Charles Steinkuehler wrote:
>
> > > ???
> > > Please explain a bit more about exactly what you're trying to
> accomplish...
> >
> > Large medical images -- some approaching gigabyte sizes.
> >
> > The internal network connects multiple facilities. The images may need
> > to be shared across multiple facilities.
> >
> > Our preferred solution is to put one (1) copy of each image on a large
> > and robust fileserver inside their network. The catch is, they are
> > using proprietary systems for viewing and analyzing the images and we
> > may not be granted access nor information adequate to implementing our
> > preferred solution. Currently, the remote sources are using their
> > proprietary systems (black boxes) to auto-magically transfer the files
> > directly to one (1) proprietary system inside our customer's network.
> > Yes, this looks everyway like ftp -- except the proprietary system
> > vendor says, no, it is not that simple ;>
> >
> > When one of these images is needed on another proprietary system inside
> > this network, somebody needs to push the required file to another
> > proprietary system. Our customer wants ``pull'' access from any given
> > system.
> >
> > In brainstorming alternatives, this occured to me:
> >
> > send images
> > |
> > V
> > internet
> > |
> > V
> > firewall
> > |
> > ---------------------
> > | | |
> > V V V
> > host_1 host_2 host_n ...
> >
> > Regardless, whether or not this is the best solution for this
> > application, how can this be done?
>
> Well, it sounds like you're in black-box hell :<
Do I detect a bit of empathy from somebody who's been here before?
> My current understanding of your problem (please correct me if I'm wrong):
>
> - A remote, black-box system pushes images to one black-box system in your
> customer's network (let's call it "Master")
>
> - Your customer can push images from the Master black box system to several
> other black-box systems (Slaves)
>
> - Your customer wants to be able to view images from any slave system w/o
> having to push the file from the master system (ie pull, not push)
Yes -- this pretty much sums it up ;>
> Without an understanding of the black-boxes involved, there's not a lot you
> can do here. If I am now understanding your initial question properly, you
> are asking if it's possible to somehow get the remote system to push the
> image content to multiple systems on your internal network. The simple
> answer is no...there is no straight-forward network slight-of-hand that will
> allow you to trick one system into talking multiple remote systems at the
> same time. The more complex answer is maybe, and depends a lot on unknown
> details of your black-box systems...
Yes, that is core to my question: can port forwarding process do a
``tee'' to multiple addresses?
> I can think of a few things that could potentially help you:
>
> 1) Get the remote system to push the data to all clients. This will chew up
> lots of internet bandwidth, and will either require multiple external IP's,
> or control over which ports are used to connect (assuming you're running a
> masqueraded internal network).
>
> 2) Get the Master internal system to push the data to all slave systems.
> This may be possible to automate, or it may require a "console
> jocky"...depends on unknown (to me) details of your black-box systems.
>
> 3) Whip up a Black-Box emulator, that can talk the file-transfer protocol
> used by your systems. Have your remote system transfer files to your fake
> system, then push the data from there to all internal systems, as required.
> This will require network programming (not too tough in modern languages
> like Java, Perl, Python, &c) and an understanding (or reverse engineering)
> of the file transfer protocols used by your equipment.
>
> 4) Read through the docs for your black-boxes, and see if they support any
> kind of image-server access. I think this is really what you want...a
> central image server. If you're lucky, you can do this with a *nix box. If
> you're unlucky, you'll need a propriatery box from your vendor for the other
> systems. If you're really-really unlucky, there's no support for any kind
> of 'pull' technology on the individual Slave stations.
>
> NOTE that everything but the last option requires lots of storage capacity
> on each image station, since each station is storing copies of all the image
> files.
Yes, these are the alternatives we are considering. Yes, all of these
depend -- more or less -- on access to proprietary information to which
we may or may not be privy ;<
Of course, the image/fileserver approach makes most sense from many
perspectives.
Nevertheless, the port forwarding ``tee'' feasibility is an interesting
question, regardless of our current customer's predicament!
man ipmasqadm, on my potato box, contains and interesting example, which
may or may not shed light on this; but, which I also do *not* fully
understand:
``Redirect all web traffic to internals hostA and hostB, where hostB
will serve 2 times hostA connections. Forward rules already masq
internal hosts to outside (typical).
ipchains -I input -p tcp -y -d yours.com/32 80 -m 1
ipmasqadm mfw -I -m 1 -r hostA 80 -p 10
ipmasqadm mfw -I -m 1 -r hostB 80 -p 20''
What is this really doing?
--
Best Regards,
mds
mds resource
888.250.3987
Dare to fix things before they break . . .
Our capacity for understanding is inversely proportional to how much we
think we know. The more I know, the more I know I don't know . . .
_______________________________________________
Leaf-user mailing list
[EMAIL PROTECTED]
https://lists.sourceforge.net/lists/listinfo/leaf-user
