EAGLE Alarm 0535 IP Connection Restricted On STP

Asset ID:	1-71-1970279.1
Update Date:	2017-02-15
Keywords:

Solution Type Technical Instruction Sure

Solution 1970279.1 : EAGLE Alarm 0535 IP Connection Restricted On STP

Applies to:

Oracle Communications EAGLE (Hardware) - Version EAGLE 3x.x and later
Tekelec

Goal

"IP connection Restricted" alarms observed on some Associations:

****14-12-31 18:12:55****
  1707.0535 * IP7CONN assoc04 IP Connection Restricted
  ****14-12-31 18:14:23****
  1799.0535 * IP7CONN assoc03 IP Connection Restricted
  ****14-12-31 18:14:48****
  1829.0535 * IP7CONN assoc01 IP Connection Restricted
  ****14-12-31 18:16:28****
  1932.0535 * IP7CONN assoc07 IP Connection Restricted

What is cause of this issue? Does it have an impact?

Solution

Step-1:

First make sure that if the association is multihomed; it has alternate local and remote host defined in rtrv-assoc

rtrv-assoc:aname=assoc08
  ANAME assoc08
  LOC 1303 IPLNK PORT A,B LINK A2
  ADAPTER M3UA VER M3UA RFC
  LHOST stpa1303a
  ALHOST stpa1303b
  RHOST assoc101
  ARHOST ---
  LPORT 2905 RPORT 1324
  ISTRMS 2 OSTRMS 2 BUFSIZE 200
  RMODE LIN RMIN 120 RMAX 800
  RTIMES 5 CWMIN 3000 UAPS 10
  OPEN YES ALW NO RTXTHR 10
  RHOSTVAL RELAXED

  LSN
xxxxx

In rtrv-assoc output, the LHOST and ALHOST are defined but for remote side; only RHOST is defined. No ARHOST is defined.

From Customer Documentation >> Unsolicited Alarm and Info Messages Page 276:

  0535 - IP Connection Restricted
  Although an IP connection has failed, some traffic is still flowing through an alternate SIGTRAN
  (SS7-over-IP) link.
  The following two scenarios exist:
  • The SCTP association is established and the SCTP far-end is multi-homed and the Eagle determines
  one or more far-end IP destinations for the association are unreachable.
  • The SCTP association is established and the SCTP far-end is uni-homed and the SCTP near_end
  has an LHOST and an ALHOST configured.

So; either remove the ALHOST or also add ARHOST in association to clear this UIM.
Please note that this is not causing any sort of traffic failure on this association.

Step 2:

Once multi-homing is configured properly focus on fine tuning the Association Parameters.

Associations for which alarm is being observed have a higher Maximum Round Trip Time which is more than RTOmin.
Associations for which alarm is not observed hava a Maximum Round Trip Time which is still lower than RTOmin.
As the weighted average times are well within the RTO limits; so need to change the values.
Changing the RTOmin value solves the intermittent alarm of IP connection restricted.

Association not showing alarm:

PASS:loc=1301:CMD="ASSOCRTT assoc07"
      Retransmission Mode              : LIN
      Minimum RTO                      : 120
      Maximum RTO                      : 800

      Minimum round-trip time          : 2
      Maximum round-trip time          : 115
      Weighted Average round-trip time : 9
      Last recorded round-trip time    : 9

Problematic Association:

****14-12-31 18:14:48****
1829.0535 * IP7CONN assoc01         IP Connection Restricted

      Retransmission Mode              : LIN
      Minimum RTO                      : 120
      Maximum RTO                      : 800

      Minimum round-trip time          : 1
      Maximum round-trip time          : 204
      Weighted Average round-trip time : 39
      Last recorded round-trip time    : 53

So increase RTOmin Value using chg-assoc command to cate the maximum RTO time being observed here.

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