just trying to debug why some calls work and other dont, I have 2 setups,
>in both the UA is xlite , and is natted in both cases...however the
>routers differ in each case.
>
>Now I am running mediaproxy, when I debug ser, in one setups the contact
>header which is displayed using xlog, shows the external IP address of
>the router, in the other it does not, this happens after I have passed
>the fix_contact setting in ser.cfg.
>
>The one where it is fixed , allows me to listen to voicemail prompt from
>asterisk without any problems, the other...no sound.
>
>The clarification I need is this..
>1. Mediaproxy solves symmetric NAT problems with ease..Y/N ?
>2. For asymmetric stuff you need to add the clients to sip/rtp-asymmetric
>files Y/N ?
>3 If Yes the the client in this case is xlite...which is not really the
>asymmetric part, its the router in the middle is it not ?
>4. If I place slite in the file, will it not then affect the symmetric
>xlite also.
>
>Now if all this fails, can I on the xlite...which seems to be behind the
>asymmetric setup, use STUN server, if yes, then the mediaproxy I guess
>will not get called, or should it.....or is it better to map the
>port/pathsin the router itself.
>
>As a last question, if I wanted to determine what type of NATting a
>device did, or I needed to debug a customers setup, whats the easiest way
>
>tks
>Iqbal
>
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