[AG-TECH] Fwd: Access Grid
Robert Olson
olson at mcs.anl.gov
Tue Oct 28 12:23:42 CST 2003
One difference between vic and rat is that rat binds the source port to be
the same as the destination port, while vic uses a random (system-assigned)
port as the source port. Perhaps this has an effect on what happens with
the NAT bridging:
12:15:43.142386 lorax.mcs.anl.gov.1422 > 224.1.2.3.12000: udp 449
--bob
At 11:41 AM 10/28/2003, John I Quebedeaux Jr wrote:
>I'll let better minds tackle the details but will throw in my 2 cents and
>say that last Friday I found myself in a situation with our quick bridge
>and a NAT'd address where the RAT worked fine but the VIC did not connect
>for video coming back to the bridged machine (our portable AG node
>nicknamed "Wilbur"). Thankfully, the network folks at the site understood
>the dilemma and without any fuss went ahead and moved me outside their
>firewall and let me borrow a static address so I could continue the setup
>for 90 minute demo that evening.
>
>The network admin could tell me that the VIC connection wasn't getting
>established back from the bridge through the NAT'd address so only
>outgoing video was working. RAT didn't have a problem. The static address
>took care of the issue, we were short on time to troubleshoot.
>
>So, the symptom was: everyone could see me and I was blind for about 30
>minutes while we worked this out. I was on a NAT'd address behind a
>firewall. They had setup ports 50012/50013 -RAT, 50014/50015 -VIC, 5001
>DPPT for me to get through the firewall.
>
>-John Q.
>--
>John I. Quebedeaux, Jr.
>Computer Manager / Louisiana Biomedical Research Network
>LSU Biological Sciences / 131 Life Sciences
>e-mail: johnq at lsu.edu / web: http://lbrn.lsu.edu
>phone: 225-578-0062 / fax: 225-578-2597
>
>On Oct 28, 2003, at 10:17 AM, Sheryl Hurley wrote:
>
>>
>> Hi everyone,
>> I thought I'd send this to the AG Tech list, to see if anyone has
>> any helpful suggestions for the Digital Pueblo people. I am not
>> sure what their problem is.
>>
>> Thanks,
>> Sheryl
>>
>> Begin forwarded message:
>>
>> From: Glenn A Huval <magius at unm.edu>
>>
>>
>>
>>
>> Hello everyone,
>>
>> As Hue already mentioned, we are going to be heading up to SFCC
>> early on Wednesday (2:30 roughly). Sheryl has volunteered to
>> come with us to Santa Fe and work with CY (who will be over at
>> HPC in Albuquerque).
>>
>> So here's the setup, for those who don't know.... The
>> QuickBridge is being ran at HPC. Both Brad (at NHCC) and I (at
>> SFCC) are connecting to the QuickBridge through ports 50372 and
>> 50374. Brad gets Audio and Video from my site and anyone else
>> connected to the bridge, and I get nothing (I do see myself,
>> though I'm not sure of the significance of that).
>>
>> Now we think we can solve this by forwarding ports 50372 and
>> 50374 (UDP and TCP) to some static IP address that we can
>> access from the Media Lab with the laptop. I know the people
>> working on the firewall said they already opened the ports...
>> but since all the IP addresses at SFCC are local only, there is
>> no way to communicate through those ports from the outside, so
>> by open that must mean for connections initiated from inside.
>> I'm still unsure about the network setup there at SFCC though,
>> I was told it's a firewall, but I get the impression it's
>> actually a NAT router or some kind of NAT setup... if it is a
>> NAT then we definitely have to forward the ports. I know
>> normal programs can get through a NAT no problem (most requests
>> initiated from inside are let through), but I think the
>> QuickBridge.
>>
>> The one thing we aren't sure of is whether or not the
>> QuickBridge is trying to send the video and audio back to the
>> SFCC router/firewall, or back to the local IP
>> (192.168.xxx.xxx). If it's going to the router, then
>> forwarding should work... if it isn't I think we are SOL. This
>> is what we should find out on Wednesday....
>>
>> Maybe we can have those ports forwarded by Wednesday 2:30? Or
>> perhaps an explanation of the network if SFCC isn't running a
>> NAT at all?
>>
>> Glenn >=O
>>
>> P.S. For those aware, if I got something wrong about the AG or
>> the possible solution please e-mail something out. Hate to be
>> giving faulty info.
>>
>>
>> -Sheryl Hurley
>> -Multimedia Development Specialist
>> -HPC at UNM
>> -505.277.5460
>>
>>
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