Problem with OrthanC behind a proxy, windows machine

Hi all

Problem:
1. OrthanC is running on client machine with a proxy, and receiving images from modalities okay
2. Proxy settings dont allow machine to ping but machine can browse any web address (on proxy whitelist)
3. OrthanC cannot upload to cloud PACS, gives error

I need a solution for OrthanC to work behind the Proxy and be able to send to cloud PACS asap.

Any advise, tips, solutions or IT contacts than can help, please let me know.

regards

Ten

What logs are Orthanc producing when you try and upload to your cloud PACS?

it says Dicom store failed. Do u want to see the logs?

Dear Ten,

It is very hard to help you without having more information about the exact configuration of your system. What kind of proxy are you talking about (Web proxy, SSH proxy, Apache reverse proxy,…)? What is the manufacturer of this proxy? How is your client machine using the proxy? What is your network topology in your intranet? What is your “cloud PACS”?

You should first test your workflow on a computer that does not involve any proxy (e.g. on your computer at home). It is indeed possible that the proxy is not at all a component of the problem.

For instance, if you try and upload DICOM files via the DICOM protocol from inside your intranet to a cloud-based PACS, this approach will most probably fail. Indeed, the DICOM protocol might be filtered by some firewall at the outer frontier of your Intranet. Furthermore, upload via the DICOM protocol will not be enabled by a Web/HTTP proxy (as those are not the same protocols).

I suggest you to get in touch with your network administration team to track down the problem.

The only recommended way to send DICOM files between two remote sites via Internet is to use the REST API of Orthanc… which of course implies that your cloud PACS is Orthanc itself.

HTH,
Sébastien-

Dear Sebastian

Thank you for your response. Apologies not really an IT pro hence the lack of detail. But answers as follows:

  1. Webproxy, unknown manufacture, but can findout.
  2. Computer is on a Lan with static IP, all internet traffic goes thru prox at their HQ. Computer is on whitelist, can browse any website but cannot ping
  3. Cloudpacs is DCM4CHEE
  4. Yup tested workflow on home computer, sending to cloud with orthanc okay no problem. Fails to send on client comp b/c of proxy issue. Another commercial DICOM gateway is having same problem
  5. You are right its failing to send DICOM from inside the intranet

So if use REST API of OrthanC it will send from inside the proxy?

regards

Ten

Hello,

OK, I think this confirms my rough guess: Your proxy enables your computer to do requests using the HTTP/HTTPS protocol to the outside world (i.e. bypass the firewall rules of your institution), but not to do requests using the DICOM protocol. DICOM is visibly blocked by your firewall.

At this point, you have 2 possibilities:

  1. Ask your network administrators to put your computer on the whitelist of their firewall for the DICOM protocol. This is clearly NOT recommend, as it implies security problems: The DICOM protocol should only be used in intranets.
  2. Replace your cloud PACS with Orthanc, and send DICOM files through the HTTPS protocol (which would be OK thanks to your proxy). If you still wish to use Dcm4Chee, you could install Orthanc in your cloud setup, so that every file that is received by Orthanc is auto-routed to Dcm4Chee.

HTH,
Sébastien-

Hi Sebastian

We have done number 2, and we now need to configure orthanc at client site to send to orthanc in cloud and thats what we are working on. Will update or reachout with any issues that arise.

Thank you.

Tennyson

HI Sebastien !

How can I tell OrthanC to use a proxy or will it use the systems (windows) default proxy ?

There is no way to directly configure a HTTP proxy inside Orthanc.

Actually, I do not know whether Orthanc (that is built upon libcurl) will use the default HTTP proxy of Windows.

If this is not the case, I certainly can add a configuration option for the next release. Could you make some test?

Hello,

I have just added a configuration option to make Orthanc use a HTTP proxy. This option is called “HttpProxy”:
http://goo.gl/KIwWlZ

You can download a development snapshot for Windows in SourceForge:

https://sourceforge.net/projects/orthancserver/files/DevelopmentSnapshots/

Arnold, would it be possible for you to make some test?

HTH,
Sébastien-