Additional routing considerations, Transmission processors and drive mapping, Factors affecting routing speed – Vista Imaging Vista Routing User Manual
Page 74: Routed images vs. routed exams

Troubleshooting Routing
Routing User Guide
Additional Routing Considerations
Transmission Processors and Drive Mapping
For each Imaging destination that it sends exams to, the transmission processor will map
a drive using the following progression of drive letters: Q – Z, then G – P. If a drive
letter (Q, for example) is not available, it will move to the next letter (R, for example) and
so on. When all entries for a particular destination have been processed, the applicable
drive is unmapped. This logic is not used for DICOM destinations.
Factors Affecting Routing Speed
Given a T1 connection and a light to moderate amount of network traffic, the first images
in a routed exam will typically begin arriving at a destination within minutes. However,
any of the following can impact the delivery of routed exams:
A backlog of images at the Image Gateway, which is responsible for adding entries to
the rule evaluation queue.
A backlog of entries in the transmission queue. If numerous large exams are flagged
for routing in a brief period of time, there will be a delay while all the images in the
exam are transmitted. In situations where multiple destinations are being used,
additional transmission processors may be used to alleviate delays. For more
information, see page
.
Problems connecting to destinations. For Imaging destinations, the routing software
will attempt to re-connect or retransmit the number of times specified for each
destination in the
NETWORK LOCATION
File (#2005.2). For DICOM destinations, retry
attempts are part of the DICOM transmission protocol. Failed connection or
transmission attempts are logged by the Routing Gateway.
The routing priority of a particular exam. For more information, see page
Routed Images vs. Routed Exams
The Routing Gateway evaluates and transmits data on an image-by-image basis. If the
transmission processor is disabled when an exam is partially transmitted, the exam is
usually treated as “unrouted” until the transmission processor is re-started, and the
transmission of the exam is completed.
In some situations, such as the presence of multiple Image Gateways or the use of
on-demand routing, images from one exam will “interrupt” the transmission of images of
an exam that is partially routed. This can occur because entries are added to the rule
evaluation and transmission queues for each image, rather than for each exam. Usually,
this behavior is invisible to the end user.
If a partially routed exam is opened from VistARad, the VistARad software will first
attempt to retrieve images from the local storage location identified in the MAGJ.INI file
VistA Imaging V. 3.0, Patch 18
April 2006
66