How to see what your users see

Submitted by fredrik.nyman on Mon, 02/11/2019 - 10:21

Live broadcast TV is one of the most popular services in fibre networks. You can get high quality pictures because there is enough bandwidth to send video uncompressed. But the nature of broadcast media is that it is very sensitive to packet loss or jitter. There is no retransmission of packets because it is live – you can’t hold the stream to get a lost packet back. And buffering is also a problem, keeping too large a video buffer to mitigate jitter will make your neighbour scream “GOAL!” long before you see it on your own screen – so it’s not really 100% “live” anymore.

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Multicast based TV is also difficult to troubleshoot. It takes so little – a single packet lost – for the problem to be immediately visible to the viewer as picture freeze or pixilation. Plus, as most viewers watch TV, its during evening time peak hours that the most problems are reported and that’s when you that work with the network are at home as well. On top of that, to actually track down where packets are getting lost can be a very tedious task. You will most likely have to go from port to port, from switch to switch to figure out where the packet loss happens in the network. If the problem is only seen during peak viewing hours in the evening and if you only have one or a few probes to work with, finding the root cause can take days to track down. Meanwhile your users are suffering and complaining and their resentment towards your service and network grows out of the frustration of not having the perfect picture they expect.

Enter real-time protocol monitoring of MPEG over multicast. This powerful feature available in Waystream MS and ASR series of switches uses the network processor in these systems to monitor the multicast traffic passing through. Going deep into the TV-streams the feature allows the switch to detect packet loss and jitter (variation in delay) which are typical issues that gives a poor TV experience. Since the feature can monitor multiple channels at the same time, and since each error can be individually tracked per channel it gives you a powerful insight into the quality of the multicast TV running through the switches.

This built in multicast probe turns every switch in your network into a monitoring station. Some customers use this to proactively monitor the network by collecting data and graphing it. Others mainly use it as a troubleshooting tool, activate when there is a problem in order to quickly pinpoint where in the network the cause is.

Having this function in the switches complements similar features in many setopboxes. When combined you have a powerful tool built into your network that lets you see what your users sees.

Blog posts

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Submitted by fredrik.nyman on Mon, 04/01/2019 - 09:08

The distributed nature of a fiber to the home network means that you will have equipment spread out and you might not always do the on-site installation yourself. If every switch has to pass your desk for pre-configuration port before getting deployed into the field you will need to deal with the logistics of getting the units from your warehouse via your desk, packing and unpacking, and clearly marking them so that the right unit goes into the right location.

SDN and NFV in FTTH

Submitted by fredrik.nyman on Thu, 03/21/2019 - 09:51

I love acronyms. You got three of them in the title of this post.

In recent years we got Software Defined Networking (SDN) and Network Function Virtualization (NFV). Many of the large telcos have invested millions into research of these subjects and are pushing the industry in this direction. Telefonica has expressed high ambitions to move to a completely SDN/NFV enabled network in record time. All the big ones are involved.

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Submitted by fredrik.nyman on Fri, 03/15/2019 - 09:50

Building fibre to the home networks are different from any traditional enterprise or telecommunications network. One of the main differences is the time it takes to complete the network. You make a plan, design a an architecture with VLANs and redundancy and imagine how this will scale as the number of connected customers increase. But then the years go by, because building a fibre network to connect every home in the community can take decades.

Save the planet - work from home

Submitted by fredrik.nyman on Thu, 03/07/2019 - 10:30

In my last post i revealed how dirty a fiber network can be depending on the source of electricity powering the network. I showed how a typcial 24-port access switch might contribute anything between 23kg to 485kg of carbon dioxide per year to the atmosphere depending on the electricity mix and how that can be reduced with lowpower optical modules.

How do you troubleshoot IoT devices?

Submitted by fredrik.nyman on Fri, 02/15/2019 - 13:00

Continuing on the subject of troubleshooting the network. Troubleshooting MPEG video has the benefit of a user that can tell you if it doesn't work and you can simply ask that user if the problem persists once you have fixed it. But what if there isn't any obvious way to determine if things are working, for example is that trashcan really signalling that its' full or does the temperature device really update the building climate control properly?

How to see what your users see

Submitted by fredrik.nyman on Mon, 02/11/2019 - 10:21

Live broadcast TV is one of the most popular services in fibre networks. You can get high quality pictures because there is enough bandwidth to send video uncompressed. But the nature of broadcast media is that it is very sensitive to packet loss or jitter. There is no retransmission of packets because it is live – you can’t hold the stream to get a lost packet back.