Please Help!! (I can't videochat)

Question

I have been trying to solve this for a week now, and I just dont know what's wrong! Please someone help me.
The problem started whan I changed my ISP (I changed from dsl to cable connection). The problem is that I can not video conference with one person (starting a video chat with this person did not represented a problem before, and he did not made any changes to his network). First I tried all possible port openning combinations in my router without any success. Finally, I decided to plug my cable modem directly to my computer to see if it worked. To my surprise, when I pluged the modem directly to my computer I was able to start videochat with the three apple tests (appleu3test01, appleu3test02 and appleu3test03), but starting a videochat with my friend did not work. I tried sending him the video request and he tried sending me the request without any success.
My modem is a: Motorola surfboard SB5101
Now, here comes the interesting part...
In the network system preferences I have noticed that my assigned IP is not my "public ip" (it is like if I was connected to a router, but I am not). Also, the ip assigned to me and the "router address" are not the ones that the motorola surfboard assigns. It looks like my ISP is assigning me directly these numbers and it was like if I was connected to a router that THEY control.
To make the scenario more clear: the motorola surfoard modem has an internal "DHCP server" and if I connect to the modem (but I disconnect the the coaxial cable from the modem) then my computer gets the ip address asigned by the modem which is: 192.168.100.11 Then, If I connect the coaxial cable to the modem my ip is changed to: 10.143.10.2, and the router address (or default gateway) is set to: 10.143.0.1 Now, this is not my public IP address as I stated earlier. This is some numbers my ISP is automatically assigning. Turning off the DHCP server in the modem does not seems to make any change in that matter.
I do not have any software firewall, the OSX firewall is turned off too. I do not know what is wrong with the connection. The thing that bugs me is that I can see the apple tests, and my friend can see the apple tests.. also my friend has videochatted with other person succesfully, but I CAN NOT see my friend in the videochat. iChat gives me an error -8.
My first thought was that my ISP is blobking ports or something like that, but then why can I videochat with the appletests? Also the thing that bnothers me is that I can use other applications like a file sharing program, and I can use the video function of skype too! so why iChat is the onlye app that does not work??? and why does it works with the apple tests but not woth the person I need to talk?? (and the worst thing is that before changing my ISP, I was able to talk to him) so the only logical explanation is that it must be some configuration on the ISP side. I really dont know what to do, If I call my ISP I do not have a clue what to tell them because I do not know what the problem is. They won't even know what iChat is... and they will probably tell me they are not blocking anything. Maybe if I knew the exact problem then i could tell them. But the thing I can;t undesrtand is that if they were blocking the ports then I would not be able to videochat with tha appletests, but I can.
Here is the log of the error I get when trying to chat with my friend (This is the reduced version, if the complete version is needed please tell me and I'll post it):
Date/Time: 2007-04-25 09:16:20.177 -0500
OS Version: 10.4.9 (Build 8P135)
Report Version: 4
iChat Connection Log:
AVChat started with ID 55830311.
[email protected]: State change from AVChatNoState to AVChatStateWaiting.
0x18aed1c0: State change from AVChatNoState to AVChatStateInvited.
0x18aed1c0: State change from AVChatStateInvited to AVChatStateConnecting.
[email protected]: State change from AVChatStateWaiting to AVChatStateConnecting.
[email protected]: State change from AVChatStateConnecting to AVChatStateEnded.
Chat ended with error -8
0x18aed1c0: State change from AVChatStateConnecting to AVChatStateEnded.
Chat ended with error -8
Video Conference Error Report:
4.006397 @:0 type=4 (00000000/48)
[VCSIP_INVITEERROR]
[19]
4.005972 @SIP/SIP.c:2447 type=4 (900A0015/48)
[SIPConnectIPPort failed]
2.004426 @SIP/SIP.c:2447 type=4 (900A0015/48)
[SIPConnectIPPort failed]
Video Conference Support Report:
3.505718 @SIP/Transport.c:1218 type=1 (00000000/0)
[INVITE sip:[email protected] SIP/2.0
Via: SIP/2.0/UDP 10.143.2.109;branch=z9hG4bK102bfb60174d5268
Max-Forwards: 70
To: "u0" <sip:[email protected]>
From: "[email protected]" <sip:[email protected]>;tag=807872548
Call-ID: 7dff23c0-f337-11db-96cb-806612fb13c4@lip
CSeq: 1 INVITE
Contact: <sip:[email protected]>;isfocus
User-Agent: Viceroy 1.2
Content-Type: application/sdp
Content-Length: 540
v=0
o=nkd 0 0 IN IP4 10.143.2.109
[email protected]
c=IN IP4 10.143.2.109
b=AS:2147483647
t=0 0
a=hwi:288:2:2000
a=bandwidthDetection:YES
a=iChatEncryption:NO
m=audio 16386 RTP/AVP 12 3 0
a=rtcp:16387
a=rtpmap:3 GSM/8000/1
a=rtpmap:0 PCMU/8000/1
a=rtpID:1102266615
m=video 16384 RTP/AVP 126 34
a=rtcp:16385
a=rtpmap:126 X-H264/90000
a=rtpmap:34 H263/90000
a=fmtp:34 imagesize 1 rules 30:352:288
a=framerate:30
a=RTCP:AUDIO 16387 VIDEO 16385
a=pogo
a=fmtp:126 imagesize 0 rules 30:320:240:320:240
a=rtpID:1171021812
2.505411 @SIP/Transport.c:1218 type=1 (00000000/0)
[INVITE sip:[email protected] SIP/2.0
Via: SIP/2.0/UDP 10.143.2.109;branch=z9hG4bK102bfb60174d5268
Max-Forwards: 70
To: "u0" <sip:[email protected]>
From: "[email protected]" <sip:[email protected]>;tag=807872548
Call-ID: 7dff23c0-f337-11db-96cb-806612fb13c4@lip
CSeq: 1 INVITE
Contact: <sip:[email protected]>;isfocus
User-Agent: Viceroy 1.2
Content-Type: application/sdp
Content-Length: 540
v=0
o=nkd 0 0 IN IP4 10.143.2.109
[email protected]
c=IN IP4 10.143.2.109
b=AS:2147483647
t=0 0
a=hwi:288:2:2000
a=bandwidthDetection:YES
a=iChatEncryption:NO
m=audio 16386 RTP/AVP 12 3 0
a=rtcp:16387
a=rtpmap:3 GSM/8000/1
a=rtpmap:0 PCMU/8000/1
a=rtpID:1102266615
m=video 16384 RTP/AVP 126 34
a=rtcp:16385
a=rtpmap:126 X-H264/90000
a=rtpmap:34 H263/90000
a=fmtp:34 imagesize 1 rules 30:352:288
a=framerate:30
a=RTCP:AUDIO 16387 VIDEO 16385
a=pogo
a=fmtp:126 imagesize 0 rules 30:320:240:320:240
a=rtpID:1171021812
Another strange thing that happened is that with the default nameservers of my ISP I was not being able to videochat with one of the appletests so I changed to another dns's and then I was being able to videochat with that apple test.. I think that is really strange. I mean, what does the dns's have to do with ichat. I thought they were just for internet addreesses.
Anyone can help me??????

Answer 1

Hi,
router address (or default gateway) is set to: 10.143.0.1 Now, this is not my public IP address as I stated earlier.
If this is not your ISP which it should not be if it is an Internet company rather than a chap claiming to sell Internet connections and in fact sharing his connection - then you need to find out who and where your new modem is connection to.
From Network Utilty on your Mac
Whois has started ...
% This is the RIPE Whois query server #2.
% The objects are in RPSL format.
% Rights restricted by copyright.
% See http://www.ripe.net/db/copyright.html
% Note: This output has been filtered.
% To receive output for a database update, use the "-B" flag
% Information related to '10.0.0.0 - 10.255.255.255'
inetnum: 10.0.0.0 - 10.255.255.255
netname: IANA-ABLK-RESERVED1
descr: Class A address space for private internets
descr: See http://www.ripe.net/db/rfc1918.html for details
country: EU # Country is really world wide
org: ORG-IANA1-RIPE
admin-c: RFC1918-RIPE
tech-c: RFC1918-RIPE
status: ALLOCATED UNSPECIFIED
remarks: Country is really worldwide
remarks: This network should never be routed outside an enterprise
remarks: See RFC1918 for further information
mnt-by: RIPE-NCC-HM-MNT
mnt-lower: RIPE-NCC-HM-MNT
source: RIPE # Filtered
6:33 PM Wednesday; April 25, 2007