Additional Topics > Medical Imaging in IDL > Using IDL DICOM Network Services > Troubleshooting a Retrieval Operation

## Troubleshooting a Retrieval Operation

There are common configuration errors that can lead to retrieval problems. If one of the following errors appear in the Status window of the Query Retrieve SCU tab, consider the following possible resolutions:

Error | Resolution
Move destination unknown. | The remote machine does not recognize the retrieve Destination Node. Try these steps: Make sure that your current Storage SCP Application Entity is selected in this droplist. This is described in Query the Remote Node. Echo the Storage SCP Application Entity to verify valid network connection settings. See Returning Connection Status with Echo. Try to send a file to the Storage SCP directory by selecting a local directory containing any DICOM file and sending it to yourself using the Storage SCU functionality. See Sending Files to a Remote Destination for details.
Unable to process error. | If all of the resolutions in the previous steps work correctly, the problem is likely with the configuration of the your Storage SCP Application Entity information on the remote machine. Check these settings on the machine you are attempting to query. See Defining a Machine to Be Queried for more information. If you are running Windows XP service pack 2, the firewall that is automatically started is likely blocking incoming DICOM packets. See Allowing File Transfer with a Windows XP Firewall for ways to modify your firewall settings.
Files do not appear in the specified directory. | Restart the Storage SCP service. After making any changes to the configuration properties of a Storage SCP Application Entity while in system configuration mode (when the DICOM Network Services utility is started with `DICOMEX_NET, /SYSTEM`), you must stop and restart the Storage SCP Service. Use the Stop Service and the Start Service buttons on the Configuration tab. See Managing the Storage SCP Service for details.

Note: If you are unable to retrieve files, verify that virus scanning software is not blocking the transfer. If file transfers are extremely slow, you may want to disable any virus scanning software when performing query, retrieve or send operations.

### Allowing File Transfer with a Windows XP Firewall

By default, Windows XP service pack 2 automatically starts a firewall. This blocks DIOCM file packet transfer until you either modify your firewall settings or disable the firewall.

To modify your firewall settings to include the port number associated with your IDL_AE_STOR_SCP Application Entity (as defined in Configuring Your System to Receive Files), complete the following steps.

1. Select Start > Control Panel > Windows Firewall.
2. Click on the Exceptions tab and add the port number of entity associated with your Store SCP application entity. Select Add Port and enter a name identifying the port and the port number. If you accepted the default settings for the IDL_AE_STOR_SCP Application Entity, the port number is 2510.
3. Click OK to save the changes and OK to exit the dialog.

You also have the option to completely disable the firewall, although this should be done only if there is low risk of infection from viruses or other external attacks. To disable your firewall, select Start > Control Panel > Windows Firewall and choose Off. Click OK to save the changes and exit the dialog.