asterisk users - Apr 2005 - SIP registration behind Linksys WRT54G

Hello,

I'm having some major problems getting SIP phones to register whenever I put
them behind a Linksys router. The same phones will register behind any other
NAT (I've tried 3 others without problems)

I've been debugging using Ethereal and these are the differences that I
found between Linksys WRT54G and a Monowall Router as an example (Monowall
router is one of the many that work fine for me):

REGISTER sip:asterisk.mydomain.com

	Monowall (good registration)

	- Via: SIP/2.0/UDP 192.168.10.199;branch=...
	- Authorization: DIGEST ..., uri="sip:asterisk.mydomain.com", ...
	- Contact <sip: 204@192.168.10.199;user=phone>

	Linksys WRT54G (Bad registration - 403 Forbidden)
	
	- Via: SIP/2.0/UDP 66.x.x.166;branch=...
	- Authorization: DIGEST ..., uri="sip 66.x.x.166:5060", ...
	- Contact *


As you can see the difference seems to be that with the Linksys the SIP
request has it's WAN IP + port (66.x.x.166) whereas the request from behind
a monowall has the LAN IP of the phone 

What is the explanation for this difference?  Needless to say - I don't have
any special port forwarding enabled on either one of these routers and I'm
using the identical phone with identical configuration for both tests.

I have outgoing proxy in my phone's configuration but it almost looks like
it's disregarding that option when behind the Linksys router.  

Another interesting thing to note is that I have tried connecting to some
other proxy from behind Linksys (not my own asterisk but some other provider
- I don't know what they are running)  I was able to register without a
problem.  Interestingly, the registration request looked identical to the
monowall one (Via: LocalIP , uri: FQDN ) ... unfortunately because I am not
the system admin on that VoIP server I can't login to see what configuration
they have in order to copy it.

I'm really out of ideas ... if anyone has any hints of what else I could
check out I would really appreciate that.

Thank you,
Tomas

Please make sure you post any solution you find to this issue to the 
list I have been frustrated by this as well.

Scott Henderson
===========================================================================Finite
Technologies Incorporated
3763 Image Drive, Anchorage, Alaska 99504
Phone: 907.339.8085 ext 6101, Fax: 907.333.4482
http://www.finite-tech.com
http://www.chillywall.com
http://www.virtuale.cc
http://www.mphage.com
Current Local Time: http://www.worldtimeserver.com/time.asp?locationid=US-AK
===========================================================================


Tomas Florian wrote:
>Hello,
>
>I'm having some major problems getting SIP phones to register whenever I
put
>them behind a Linksys router. The same phones will register behind any other
>NAT (I've tried 3 others without problems)
>
>I've been debugging using Ethereal and these are the differences that I
>found between Linksys WRT54G and a Monowall Router as an example (Monowall
>router is one of the many that work fine for me):
>
>REGISTER sip:asterisk.mydomain.com
>
>	Monowall (good registration)
>
>	- Via: SIP/2.0/UDP 192.168.10.199;branch=...
>	- Authorization: DIGEST ..., uri="sip:asterisk.mydomain.com", ...
>	- Contact <sip: 204@192.168.10.199;user=phone>
>
>	Linksys WRT54G (Bad registration - 403 Forbidden)
>	
>	- Via: SIP/2.0/UDP 66.x.x.166;branch=...
>	- Authorization: DIGEST ..., uri="sip 66.x.x.166:5060", ...
>	- Contact *
>
>
>As you can see the difference seems to be that with the Linksys the SIP
>request has it's WAN IP + port (66.x.x.166) whereas the request from
behind
>a monowall has the LAN IP of the phone 
>
>What is the explanation for this difference?  Needless to say - I don't
have
>any special port forwarding enabled on either one of these routers and
I'm
>using the identical phone with identical configuration for both tests.
>
>I have outgoing proxy in my phone's configuration but it almost looks
like
>it's disregarding that option when behind the Linksys router.  
>
>Another interesting thing to note is that I have tried connecting to some
>other proxy from behind Linksys (not my own asterisk but some other provider
>- I don't know what they are running)  I was able to register without a
>problem.  Interestingly, the registration request looked identical to the
>monowall one (Via: LocalIP , uri: FQDN ) ... unfortunately because I am not
>the system admin on that VoIP server I can't login to see what
configuration
>they have in order to copy it.
>
>I'm really out of ideas ... if anyone has any hints of what else I could
>check out I would really appreciate that.
>
>Thank you,
>Tomas
>
>
>
>_______________________________________________
>Asterisk-Users mailing list
>Asterisk-Users@lists.digium.com
>http://lists.digium.com/mailman/listinfo/asterisk-users
>To UNSUBSCRIBE or update options visit:
>   http://lists.digium.com/mailman/listinfo/asterisk-users
>  
>