IP number displayed

[cedi]

Hi everyone.

My first post after nearly 6 months of reading this forum.
I hope I'll get some help with my problem.

I have few Tandbergs (7000, 990, 880, 1000). All have E4.0 SW
When calling through firewall, sometimes the called party gets my internal IP number displayed and not public IP as it should be. When I call to USA or Norway or Danmark it works fine (public IP) but when I call nationaly (in my own country), parties get my local (internal) IP number. Those from my country also can't call in, while those from other countries can. Regardless of far-end codec (Tandberg, Sony, Polycom), it's allways the same.

I have EICON firewall (static NAT, open ports defined by Tandberg). In the codec I have NAT set to "auto".

Thank you for your help.

Regards from Slovenia.

Andrej

[Yukikaze]

It sounds like a routing issue to me. The only way I can see this happening is if your national calls aren't going through the firewall at all. I'm not familiar with that firewall, but if there is a way to see who is trying to make outbound connections it might by beneficial to see if there is any activity there when you make a national call.

[cedi]

Every call, national or international, must go through a firewall.
I don't know why is the internal number forwarded instead of public IP. Is this a codec issue or the firewall?

[BasicITOne]

First question - Are your private IP addresses routable? If they are then you are seeing a NAT configuration issue. If your addresses are in fact "private" non-routable addresses then I would take a hard look at what your system name is on all devices. There are two places to look on through the menu and the other through telnet with the h323alias command.

Private addresses are not routable and would be dropped at the first Internet router -if it even makes it that far. Unless the answer to the next question is yes.

Last question - Are you using VPN tunnels between sites in your country and not between the others?

[cedi]

Hi BasicITOne.

Private addresses are routable. We use NAT-static. Settings should be correct, as I can call in from the Codian MCU (that demo MCU available on the www...).

"System name" on codec corresponds to model. As we have 1 Tandberg 7000. 1 Tandberg 990 and 1 Tandberg 1000, their system names are T 7000, T 990 and T 1000. If you had E.164 alias in mind, it is not set (is empty) as we don't use the gatekeeper. H.323 prefix is also blank.

We don't have any VPN connections.

[Slimey]

have you tryed putting a pc on the same network segment as the video conf machine and doing a traceroute to the addresses you are having trouble with?

[cedi]

Slimey,

I can connect via telnet on to the codec and then make traceroute to addresses. It works fine.

I don't know how could "traceroute" help me with my problem. I can make successful calls, it's just that the party called sees my private IP number not my public IP.
I thought this could be an auto-NAT issue. But it's the same as when I set NAT to "manual".
Incoming calls seem to work fine. I receive callers public IP.

[Slimey]

my mistake i read it wrong
at least it works ;)

[Joe Vallender]

For the issue of outside callers not able to call you, it appears the firewall is not doing the routing the public address called to your internal address or the ports aren't opened properly.

Regarding the number displayed by the far end when you make calls, it would help if you had some sort of sniffer where you could capture the H.323 message containing the SETUP to see what your unit is sending in the two cases. Below is a sample I captured using Ethereal which shows the Q.931 SETUP and the DISPLAY information the originator is sending.

Frame 11 (254 bytes on wire, 254 bytes captured)
Ethernet II, Src: 00:90:ca:00:07:9e, Dst: 00:00:0c:07:ac:04
Internet Protocol, Src Addr: xxx.xxx.xxx.xxx (xxx.xxx.xxx.xxx), Dst Addr: yyy.yyy.yyy.yyy (yyy.yyy.yyy.yyy)
Transmission Control Protocol, Src Port: 3304 (3304), Dst Port: 1720 (1720), Seq: 1, Ack: 1, Len: 200
TPKT
Q.931
Protocol discriminator: Q.931
Call reference value length: 2
Call reference flag: Message sent from originating side
Call reference value: 342D
Message type: SETUP (0x05)
Bearer capability
Information element: Bearer capability
Length: 4
...0 1000 = Information transfer capability: Unrestricted digital information (0x08)
.00. .... = Coding standard: ITU-T standardized coding (0x00)
1... .... = Extension indicator: last octet
...1 1000 = Information transfer rate: Multirate (64 kbit/s base rate) (0x18)
.00. .... = Transfer mode: Circuit mode (0x00)
0... .... = Extension indicator: information continues through the next octet
Rate multiplier: 131
...0 0101 = User information layer 1 protocol: Recommendation H.221 and H.242 (0x05)
1... .... = Extension indicator: last octet
Display
Information element: Display
Length: 11
Display information: Polycom MGC
Calling party number
Information element: Calling party number
Length: 17
.... 0001 = Numbering plan: E.164 ISDN/telephony numbering (0x01)
.010 .... = Number type: National number (0x02)
1... .... = Extension indicator: last octet
Calling party number digits: 2787933314000207
User-user
Information element: User-user
Length: 150
Protocol discriminator: X.208 and X.209 coded user information
H.225.0 CS