VoIP over VPN problem


I have a problem to establish call session between two sites over gre tunnel ipsec. The tunnel is up but I am Unable to set a call. I think the problem is Nat but I don't know how to fix it.  It's seems like the traffic were blocked in the beginning of the tunnel.

You can see the configuration files in attached.


Best Regards,


Aristide AkaffouAsked:
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David FavorLinux/LXD/WordPress/Hosting SavantCommented:
Or somewhere along the line of your VPN is blocking either ports or IPs.

Turn off your VPN first + retry.

If this works, turn on your VPN. If you can look at Websites + not make calls, likely this means someone is blocking your VOIP call port from the outdrop (IP) your VPN is using.

You can always connect through another region to get another IP.

Switching regions or just doing a VPN reconnect will likely give you a new IP. If this helps at all, likely this will only help for a while + the block will occur again in the future.

If you're doing this to attempt creating a secure VOIP setup, likely best to switch to a secure VOIP client, where security is handled at the VOIP layer. If you use a secure VOIP client, then you can drop the VPN setup for better call quality, because your connection speed will be higher.
nociSoftware EngineerCommented:
There can be filters on the tunnel blocking some traffic. Check this by doing a tshark/tcpdump/wireshark dump on both side and see what gets accross.
It may very well be routing on the other side has trouble finding the way back...

Lots of if's...
Can you provide  more info on the setup.
( left & right side address ranges, and all possible routing in view.).
The config files seem to be missing from the post.
N. SpearsSr.Net.EngCommented:
If you are using GRE, it sounds like you are using a routed vpn with VTI's. Insure that the routing for your voice traffic is pointed to the tunnel interface or far end of the vpn's tunnel interface.
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N. SpearsSr.Net.EngCommented:
Please post the configuration file. I don't see one attached.
Aristide AkaffouAuthor Commented:
Hi Soulja,
You can see the files in attached.
The network address you have to consider:

For CI: : data vlan Voice vlan public IP address

For Lebanon: data vlan voice vlan ; Public IP address

Best Regards,

N. SpearsSr.Net.EngCommented:
For your vpn, what is the status of your ipsec sa's.

sh crypto ipsec sa

Also what is your eigrp routing looking like

sh ip eigrp neighbors
sh ip route eigrp or sh ip route from the CI router. sh ip route from the  Lebanon router.
Aristide AkaffouAuthor Commented:
Hi Soulja,
The status of sh crypto ipsec sa is idle

EIGRP Adjacency is established I can ping each the two sites.

Best Regards,

N. SpearsSr.Net.EngCommented:
I see the ASA in the diag. Is it allowing your VOIP traffic through. You have a lot of pieces in play in order to troubleshoot this in this forum. Please provide as much detail as possible. You provided the router configs, but there are many more points of failure for connectivity in this scenario.
Aristide AkaffouAuthor Commented:
OK I can provide ASA configuration. I have permitted the traffic in ASA.
Aristide AkaffouAuthor Commented:
Hi Guys,
Any update.

Best Regards,

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