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Greetings,<BR>
<BR>
I have a situation that seems like a condition not addressed by the 1998 AX.25 Link Access Protocol Standard V2.2 nor programmed into jnos. Consider the following exchange extracted from a packet trace:<BR>
<BR>
Wed Feb 15 19:31:02 2006 - vhf sent: > fourth request<BR>
AX25: K8RRA-15->N8YJT SABM(P)<BR>
<BR>
Wed Feb 15 19:31:42 2006 - vhf recv: ERR?> in frame<BR>
AX25: N8YJT->K8RRA-15 RR(P) NR=0<BR>
<BR>
[ANALYSIS: This RR(P) should not arrive - it implies an already open connection.<BR>
The two ends of the link are out-of-sync at this moment.<BR>
The cause may be that N8YJT did not receive the UA(F) frame sent 19:28:30 <BR>
to acknowledge the DISC from YJT at 19:28:30. The DISC frame at 19:32:29<BR>
seems to confirm the cause.]<BR>
<BR>
Wed Feb 15 19:32:23 2006 - vhf sent: > fifth request<BR>
AX25: K8RRA-15->N8YJT SABM(P)<BR>
<BR>
Wed Feb 15 19:32:29 2006 - vhf recv: > disconnect - connection= #3 finish<BR>
AX25: N8YJT->K8RRA-15 DISC(P)<BR>
<BR>
Wed Feb 15 19:32:29 2006 - vhf sent: ERR?> busy - connection= #3 terminated<BR>
AX25: K8RRA-15->N8YJT DM(F)<BR>
<BR>
It seems to me that the RR(P) frame needs to be treated as an "unexpected response error" in the Data-Link State Machine (appendix C4 paragraph C4.3. under Error Codes) standards and in jnos. It seems certain that jnos ignored the RR frame and continued with the SABM sequence. <BR>
<BR>
As a secondary thing, when the DISC frame arrived at 19:32:19, the respnse of UA seems correct rather than the DM. This is a lesser issue because both the UA and DM cause the same result...<BR>
<BR>
The workaround for this situation might be to wait until all timers have expired and both ends have reset prior to beginning a SABM sequence. <BR>
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73<BR>
de Skip k8rra k<BR>
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