Monday, January 29, 2018

What Makes a PON Power Meter




A fiber optic power meter can be configured to receive the wavelengths used in a PON network, but testing those wavelengths indidivually from either direction poses its share of problems in a dense access network. The efficiency of the technician in this environment is paramount, and I would like to tell you about a power meter that corners the market for PON applications.

Years ago EXFO released its first PON power meter, the PPM-350 which was more than just a PON wavelength calibrated instrument. The PPM-350 series featured an exclusive, patented pass-through desgin that allows for concurrent upstream/downstream measurement.


The pass-through design allows for a single test anywhere in the optical distribution network, and it displays all signals simultaneously. You can add an option for downstream RF video at 1550nm if the network requires it.

An additional benefit of the pass-through design is that the customer's link under test will remain up while the tests are performed. Depending on which wavelength is experiencing difficulty, they would maintain use of service to some capacity instead of being entirely removed from the network.

Combine the efficiency of performing a single test with the pass-through capability with the advanced reporting of the PPM-350 series, and you truly realize the time-saving potential of this device. The original PPM-350 features a job editor that allows you to pre-configure upcoming jobs in the instrument's memory. Once on site, simply select the appropriate job ID, ONT number and location for super fast data collection. Reports are quickly generated from the device or software on a PC.

As time and technology march on, new PON technologies already being deployed run at different wavelengths than B/E/GPON. If you're considering implementing a next generation PON, NG-PON2 has some distinct advantages for layering on an existing PON standard. While there are so many elements to consider depending on the next-gen technology you select, there is a power meter already able to meet those needs.

The new PPM-350D power meter from EXFO combines all of the features from the previous 350C series, plus it offers the world's first PON-aware™ enabled power meter. That means the PPM-350D automatically detects which PON is in use on the link and returns the reading based on automatically adjusted pass/fail thresholds. So whether testing 1Gbps or 10Gbps service, this device can eliminate costly guesswork and time that would be wasted calibrating the instrument.

The good news is, no matter what technology comes next, the current infrastructure designs will be used. The test methods have a familiar, efficient face with EXFO as they continue to stay ahead of the power meter pack.

You can find information on the PPM-350D power meters in the Fiber Loss Testing Section of our website, and you can contact our sales team with any questions.


Monday, December 18, 2017

A Season for Giving Back

The holidays are a good time to reflect on what you’ve accomplished, how you’ve impacted others, and where you can make a difference. At Comstar Supply, we took this time to recognize those that are less fortunate then us and give back to our community.
Left to Right: Chad, Mary (back), Lachelle (front), Rich, Bruce (back), and Andy helped deliver donated food to the local food pantry.

“Volunteering and having an impact on our local community is firmly rooted in our company culture,” said Comstar Supply President Chad Punchard. “For more than 20 years, giving back is something we’ve prided ourselves on, and the efforts of our employees this holiday season exceeded my expectations.”


In the month of November, the entire company participated in a team-building event created around the idea of giving back. The first phase of the event split the company into 3 teams of about 12 people where employees participated in a food drive. This effort resulted in an initial donation of more than 1,800 non-perishable food and household items.

Phase two of the team-building exercise included team competitions in a number of “Price Is Right” themed contest ranging from blackjack to plinko. Each team earned extra points for phase 3 – A “Supermarket Sweep” themed contest to spend a Comstar-matched donation of $500 and buy as many non-perishable food and household items as they could.



“As you can image, coordinated groups of 12 people running through local grocery stores provided some high comedy and funny looks from shoppers, but the mission of the teams really stood out,” said Lachelle Wilfong, HR Director for Comstar. “In total, we gathered more than 3,300 items before the Thanksgiving holiday, which equated to about 2 truckloads we unloaded at the Daily Bread Food Pantry, our local food bank.”

In addition, the company also participated in an Angel Tag - Give a Gift program. Employees were encouraged to donate toys this holiday season that were donated to the local Salvation Army for underprivileged children this week.



Lachelle added, “I think we all had fun playing the games and participating in the team building event, but enjoyed seeing the faces of those we impacted with our donations even more. I'm so proud of what we accomplish every day here at Comstar, and even more so when we give back to our community.”

Monday, November 20, 2017

Service Assured: No Broadbandits Here!

Providing Ethernet services is usually never easy, and configuring them can be a wild west shootout. Sometimes services don't always burn-in as intended. On other occasions, factory configurations become field modifications. Even if everything goes perfectly at installation, problems can occur when services are upgraded. Pushing the gas pedal on a 10G link to 40G and beyond may bring to light fiber characterization issues you weren't prepared to deal with. Back reflectance values in the network that were once tolerable, are now stealing your valuable packets.

Well, I have good news for you. New devices and applications make it easier to not only verify the speeds of an Ethernet link and check for packet stability, you can maintain SLAs with greater efficiency and visibility.

Let's take a look at three products that further simplify service assurance and verification testing.


The EX1 from EXFO is an elegantly simple device that should become to the telecom service technician what the Non-Contact Voltage Tester is to the electrician. Use the EX1 paired with an Android device to qualify broadband connections delivered to both resident and business Ethernet customers. This platform will soon be available for iOS as well, and it allows service providers to quickly validate delivery of full line rate Gigabit Ethernet speeds to their subscribers.

The on-board power of the EX1 is a field-programmable gate array (FPGA) circuit that provides an open-platform. This is a critical feature that will help the EX1 keep pace and provide reliable results for years to come. This tester also features a partnership with the industry-leading Speedtest by Ookla, which provides a simple, easy-to-read interface you can share with your customers.

The EX1 is capable of hosting EXFO's Active Verifier Virtual Network Functions (VNF) to deliver a complete level 3 to level 7 service assurance solution. When activated, the Verifier VNF can offer a suite of more than 140 performance tests for the EX1 including Y.1564, IP connectivity, VoIP qualification, internet experience and more.

Furthermore, the EX1 can be left on site for temporary troubleshooting, or permanently deployed as a fixed performance endpoint that continuously reports on network and service performance. The cost of leaving the device behind might certainly be less than rolling a truck with a service technician qualified to troubleshoot Ethernet links.


The next product fits a wider range of applications. Are you transitioning your network from legacy technologies over to Ethernet? We know a device that can replace up to 8 sleepy, older test sets with a new one capable of verifying up to 10G Ethernet. Utilities, municipalities, E911, data centers and service providers alike can benefit from the power packed into Greenlee's DataScout® 10G.

The 10G can test multiple services simultaneously including Ethernet, DS0 (TIMS), DS1, DS3, T1, DDS and more. There is a separate unit capable of DDS, but all other services can reign on one device with easily navigated menus on a 7 inch color touchscreen. The 10G is fast, and it powers up 3 times faster than competitive devices.

It is a tablet-based design that comes loaded with standard applications including a web browser, email, document viewer and more. You can control the DataScout® 10G remotely via bluetooth, or a standard web browser. This instrument is also proudly designed, manufactured and supported in the United States.

Finally, I would like to discuss a powerful application that can pay dividends for those who take advantage.

Technicians who maintain Service Level Agreements (SLAs) undergo significant amounts of training to understand ITU-U Y.1564 and RFC 6349. Not only for commissioning services, but monitoring key performance indicators (KPIs) is a significant challenge in our industry. In a highly volatile world of mergers and acquisitions, lit service providers must juggle deployment standards when new networks come online. If the goal of a merger is continued sales growth, how can you ensure that your new technicians are fully trained in periods of explosive growth? Meet iSAM.


As a leader in test and verification equipment, EXFO is no stranger to designing simple GUIs and platforms that put time back into a technician's day. EXFO's iOLM interface revolutionized how OTDR traces are performed, and many competitors today offer link mapping integration. iSAM is another innovation for Ethernet Service Activation, and is available for multiple EXFO platforms.

Designed for end-to-end validation of layer-2/-3 and TCP layer-4 services, iSAM handles everything from GigE to 100 GigE in a simple 3-step process. That simplified process translates to a reduced test time of up to 10x, thus increasing the number of tests that can be done in a day's work. With service turn-ups and assurance testing that takes less time, service providers can take advantage of the greater revenues resulting from better service.

So don't forget, old singlemode fiber is out there. 100 GbE is going to find your macrobends and your high back reflectance that may not effect 10 Gig. Or are there issues with the networking equipment causing jitter? These problems are out there today to rob your network of valuable packets and performance. Find those hidden Broadbandits before they cause damage to your valuable services.


Wednesday, November 1, 2017

The #2 Pencil of Fiber Testing

Don't Take Fiber Launch Boxes For Granted

How often were we reminded to use only a #2 pencil when taking a standardized test? How ridiculous did it seem that instructors thought we would use anything but a #2 pencil? Not only would we bring our #2 pencils, but we would make sure we had at least one fully sharpened backup. Inevitably, the first circle would spell doom for a weak tip no matter how well you thought it was sharpened.

Many of us can still recite the litany of requirements for test taking. We've heard them so often, they're etched into our minds and our culture.



When I relate this to fiber testing, one question lingers in my mind. Where is our instructor to remind us the importance of fiber launch boxes? I am shocked by the stories I hear from the field where OTDR tests are performed with faulty or even without launch boxes. Two incidents I recently heard dealing with separate service providers encouraged me to write this blog.

The first situation caused quite a lot of havoc with a supplier who provided passive splitter cabinets for a large FTTP deployment. Tests were showing significant loss through splitter ports, but the results were inconsistent. Some ports tested fine while others were failing. Those results would not automatically cause you to question the launch cable you're testing with, but the end result proved that the launch cable used was faulty. Before the launch cable was called into question, additional replacement cabinets were shipped, many hours of resources utilized, and construction was delayed.

Another similar situation occurred with fiber access terminals on a FTTP project. Some hardened ports on the terminals were failing, but not every port or every terminal. It is reasonable to assume the product may be at fault due to the inconsistency of the tests. How could a launch cable be the issue when it is passing through the other ports? The connectors may still pass, but they may pass with higher insertion loss levels or back reflectance than they actually have. In this particular case, the launch cable used did not have the appropriate connector to mate with the hardened ports, therefore additional loss occurred due to air gaps.

These scenarios deal with inspecting and cleaning connectors as well as using the proper connections to ensure the best results. Let's take a look at the role of launch cables as well as highlight suppliers that make the extra effort to provide a superior launch box.

The launch cable (aka pulse suppressor) covers what is known as the dead zone of an Optical Time Domain Reflectometer (OTDR). Due to the high power pulse coming from the OTDR, the initial pulse plus a few meters is the length of cable where events are not seen--hence the dead zone. Using a launch cable and a receive cable allows you to see the first and last connections of the fiber under test. The image below shows an OTDR trace with launch and receive cables attached.



How long does a launch cable need to be? That is determined by the maximum pulse width of the OTDR, and the cable should be longer than the pulse dead zone used for the tests. For instance, a 1 μs pulse is approximately 100 m long. Therefore selecting a 150 m - 300 m pulse suppressor box or launch test cable would be appropriate.

Several OTDR manufacturers claim to have pulsewidths today as small as 3 nanoseconds, which is great for added visibility in shorter access network links. First of all, buyer beware if you source an OTDR in search of the short pulsewidth. Tests have shown that several equipment manufacturers are closer to 5ns when the gear is on the lowest setting. Second, it becomes even more critical to use a long launch cable to ensure you can accurately test the leading connector in the short run.

Nothing more than a jumper in a rugged enclosure, fiber test cords are made by a multitude of suppliers with a wide array of optical fiber types inside. Simply saying you would like a "Singlemode launch cable with an SC-APC connector" does not mean that you'll get a G.652.D singlemode OS2 fiber in the box. The popular mini launch coils might feature a bend-insensitive G.657.A1 singlemode fiber, while your fiber under test is G.652.x.

The case of mixed singlemode types is very common, but it is important to be aware of the TIA-526-14B standard (IEC 61280-4-1). This standard dictates that if you cannot validate the fiber characteristics between the test cords and fiber under test are the same, you must do a bi-directional fiber test. Optical Loss Test Sets accomplish this task, but it is less common for OTDR testing.

In order to test to this standard properly with an OTDR, the test cords may not move. It requires 3 test cables: a launch fiber, loopback fiber and a receive fiber. Bi-directional tests average the absolute values in each direction over a single strand or fiber pair.  This approach simplifies the test because the OTDR operator stays at one end of the fiber under test, and only moves the OTDR from the launch cable to the receive fiber.

Based on these requirements, it is only logical to require a high quality test cord that is rugged and reliable. It's important to make sure the test cords are supplied with the highest quality factory polished and terminated connectors. Those connections will be used more than any jumper in the network, so let's make sure they have low insertion loss, return loss and are prepared for the abuse.

Over the years, Fiber Plus International became a name that our customers associated with high quality launch cables. Service providers offering the highest speed and bandwidth service recognized the consistently low reflectance and insertion loss values. Fiber Plus' Dead Zone Eliminators are available in traditional pelican cases as well as small launch coils. Fiber Plus also manufactures bare fiber adapters that make testing fiber reels and non-terminated fiber a snap.

Another supplier of distinction for test cords is Megladon. Their patented Hardened Lens Contact (HLC) process changes the physical properties of the glass at the connector endface. HLC creates a higher performance connector endface as well as a scratch resistant surface that significantly increases the number of insertions per connector. Every assembly that Megladon manufactures features the HLC technology, so you can insist on the highest quality jumpers and test cords.

No matter how durable the endface of your test cords and jumpers may be, you still need to inspect and clean them. Comstar Supply carries a wide array of hybrid and dry cleaning solutions to keep your test cables performing consistently and reliably.

So the next time you break out the OTDR or loss test set, don't forget you're #2 pencil! Make sure they are sharpened (clean), and make sure you have enough of them to complete your test without having to leave your desk.

Monday, October 2, 2017

What's New With ADSS?

While All Dielectric Self-Supporting (ADSS) Fiber Optic Cable saw a boon from 2008-2011, we still come across customers who may not be familiar with this type of cable. It became a hot product as an alternative to traditional lashed aerial cable in the telco market. Prior to that, it was primarily used by utilities in their own SCADA networks, but long-haul telco providers found value in the reduced make-ready that resulted by placing cable in the less congested secondary power space.

What brought ADSS back down to earth for telcos were a couple of factors: the cost of the cable and its availability. Nearly every ADSS cable has to be pre-engineered per National Electrical Safety Code (NESC) specifications, which created additional lead time and made it difficult for distributors to stock because there wasn't a single product available to fit all applications. Furthermore, the cost of the aramid (Kevlar) in the cable increases your material costs on the project, especially for longer span and higher fiber count applications. In addition to these factors, contractors needed to train and wear special protective equipment to access the power space for installations and maintenance.

I would like to make some additional clarifications on ADSS, since I have heard some confusion from customers on what the product actually is. As the name implies, "All Dielectric" means that there are no conductive elements in the cable. This is the key to placing within the power space, because the NESC requirements mandate you use a system that is non-conductive. Traditional self-supporting fiber optic or copper cables with a steel messenger or copper conductors do not qualify as all dielectric, so "Figure 8" cables and duct are out.

So how does the cable self-support without an integrated messenger? There are one of two ways:
Fiberglass Reinforced Polymer (FRP) strength members, or Aramid (Kevlar). FRPs are common with service drop or flat drop type cables with lower fiber counts. The Aramid designs are most typically used with long-haul routes, and they offer higher fiber counts. These designs allow for dead end and tangent attachments to be applied directly to the cable sheath. Traditional fiber optic cable designs do not allow for attachments directly to the jacket.

Especially for Aramid cable types, the dielectric materials must be designed to support the cable up to it's Maximum Rated Cable Load (MRCL) and Installation Tension. Fiber counts and cable diameter also factor into application criteria used to calculate a cable design. When you are looking for price and availability on aramid ADSS cable, be prepared to provide the key information required to produce a quote. That information includes:

  • Fiber Count and Type
  • Maximum Span Distance
  • Weather Loading (NESC Light, Medium, Heavy or other)
  • Line Voltage (kV) if transmission lines are used
  • Installation sag (1.5% typical)


There are still applications for ADSS in telecom networks today, and even more is still being deployed. For some routes, ADSS is your best option. There have been some new products to the market since the boon several years ago, and I would like to highlight those here.

Hubbell Power Systems launched their ADSS hardware line that includes traditional formed wire dead ends, but they also have a couple of products aimed at reducing material costs and installation time.

Hubbell's new ADSS suspension clamps only consist of 2 part numbers that cover spans up to 600 feet with cable diameters ranging from 0.394" to 0.787". Instead of managing multiple SKUs for a build with multiple fiber counts for backbone and laterals, you can count on 2 part numbers at the most for your tangents. This simple design allows for installation in just a few seconds, and it can be bolted or banded to the pole. If a loose tangent is required, you can even mount this clamp with a J-Hook.

The other innovative product that Hubbell launched was their ADSS Wedge Deadend. Installation takes seconds with no special tools required, and these deadends will support spans up to 325 feet. The flexible bail provides extra protection to the cable against Aeolian vibrations, which would require you to purchase additional vibration dampers if using traditional formed wire grips. These are also safe for installations up to 11kV.

In dealing with service cables we often get requests for flat drop cable with more than 12 fibers. The only options were to run multiple 12 count drops, or lash a traditional cable. With the arrival of PPC Broadband's Miniflex ADSS cable, we can offer a round cable with strength members to accomplish this task while still using J-Hook attachments. In a 7mm jacket, PPC can squeeze up to 48 fibers in a dry package that is easy to strip and access. This product enables operators greater flexibility in their access networks to deploy higher fiber counts without the need for surveys, planning and remedial civil works, thereby facilitating rapid and cost effective aerial network deployment. As FTTH and cellular backhaul/fronthaul projects continue to rise in the United States, this cable is worth a look! You can download the data sheet on PPC Miniflex here.

For further information on ADSS and these new products, please contact your Comstar Supply sales representative today.

Monday, August 21, 2017

Damage in the Name of Prevention

Examining the Costs of Fiber Tracing Material

by Matt Brice
This article originally appeared in the Summer 2017 issue of Damage Prevention Professional magazine. It is being reprinted here with permission. You can read the original printing in the digital issue of the magazine: https://view.joomag.com/damage-prevention-professional-2017-q3/0055544001498760415?short
 Selecting armored fiber optic cable for direct burial or a tracer wire element to install with your next underground build might allow you to “check the box” that your plant can be found. However, are you creating an effective system to do so for the life of the network? Today I ask network operators to reflect on how you specify and order materials based not just on capex, but some of the hidden operating costs with toning options on the market today.

I recently compiled one mile worth of connected cost data for the several types of toning options associated with fiber builds. These figures only include materials, and they do not include any labor estimates. We will look at the implications of using cable armor versus a tracer wire element. While this article applies to telecom networks, it does include valuable cost comparisons for locating products used for all utilities.

Friday, July 21, 2017

Overriding Issues with a Fiber Overbuild

What to Know: Fiber Overbuilds

As original fiber routes are now coming due on their life expectancy, we've found out a lot about how cables age in their environments. That discussion alone could fill multiple blogs and whitepapers. The improvements in optical fiber design are pushing back the cabled fiber retirement age past 40 years. But, what if you need to bite the bullet and overbuild an existing route to maintain your QoS?

The cost of new excavation or boring can be detrimental to your balance sheets, so what can you offer them? Cable jetting in an override application can be a feather in  your cap, but you should proceed carefully before going down this route. Here are some things to consider.

Duct Depending

A thorough inspection of the quality of the existing pathway should be conducted. If the duct integrity is good, and it can hold pressure, you should have good results. A good pressure test alone may not guarantee success, however.

Going the Distance




Don't count on the claims of your cable blowing equipment to get you there. Due to the additional air chamber in your Y-Block, there is more potential for air to leak out of even the best system. The parachute style carrier used for overrides isn't as effective at sealing the air in front of the cable, which will slow you down as well. Not to mention the added friction of the cable running against what's inside the duct, try not to be overzealous with distance claims.

If your runs are 1000 - 2000 feet, and you have good duct integrity, you should see success. The equipment manufacturers will still make no guarantee as every job is different.


How did the first cable go in?

If you know the existing cable was blown in originally over longer spans, you could be up for a significant override challenge. Since cable blowers push the cable through a pressurized duct, a cable may not lay flat inside the duct towards the end of the run. Picture a wet noodle with peaks and valleys. If a cable was pulled in, it should be laying flat. Ultimately you would want a cable to be laying flat at the bottom for you, but that doesn't always work out.


Microduct First

You can pressurize a microduct and send it through your existing pathway if the room allows for it. We have run simulations of this at our Collegeville facility for customers interested in trying this method. This will also insure that the cable could easily be reclaimed and the pathway re-used if necessary.

Go Smaller

New microduct cable technologies are pushing the envelope on how many optical fibers you can cram into a space. Do not expect this trend to change. The most recent development from AFL is their LM200-Series OSP Microcore cable that is the smallest thing yet to be Telcordia GR-20 compliant. That being said, it's not the product you'd want to lead with in a greenfield. But this is your answer if you originally wanted to go with a 432 fiber count, and you could only get 96 strand using traditional microduct cable. Fair warning: your splicers may throw objects at you for specifying 72f per tube cables.

Get a Guru

Comstar, as well as our suppliers, have experience assisting with overrides in the past. We all want your job to run smoothly, and we are glad when we can champion another success story. We would certainly like to offer our advice and expertise along the way.

The costs for override installations certainly justify themselves, but it may not work for every situation. If you've already done an override, we would love to hear about the pitfalls and successes of the project. If you're considering an override, please don't hesitate to contact us to see how we might be of service to you or your contractor.