Tag Archives: Bandwidth Hogs

Are Your Users Complaining? Pinpoint the Reason with OmniPeek

Try as you might, making users happy with network performance is a difficult task. Sometimes problems arise with applications and sometimes with the network itself. Either way, it is your job to make the end user experience the best that it can be.

Luckily, if you are using OmniPeek, problems of any type, whether application or network, or common or rare, can be easily remedied. Let’s take a look at some common user experience issues and how OmniPeek can help to identify the root cause and guide you towards a permanent solution.

Network Downtime
Fortunately unplanned network downtime is a pretty rare occurrence nowadays, but if it does occur the response must be instantaneous. With OmniPeek you can immediately assess the scope of the outage, from a few specific users to an entire subnet. If distributed, 24×7 analysis is in place, you can rewind the network to see exactly what was going on when the outage occurred, providing the best clues possible for determining the root cause, which in this case is probably equipment failure somewhere in the network path of the effected users.

Not Enough Bandwidth? Find the Hog
Bandwidth issues typically arise not because of a lack of bandwidth, but because a user or users are consuming an abnormally high amount of bandwidth. This is becoming more common with the wide availability of video streaming sources, particularly those that are not work related. The Compass dashboard in OmniPeek is an easy way to isolate bandwidth hogs, allowing you to identify not only the user but the type of traffic, providing the ammunition you need to ensure that network traffic is strictly business related.

VoIP Quality Issues
VoIP is the most commonly used real-time protocol on corporate networks. Given its real-time nature, it is extremely sensitive to network problems like too much latency, dropped packets, and jitter, much more so than “regular” network traffic. For real-time data to be useful, it must arrive in order, and within a few hundred milliseconds of being sent, otherwise it is no longer “real-time” and doesn’t fit into the overall conversational flow. Problems with real-time data will continue to grow as more corporate video is transmitted over IP networks, and as more wireless networks are used for the last 100m of data delivery (voice over Wi-Fi, or VoFi).

From a network perspective, VoIP, VoFi, or video over IP are just data on the network. In order to identify problems with real-time traffic, you first need to isolate the traffic, while still seeing it in the context of the overall network. To do this, you can use the Voice and Video dashboard in OmniPeek to see how real-time traffic is coexisting with the rest of the network. Then, the Calls and Media views will allow you to see a more detailed analysis of the packet-by-packet performance of the real-time flow, including detailed analytical metrics and a bounce diagram so you can pinpoint exactly where the problem is, and compare it with network activity to correlate real-time transport problems with overall network usage.

If you are experiencing another kind of reoccurring issue on your network, please leave us a comment and we’ll address best practices for remedying this issue.

Finding Bandwidth Hogs with the Compass Dashboard

Given the low cost and feature-rich networking equipment available today, it’s easy for bandwidth hogs to quietly operate in the background. Most corporate networks have plenty of bandwidth and lots of additional features, like traffic shaping, that significantly reduce the impact of bandwidth hogs. But they can certainly still be a problem, especially on slower, remote office networks, or wireless networks. And problems can be aggravated when “hogging events” occur, like video streaming of live, popular events, which bring even casual bandwidth hogs out of the closet.  With WildPackets Compass dashboard, you can easily navigate your way through the network to find exactly who the bandwidth hog(s) is and what he or she is doing to suck up so much bandwidth.

Identifying Spikes in Network Usage
The Compass dashboard in OmniPeek allows you to get an overall view of network utilization, whether by bits, bytes, or packets. It is an excellent starting point for identifying overall spikes in network usage, the first step in identifying the culprit behind the spike. As we can see in the following screen shot of the Compass dashboard, our overall network utilization on our wireless network has been erratic, with several spikes over the last hour or so. We can now use the interactive nature of the Compass dashboard to determine which user(s) are responsible for the various spikes in network activity.

Identifying Bandwidth Hogs
All that needs to be done is to isolate a spike, and the Compass dashboard will do the rest. Let’s choose the right-most spike in the above screen shot. Simply highlighting the area of the utilization graph directs the Compass dashboard to drill in on that area, focusing all of the Compass dashboard windows on only that period of time. This is illustrated in the following screen shot.

As you can see, not only have we focused on the utilization from just this time period, but the Top Protocols, Top Flows, and Top Nodes also reflect network utilization from just this time period. Looking first at Top Flows, we see that the conversation between and on port 80 is by far the largest flow, and we know that is a user on our network. Both the listed port and the Top Protocols pie chart confirm for us that this is web traffic, and the Top Nodes histogram clearly shows that the web activity was YouTube traffic. So, a single step using the Compass dashboard provides us will all the data we need to know exactly who our bandwidth hog is, and what they’re doing on the network.

Further Analysis
Knowing that there was a spike in network traffic, and who caused it, is certainly valuable information. But spikes happen all the time. As network engineers, what we’re most interested in is whether or not this event created any adverse effects on our network, and one of the best metrics to determine this is network latency. The Compass dashboard continuously analyzes for network latency, and displays this information over time. Simply change the parameter in the graph from “Mbits” to “Worst 2-Way Latency,” and we can now see the latency for the period of time when the spike took place, as illustrated below.

As the graph shows, our worst 2-way latency continues to increase while the YouTube download is occurring, reaching a maximum value of almost 13 seconds. In our book this is certainly an adverse effect!

The Compass dashboard is a flexible, extremely versatile view into overall network activity. With its rich set of network metrics and the ability to instantly drill into specific time periods, it guides you to exactly where network problems are occurring, in this case, identifying a potential bandwidth hog, along with the negative impacts this activity is having on the network.

3 Easy Ways to Prepare Your Network for the Olympics

With the Olympics approaching, most everyone in IT is having “World Cup Fever” flashbacks, and rightly so. When it comes to high-profile global events like the Olympics or the World Cup – we leave the biggest and best up to sports forums – internet traffic spikes, even if the end user is at work.

For example, on June 11, 2010 (a workday) Akamai reported that news site traffic started to climb steadily at 6 am ET and peaked six hours later, reaching nearly 12.1 million visitors per minute. Regardless of if people are at or away from the office, they are going to stream news from these sites to make sure they are up-to-speed with the latest events.

With the Olympic ceremonies this Friday, we wanted to provide some tips to prepare for more internet usage on your wireless and wired system to ensure that there will be no angry users whether they are trying to access work-centric applications or the synchronized swimming events.

Baseline Your Network
The only way to know whether you’ve improved your network performance is to start by knowing where it stands now in terms of network demands. Enterprises can get a sense of how their network normally acts by looking at internet connections, WLAN links, WLAN environments and the data center. A network analyzer can help organize this information into a report that can be used to not only solve issues that currently exist, but also to allow the organization to rewind the information back in time to validate performance and bandwidth utilization now versus previously, and predict future growth.

Prune and Clean WLAN Traffic
Remove unnecessary traffic. Devices like printers, support stacks and protocols not in use in the environment can be eliminated. Sometimes, protocols that help manage the network, like routing protocols and SNMP can be found needlessly hogging valuable bandwidth. It’s likely that there are no devices on your Wi-Fi network which require SNMP management, routing protocols, or similar network maintenance and management.

Additionally, you may be able to recover wireless bandwidth by disabling packets between nodes. Many BYOD-class devices use local multicasts to find network services. Blocking connections between Wi-Fi clients will prevent the retransmissions of those packets, thus saving valuable bandwidth.

Monitoring and Stomping Out Rogue Users
Since more and more people in your office probably have tablets and cell phones, they might be using these devices rather than office provided devices to stream Olympic events. Trying to maintain these rogue devices is a multi-tier approach, and you should have a practice in place to make sure you are aware of these devices and housing them in the right place so they don’t interfere with your network.

However, if you don’t have a plan in place like a special Wi-Fi SSID or WPA2, you will have to discover these rogue devices and make sure they do not pose a security threat to your system and are not being the bandwidth hog on your network. Again a network analyzer is good at finding these “unknown” wireless assets on your network.

If for some reason you are experiencing latency or something else, and the devices that you are monitoring on your computer are not the issue, check to see if it’s mobile users.

In next week’s article, we are going to cover the Olympics, but instead of looking at it from an office perspective, we’ll be looking at it from a live events perspective. How do you keep a network running smoothly at an event like the Olympics? We’ll discuss how WildPackets did just this with China Mobile during the 2008 Olympic Games. Stay tuned!