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Do I need VCS-E Dual Network Option?

Hi all,

I need to deploy a VCS-E and an SX20 in a network as attached.

Upon configuring traversal zone between VCS-C and VCS-E, VCS-C indicates that it establishes traversal zone without any error.

But VCS-E indicates "Warning" and it says "Systems unreachable".

There is no closed port between them so I don't think this is not caused by NAT router ( in this test we use netscreen firewall instead of NAT router).

I think the reason for this issue would be that VCS-E does not have Dual Network Option, even though I don't use LAN2 on VCS-E.

Is it correct?

Best Regards,

Kotaro Hashimoto


Do I need VCS-E Dual Network Option?

Hi Hashimoto Kotaro,

even though you don't use second nic on the VCS-E, you still need a dual nic option key if you using NAT in your enviornment.

As said earlier dual nic option keys serve two purpose:

- allows to configure static nat address on the VCS

- enable second nic on the VCS

from your excel sheet it looks as if you are using nat on VCS and VCS-E and MCU ? is my understanding correct?

can you explain the network deployment you have?



Do I need VCS-E Dual Network Option?

The drawing is also not really clear for me.

In theory it can be that you do not need a dual interface option.

If I understand it right, there is no NAT within the network. Thats fine.

What I do not undestand is:

Static Nat




SX20 ⇔

The only devices which need to communicate with each other are

MCU <-> VCS-C (and other video systems in the 172.16 network without nat)

VCS-C >NAT> VCS-E (outbound from -C to -E and the answers back in, but no new connections from -E to -C)

SX20 <-> VCS-E (or other video systems to the -E)

If the SX20 dials the mcu it only communicates with the VCS-E which will send signaling and media to the VCS-C

which sends it to the MCU, no need to have a communication path directly in between the different networks.

Thats the main intention in a VCS-C+E deployment, only one path in between different networks.

If you have some public ip addresses on the outside and you need to NAT this to your 10.x.x.x ips

you would need to have the dual interface option on the VCS-E.

On the traversal zone on the VCS-C you would set up the ip that would work fine with

or without NAT. If you have a NAT where you need to point the traversal zone to the

you would need the dual interface option to enable inbound NAT for the VCS-E

But then you also would need to either register the SX20 to as all communication to that

interface then has to go to the configured NAT ip, but then you could use an addtional transfer network

and utilize the second network port.

But the easiest is really just have NAT just for >NAT> so the VCS-C can

reach the real interface IP of the VCS-E. (given that you do not need public connectivity on the -e)

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