High Retransmissions on One Association

Asset ID:	1-72-2145612.1
Update Date:	2016-06-08
Keywords:

Solution Type Problem Resolution Sure

Solution 2145612.1 : High Retransmissions on One Association

Applies to:

Oracle Communications EAGLE (Software) - Version EAGLE 3x.x and later
Information in this document applies to any platform.

Symptoms

The customer is experiencing a high level of re-transmission on one association

Cause

There is an equipment in-between which is blocking some packets

The RTT is good and yet there are regular received Duplicate TSNs and GAPS blocks.

RTO between RMIN and RMAX inclusive = 0
  RTT greater than RMAX = 0

Retransmission Mode : LIN
  Minimum RTO : 200
  Maximum RTO : 800

  Normal Traffic Round-Trip Times

  Minimum round-trip time : 3
  Maximum round-trip time : 53
  Weighted Average round-trip time : 5
  Last recorded round-trip time : 5

We can also see in the logs some IP connection failures from time to time :

> rept-stat-slk:loc=2107:port=A2:l2stats=both

eaglestp 16-05-26 17:34:36 HST EAGLE5 45.0.0-64.70.31
  SLK      LSN       CLLI   PST   SST   AST
  2107,A2 hlrsig    eagle IS-NR Avail -----
  ALARM STATUS = No Alarms.
  UNAVAIL REASON = --

  Service Event Timestamp
  In Service            16-03-26 05:22:33.630
  IP Connection failure 16-03-29 00:28:53.525
  In Service            16-03-29 00:29:03.310
  IP Connection failure 16-04-04 00:57:15.160
  In Service            16-04-04 00:58:22.430
  IP Connection failure 16-05-20 01:55:45.320
  In Service            16-05-20 01:55:50.795
  IP Connection failure 16-05-26 09:16:08.560
  In Service            16-05-26 09:16:15.045

Solution

To troubleshoot the IP network and identify the responsible equipment which is having difficulties to handle all packets.

Attachments

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