sip2: "Failed to process message"; "97" resend; "Wrote 0 Bytes"

Description

We are trying to implement sip2.  The self-check machine shows: 
14:47:08 Opening connection to SIP provider
14:47:08 Test failed: Failed to process message; no retries allowed

We see the following in the sip2 server log:
2017-10-12 14:56:12 07 [001] [log] Initialized from Address 196.1.172.30:4544 
...
2017-10-12 14:56:13 37 [001] [log] IN 9900302.00AY1AZFCA5^M 
...
2017-10-12 14:56:13 54 [001] [log] OUT 98YYYNYN03001020171012 1456132.00AOALEPH|AMUniversity Libraries (ABC50)|BXYYYYYYYYYYYNNYNY|AN196.001.172.030|AFACS status.|AGACS status.|^M 
2017-10-12 14:56:13 54 [001] [log] Wrote 139 Bytes, Total 139 Bytes
2017-10-12 14:56:13 62 [001] [log] IN 97AZFEF5^M 
2017-10-12 14:56:13 62 [001] [log] OUT ^M 
2017-10-12 14:56:13 62 [001] [log] Wrote 0 Bytes, Total 139 Bytes 

Resolution

The self-check device (SC) is configured to expect a checksum to insure data integrity, but Aleph is not configured to send the checksum. (The usm50 tab_sip2.conf default is "error_correction = N".) This causes a checksum error on the SC side. It sends the 97 message asking that the previous message be retransmitted, but Aleph can’t resend the message with checksum turned off.

To correct this, modify tab_sip2.conf to enable checksum handing on the Aleph side. Change:
[HOST]
error_correction = N

to:
[HOST]
error_correction = S

(Note:  You should specify “S” rather than “Y”.)    Then restart the SIP2 server and retest.

• Article last edited: 16-Oct-2017