Click Here To Visit SIP Broker  

Go Back   Voxalot / SIP Broker Support Forums > SIP Broker Forums > SIP Broker Support

SIP Broker Support Support for the SIP Broker service.

 
 
 
 
Thread Tools Display Modes
Prev Previous Post   Next Post Next
Unread 09-13-2007, 01:33 AM   #11
martin
 
Join Date: Feb 2006
Posts: 2,930
Thanks: 528
Thanked 646 Times in 340 Posts
martin is a jewel in the roughmartin is a jewel in the roughmartin is a jewel in the roughmartin is a jewel in the roughmartin is a jewel in the roughmartin is a jewel in the rough
Default

Quote:
Originally Posted by 910198 View Post
For the ACK to arrive it is necessary to create some mappings on the firewall. This is simply impossible on public networks.
This is not true. In your case you are expecting the ACK to come back on port 5060 because your device is instructing the other end point to do so via the CONTACT information it is passing in the OK message. This is why you are forced to modify the firewall rules.

Normally when a device is sitting behind a firewall, and using something like STUN, the CONTACT header will contain a front facing port (that the firewall knows to forward to the internal IP) as determined by the STUN protocol. Depending on whether you are sitting behind a full cone NAT, restricted cone NAT, port restricted cone NAT or symmetric NAT router this port can vary (something like 53451 for example).

If you choose not to use STUN or open up your firewall, the other option is to register your device with a server (like Voxalot) that has server based NAT handling. In this case the proxy will do the NAT handling on your behalf and the SIP messaging will be proxied.

As a simple test, turn off NAT handling (this is extremely important) on your device and register it with Voxalot. Using one of the access numbers, dial *010xxxxxx where xxxxxx is your Voxalot number.

In this scenario, you will see the ACK message come from the Voxalot proxy you are registered against. Once again, this is due to the fact that Voxalot is performing the NAT handling on your behalf

So just to re-iterate, if you want to properly receive the ACK message from the other end point, and you are behind a firewall, you must either:

1. Use a protocol like STUN to perform client side NAT handling (Note: STUN is broken in SJPhone and needs to be disabled. Make sure the "Use discovered addresses in SIP" is unchecked. I suspect this is half your problem)
2. Open up your firewall ports and forward to your device
3. Register your device with a proxy that has built-in NAT handling capabilities.
.
__________________
Martin

Please post support questions on the forum. Do not send PMs unless requested.
martin is offline   Reply With Quote
 

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Can this work this way?! andrerio Voxalot Support 2 08-29-2007 06:29 AM
Help getting SipBroker numer to work latinhawk SIP Broker Support 1 07-22-2007 03:27 AM
Calling Blueface No from Voxalot does not work using Grandstream, works from SJ-phone kurun Voxalot Support 0 12-30-2006 07:53 PM
Sticky Topic :: Voip servers that work amroe Voxalot Support 3 10-20-2006 01:18 PM
Can't get call forward to work??? pmerrill Voxalot Support 2 07-14-2006 03:52 AM


All times are GMT. The time now is 11:00 AM.


Powered by vBulletin® Version 3.7.2
Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.