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Appendix D. NAT/Firewall Traversal
There are two possibilities in which a call must traverse a firewall: when the VidyoGateway is
behind a NAT/firewall and when the Legacy device is behind a firewall.
When the VidyoGateway resides on the public network with a native public IP address and
when the Legacy device is behind a NAT/firewall, the Legacy device must open the required
H.323 or SIP ports (whichever are being used).
When the VidyoGateway is behind a firewall and/or within a DMZ, you must configure your
firewall with a STATIC NAT (an external IP address routed to the VidyoGateway native private
address) and open the required ports in both directions.
Configure your NAT Public IP Address. For more information, see
Configuring a Public IP
Address
.
The following diagram illustrates the call flow from a Legacy endpoint calling Vidyo users when the
VidyoGateway is behind a NAT/firewall.
The following list explains each number in the “Calling from Legacy to Vidyo” illustration above.
1.
The Legacy device calls the VidyoGateway public-facing IP address.
2.
The VidyoGateway sends commands to the VidyoPortal.
3.
VidyoManager (on the VidyoPortal) sends the VidyoGateway the VidyoRouter address to
use for calls.
4.
The VidyoGateway establishes a TCP session (17990) with the VidyoRouter. H.264 SVC
media streams (audio/video) are sent over UDP between the VidyoGateway and
VidyoRouter.
Private
Public
Calling from Legacy in to Vidyo
Internet
Legacy
Device
Vidyo
User
VidyoPortal
VidyoGateway
VidyoRouter
Legacy
Device
1
2
3
4
5
192.168.1.110
(private address)
200.100.50.25
(public address)