Blog :: Network Operations

Application Performance Monitoring: Out of Order Packets

Monitoring out of order packets has just gotten easier.  In the past, it has been a challenge to setup specialized applications and tests to identify if poor application performance is being caused by out of order packets.

Out of order packet delivery is when when the delivery of data packets on a computer network is different from the order in which they were sent.  Since applications have a relatively small buffer for keeping track of packet ordering, when packets  continue to arrive out of order the TCP network protocol will have the packets retransmitted as they’re considered to be dropped.  The impact of out of order packets on critical applications, such as VoIP,  video and RTP, is a serious one because re-transmitting a packet due to packets arriving out of order has just as much impact on  application performance as packet loss.  Two common reasons that cause packet reordering to occur are multi-path networks and parallel processing paths within network equipment.

How to monitor Out of Order Packets

The nBox now exports IPFIX out of order packet information so you can have an eye on the network at all times.  When you export out of order packet delivery information to our network monitoring software you can store the data historically to create packet out of order baselines and then setup alerts thresholds for when the amount of out of order packets become too high.

Out of order packets by application

Even though the TCP network protocol provides guaranteed data delivery, even with packet loss and packets arriving out of order, your critical applications will still suffer from a loss of performance.  With the combination of an nBox and our network monitoring software you can take a proactive approach to network monitoring. If you’re looking for a guide on how to configure an nProbe IPFIX template, we have some great examples for you. How are you monitoring for out of order packets on your network?