Symmetric NAT Handling Disabled = break SIPBroker

ladude626 · 02-20-2009, 09:24 PM

I'm current using SIP Broker as my VOIP for dialing 1800 numbers. When I set Symmetric NAT Handling to YES, I can make these calls but when I set it to NO I have no Incoming audio. I've successfully made calls with other providers when turned OFF Symmetric NAT Handling and audio optimization ON. Any else experiencing this problem?

boatman · 02-20-2009, 10:04 PM

What kind of SIP user agent do you have?

Verify that your sip device/software is sending an SDP packet with your public IP address, not your LAN IP address. The problem may not occur with other providers who proxy all the voice traffic, or take measures to correct for having the LAN IP address in the SDP packet's "Connection Information" line.

Try using a STUN server.

If you prefer not to use a STUN server then do the following:
1. In your SIP client, set STUN Enable: no
2. In your router, forward the SIP ports and the RTP port range to your SIP ATA/phone.
3. In order for the ATA/phone to know it's public IP address, make sure the ATA/phone is registered with at least one SIP registrar, or enter the public IP address into the appropriate setting in the ATA (in Linksys ATAs this setting is EXT_IP).

ladude626 · 02-20-2009, 10:33 PM

I'm using the X-Lite softphone. I've set up both Port forwarding on my router (port 5060-5080 and 10000-20000) as well as using stun.voxalot.com STUN server. What can I use to detect if my public IP is set in the SDP packet?

boatman · 02-20-2009, 11:03 PM

There may be some logging option in X-Lite that would show SIP packets. Wireshark is packet monitoring program that works well. If you send me your Voxalot number I can call you and see what Wireshark shows.

ladude626 · 02-21-2009, 02:19 AM

I got the call. Any information from it? And I just want to add that I only have this problem with outgoing calls. Incoming calls seem to work fine.

boatman · 02-21-2009, 03:24 AM

I captured an SDP packet but still not sure what's going on. To which Voxalot proxy are you registering? Is your softphone using TCP transport? UDP transport is normally used for SIP and RTP packets.

02-20-2009, 09:24 PM	#1
ladude626 Junior Member Join Date: Feb 2009 Posts: 15 Thanks: 0 Thanked 2 Times in 2 Posts	Symmetric NAT Handling Disabled = break SIPBroker I'm current using SIP Broker as my VOIP for dialing 1800 numbers. When I set Symmetric NAT Handling to YES, I can make these calls but when I set it to NO I have no Incoming audio. I've successfully made calls with other providers when turned OFF Symmetric NAT Handling and audio optimization ON. Any else experiencing this problem?

02-21-2009, 02:19 AM	#5
ladude626 Junior Member Join Date: Feb 2009 Posts: 15 Thanks: 0 Thanked 2 Times in 2 Posts	I got the call. Any information from it? And I just want to add that I only have this problem with outgoing calls. Incoming calls seem to work fine. Last edited by ladude626; 02-21-2009 at 02:25 AM.

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02-20-2009, 10:04 PM	#2
boatman Senior Member Join Date: Jul 2007 Location: Oregon, USA Posts: 365 Thanks: 17 Thanked 77 Times in 64 Posts	What kind of SIP user agent do you have? Verify that your sip device/software is sending an SDP packet with your public IP address, not your LAN IP address. The problem may not occur with other providers who proxy all the voice traffic, or take measures to correct for having the LAN IP address in the SDP packet's "Connection Information" line. Try using a STUN server. If you prefer not to use a STUN server then do the following: 1. In your SIP client, set STUN Enable: no 2. In your router, forward the SIP ports and the RTP port range to your SIP ATA/phone. 3. In order for the ATA/phone to know it's public IP address, make sure the ATA/phone is registered with at least one SIP registrar, or enter the public IP address into the appropriate setting in the ATA (in Linksys ATAs this setting is EXT_IP).

02-20-2009, 10:33 PM	#3
ladude626 Junior Member Join Date: Feb 2009 Posts: 15 Thanks: 0 Thanked 2 Times in 2 Posts	I'm using the X-Lite softphone. I've set up both Port forwarding on my router (port 5060-5080 and 10000-20000) as well as using stun.voxalot.com STUN server. What can I use to detect if my public IP is set in the SDP packet?

02-20-2009, 11:03 PM	#4
boatman Senior Member Join Date: Jul 2007 Location: Oregon, USA Posts: 365 Thanks: 17 Thanked 77 Times in 64 Posts	There may be some logging option in X-Lite that would show SIP packets. Wireshark is packet monitoring program that works well. If you send me your Voxalot number I can call you and see what Wireshark shows.

02-21-2009, 03:24 AM	#6
boatman Senior Member Join Date: Jul 2007 Location: Oregon, USA Posts: 365 Thanks: 17 Thanked 77 Times in 64 Posts	I captured an SDP packet but still not sure what's going on. To which Voxalot proxy are you registering? Is your softphone using TCP transport? UDP transport is normally used for SIP and RTP packets.