Realpresence 500 Outgoing calls only working - OpenVPN network

[Anonymous]

Hi,

I'm pretty happy with the "realpresence 500" so far and plan to continue recommending it to my clients. The issue I'm having is that I can initiate video calls from my unit to other units over the internet (Site A to B), however calls from the internet to my "realpresence 500" fail to connect (Site B to A). I receive a notification on my unit that an incoming call is connecting and then it just disconnects. On the initiating side (ex. realpresence desktop client at Site B) it shows that the call is connected, but no video or audio is coming through.

My "realpresence 500" is connected directly to a DD WRT router that is acting as an openVPN gateway and incoming port forwarder to the realpresence unit. The tcp/udp ports being forwarded are 1718:1731, 3230:3291 & 5060. ALL traffic from/to the "realpresence 500" is being routed through the VPN. The VPN server (cloud hosted linux server with static ip)  is configured to forward the same aforementioned incoming ports to the DD WRT router through the VPN. External clients dial my VPN server's xx.xx.xxx.xx/23 public IP. The attached quick images shows my network setup & realpresence 500 firewall configuration.

The port checker http://www.yougetsignal.com/tools/open-ports/ shows that the aforementioned ports are open when scanning my VPN server's public IP. Im able to ping the "realpresnece 500" private IP from the VPN server, DD WRT router & other VPN clients. Iptables rules on the openvpn server and DD WRT router are as follows:

OpenVPN server:
iptables -t nat -A PREROUTING -i ens3 -p tcp -m multiport --dports 1718:1731 -j DNAT --to-destination 172.27.232.2
iptables -A FORWARD -i ens3 -d 172.27.232.2/32 -p tcp -m multiport --dports 1718:1731 -j ACCEPT
(...Repeat for the other ports mentioned above, ens3 is external interface, as0t1 is the VPN interface, 172.27.232.2 is the DD WRT router)
iptables -t nat -A POSTROUTING -o as0t1 -j MASQUERADE

DD WRT:
iptables -t nat -A PREROUTING -i tun1 -p tcp --match multiport --dports 1718:1731 -j DNAT --to-destination 192.168.101.100
iptables -I FORWARD -i tun1 -p tcp -d 192.168.101.100 --match multiport --dports 1718:1731 -j ACCEPT
(...Repeat for other ports mentioned above, tun1 is the VPN interface, 192.168.101.100 is the realpresence 500)

At this point im not sure whether its a NATting or realpresence configuration issue. Any tips would be greatly appreciated.

Thanks

[SteffenBaierUK]

Hello JoMo,

welcome to the Polycom Community.

The community's Video contains thes posts here:

• Jun 21,2014 Question: Is there a way I can make a test call to a Polycom site?
  
  Answer: Have a look at this post => here <=

• Jun 21,2014 Question: Are there specific Ports in my firewall that I need to open in order to utilize video conferencing?
  
  Answer: Please check the relevant release notes or admin guide for your device under the section “Inbound and Outbound Ports” or "Port usage" => here <=.
  
  In addition check this FAQ post => here <= for more details and troubleshooting suggestions.

• Jun 21,2014 Question: What could be causing one way video or one way audio when utilizing video conferencing?
  
  Answer: Please check the relevant release notes or admin guide for your device under the section “Inbound and Outbound Ports” or "Port usage" => here <= in order to open the relevant firewall ports.
  
  In addition check this FAQ post => here <= for more details and troubleshooting suggestions.

The above examples include a Wireshark trace so you can verify the ports that are negotiated via H.323 as an example. This is also in a similar way replicable for SIP. Some examples can be found in the VoIP FAQ as well.

Please ensure to provide some feedback if this reply has helped you so other users can profit from your experience.

Best Regards

Steffen Baier

Polycom Global Services

[Anonymous]

Thanks Steffen, looking forward to other members input as well.

[SteffenBaierUK]

Hello JoMo,

pretty simple to troubleshoot.

On your calling device, i.e. RPD, run a wireshark and see what ports are negotiated and span a port on your receiving device and compare what you receive.

Please ensure to provide some feedback if this reply has helped you so other users can profit from your experience.

Best Regards

Steffen Baier

Polycom Global Services