A sender's association is rejected

Symptom: the modality reports association rejected, calling AE title not recognized, or cannot send at all.

Check the turned-away list first

Monitoring › Turned away in the last hour lists every sender the nodes refused, with its calling AE title, address, the AE title it called, the port, and why. A sender turned away also raises an alert.

“No route accepts this sender”

No enabled route’s source matches the sender’s calling AE title, address, called AE title and port all at once. The association is rejected as calling AE title not recognized.

1. Open Configuration › Route tester and enter exactly what the turned-away list shows. It tells you which routes’ sources do not match, and why.
2. Common causes:
   • the calling AE title differs in case or spelling from the source’s (CT_1 vs CT1); wildcards help (CT*);
   • the modality’s address is outside the source’s Remote IP ranges (a new subnet, a NAT, a load balancer in between that hides the sender’s address);
   • the source lists Called AE titles and the modality calls the router something else;
   • the source or its route is disabled.

Rejected as “temporary congestion” or “local limit exceeded”

• Temporary congestion: the node has no configuration yet (it has just enrolled, or is waiting for approval). See A node does not appear.
• Local limit exceeded: the node already has Max inbound associations per node open (Settings). Raise it, add a node, or find the sender that leaves associations open.

Refused for some kinds of images only

A sender may be accepted but refused one kind of image (a SOP class) because none of the transfer syntaxes it proposed is allowed by its source. The turned-away list shows it as transfer syntaxes refused, naming the kind of image and the syntaxes proposed. Allow one of them in the source’s Transfer syntaxes accepted, or set the modality to also offer uncompressed. See Transfer syntaxes.

Nothing reaches the router at all

If the sender is not on the turned-away list, its connection never reached a node: see A sender’s echo fails.