Sessions Lagging due to Bandwidth Limitations

Asset ID:	1-72-1944982.1
Update Date:	2017-03-28
Keywords:

Solution Type Problem Resolution Sure

Solution 1944982.1 : Sessions Lagging due to Bandwidth Limitations

Applies to:

Oracle Communications Performance Intelligence Center (PIC) Software - Version 4.1 and later
Information in this document applies to any platform.

Symptoms

Some specific sessions fed by the same xMF are running behind. The lag is decreasing during the night.

Cause

Bandwidth between the xMF and the related IXP servers is below recommended values.

Measure the bandwidth between xMF and IXP and compare it to the amount of traffic sent through the xMF routes to the IXP server:

Measure the rate of traffic sent from the xMF to the IXP by adding the amount of MB sent by each route to the concerned IXP.
Measure the bandwidth between xMF and IXP using the SCP command. Transfer a quite voluminous file (bigger than 20MB) from the PMF to the IXP and check the transfer speed. As root:

# scp /etc/selinux/targeted/modules/previous/base.linked root@10.34.10.2:/tmp/
root@10.34.10.2's password:
base.linked 100% 19MB 1.9MB/s 00:10

The bandwidth (transfer speed) is given by the output result of the SCP command (in this example 1.9MB/s).

Bandwidth should be at least twice bigger than the expected total of sent traffic in order to have comfortable margin in case of traffic increases.

Solution

Increase the bandwidth between impacted servers. This action needs to be synchronized between support engineers and customer because a lot of equipments, under customer responsibility or Oracle responsibility, can intervene during this step:

On Oracle support side:

Check the configuration of network interfaces of the concerned xMFs and IXPs. Especially verify the Speed value and the Duplex mode. ethtool command can be used to achieve the stated checks. As root:
# ethtool eth01
Settings for eth01:
  Supported ports: [ FIBRE ]
  Supported link modes: 1000baseT/Full
  2500baseX/Full
  Supports auto-negotiation: Yes
  Advertised link modes: 1000baseT/Full
  2500baseX/Full
  Advertised auto-negotiation: No
  Speed: 1000Mb/s
  Duplex: Full
  Port: FIBRE
  PHYAD: 2
  Transceiver: internal
  Auto-negotiation: on
  Supports Wake-on: g
  Wake-on: g
  Link detected: yes
Check the ORACLE switches configuration and ensure that they correspond to the network interfaces configuration of the concerned IXP and xMF.

On customer side:

1. Check the network switches configuration and ensure that they correspond to the network interfaces configuration of the concerned servers (xMF & IXP) and the related Oracle switches.

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