Basketball Systems and Network Monitoring Solutions

Two unrelated products addressing very different needs reminded me of the difference between products and solutions. The value I didn’t get from the one product helped me appreciate the value offered by the other. The first product was a basketball system, the other one a network monitoring solution. How so? Read on…

Last weekend I decided to assemble the new basketball system my wife and I had bought for our older son for his sixth birthday. The box in which the basketball system was packed was huge and included many parts. It also included numerous large bags with nuts, bolts, and some funny looking hardware pieces.

The installation guide looked more like a book than the mini-booklet I was expecting. It was filled with warnings and also tasked me, the buyer, with verifying that all ~150 parts were there before starting the assembly. Six hours (!) later, after having to re-assemble at least two parts because of misinterpreting the cryptic drawings in the booklet, I had the basketball system standing ready to be used. Actually, it was almost ready.

What I still needed to do was to fill the base with sand (per the vendor’s recommendation sand was safer than water). So now I had to find a funnel and a store that sells sand (OSH) and schlep heavy sand bags home, spending another hour pouring the sand in through the funnel. When it was all done, I had one clear thought in my mind – there must be a better way! I wanted to get a product that would work for me, not a product that would make me spend an entire day on reading, planning, assembling, re-assembling, shopping, and pouring.

This week, Net Optics announced an exciting new solution – the appTap. It’s a plug-and-play network monitoring solution designed for monitoring remote branch sites. One of the many compelling things about the appTap is that it’s a complete solution. It comes with everything that customers would need for monitoring remote sites. It includes a Tap that opens up network access, monitoring software, a PC board that runs the software, extra ports for additional monitoring solutions and USB ports for extensibility (e.g., adding storage capacity). Once connected, the appTap provides instant visibility and can be accessed from anywhere using a standard browser. In simple words – the appTap isn’t really a product, it’s a complete, immediately usable solution.

Solutions vs. products? I’d take solutions any day…

MTBF Reliability

When a new product is conceived and being designed do you ask who you are designing it for?

I do and as downtime becomes increasingly more focused on, for network products, instituting early requirements and long term reliability testing plans are becoming more important.  Using Mean Time Between Failure (MTBF) analysis is a way to approach reliability proactively early in the design process.  MTBF is data that calculates a prediction of field reliability on the parts that have been designed into the product.  While the data is useful it is only a tool and its intended use is to improve product design weaknesses before it reaches the market.  The way to validate this calculation is by instituting a long term reliability testing plan.

Are you being Customer First in your approach to product uptime?

Timestamping with Director xStream Pro

Timestamping packets has long been the key to accurate timing analysis when tuning network performance. Lately it has become especially critical in the financial sector due to the severe impact of even microseconds of latency on automated high-speed trading transactions. Since 2007, Net Optics has offered timestamping in its iTap access product line. Recently we brought the feature into our network controller line with the Director xStream Pro. The timestamp applied by Director xStream Pro uses a new, flexible, easy-to-use format that is explained in this post.

When timestamping is enabled in any of Director xStream Pro’s eight ProPorts (the top row of ports in the chassis), a 12-byte timestamp and a new CRC are appended to each packet that passes through the port. The timestamp records the precise time that the first bit of the packet arrived at the input port—this point is critical, as products that timestamp at the outgoing tool port lose accuracy due to variable delays through the device.

The timestamp format is diagrammed below.

As you can see, the first four bytes of the timestamp are a 32-bit binary value in seconds. The second four bytes are a 32-bit binary value representing tenths of microseconds; this field rolls over (returns to zero) when it reaches  0×98967F or 1 second. The final four bytes are reserved for use when higher-precision timestamping becomes available, making the timestamp format capable of supporting a resolution of 0.1 picoseconds.

Some examples of the timestamp are:

00 00 00 01   00 00 00 00   00 00 00 00 = 1 second

00 00 00 00   00 00 00 0a   00 00 00 00 = 1 microsecond

00 00 00 1b   00 96 ff   ff     00 00 00 00 = 27.9895935 seconds

The timestamp can easily be decoded by a protocol analyzer or other monitoring tool. A Wireshark capture of a timestamped packet is shown below.

Note that the packet’s original CRC is preserved. If a packet arrives with a bad CRC, the timestamp adds a good CRC on the end and forwards the packet to the monitoring tool. The tool can reference the original CRC to validate the packet. (When timestamping is NOT enabled, Director xStream Pro drops packets that arrive with bad CRCs.)

The timestamp is generated by a free-running 1 Mhz counter, providing microsecond  precision of the relative timing between packets arriving on any timestamping ProPorts in the chassis. Left by itself, the counter can drift slightly with time. To prevent drift, a pulse-per-second signal from an precision time source such as GPS can be applied to the BNC connector labeled GPS on the rear panel. Moreover, if multiple chassis are sync’d to the same time source, the timestamps will provide accurate relative timing for packets arriving at different chassis.

With the high-precision, input-port-based timestamping of Director xStream Pro, you no longer need to worry about adding a network controller switch between the traffic and your timing analysis tools. Director xStream Pro’s timestamps always provide your analyzer with precise timing of the packets on the wire, regardless of any delays introduced along the monitoring path.