Welcome to the Sunrise Telecom blog! Here, we hope to bring you useful information – testing techniques and technology tidbits which will be useful in your work. Cable, telecom, and mobile providers and technicians will all find valuable tips and concepts as time goes by.
The Sunrise Telecom Customer Solutions Team
July 12, 2011, by Scott Wolfe
How can I reduce my repeat CATV service calls?
Recently I was working with a CATV operator who has launched an aggressive drop certification program, whereby all personnel are required to disconnect the drop from the tap to measure ingress. The idea is that if they could reduce the amount of Noise coming from the house into the return path, they would improve the performance of all upstream technologies (VoIP, web surfing, online gaming, etc)
The tech would monitor any and all RF “Noise” emanating from the house when no signal was applied to the home network. Each time this certification is performed, a spectral signature is recorded on the meter using the return spectrum feature of the CM3 Series.
No noise should be present when proper steps are taken to use STB, Cable Modems, MTAs, and converters with high return loss specifications as well as to terminate open splitter ports, and minimize the number of un-used connections. Overall reducing the number of “Noise Antenna” available for problems to get into the network improves the experience for all customers.
The result of this aggressive noise mitigation program has been a drop in repeat service calls. The principle of the return path is just a great big funnel, the size of the funnel at the CMTS being the number of customers connected to a certain node in the field. If one thinks of the customer connection as an antenna, then you would surmise that any and all noise penetrating the return network can be amplified by the number of antenna available. If consistent practices in the field can eliminate or greatly reduce the chances of noise infiltrating the network, improvements in the network’s performance are a given.
This simple exercise is proven to show results, and when applied in each and every CATV system the results will show benefit of the work.
June 28, 2011, by Greg Potter
Laser Input Power Measurements & Your AT2500 Spectrum Analyzer
It doesn’t take much to convince a hub technician of the value of laser input power settings, and how critical they can be. Most lasers are specified with a “total power input” specification that lets you know what the optimum input level of the laser should be. Failing to set that input level correctly can cause many issues in the field. Low power inputs will cause your CCN to drop, creating noisy analog pictures out in the system and lowering your QAM MER readings at the same time. High input levels can cause laser clipping and unwanted distortions.
Most manufacturers will specify a total power input for the laser, and also provide a chart of channel loading versus individual channel levels so that you can calculate what your total input power might be. Calculating total input power based on individual power measurements using a few channels (perhaps the pilots) is not always accurate and not that simple. In many systems QAM signals are run a prescribed amount below the analog carriers. This is all well and good, but what if the 64 QAMs are running 8 dB down and the 256 QAMs are running 5 dB down from the analogs? What if the “pilot” levels change?
With your AT2500 you can eliminate the calculations, forget the need to worry about channel loading, and just take a simple power measurement over the entire bandwidth. Here is how to do it:
- Go to the Digital Channel Power measurement on your AT2500.
- Calculate your total bandwidth by subtracting your lowest forward frequency from your highest forward frequency. For example, if you have a 1 GHz system, subtract Bandwidth = 1000 Mhz-50 MHz = 950 MHz.
- Press F1 (Bandwidth) and set the DCP measurement bandwidth to 950 MHz.
- Calculate your center frequency. CF = BW/2 = 950/2 = 450 MHz.
- Press the FREQ button and set the center frequency to 450 MHz.
- Press the F6 Measure button; the instrument will calculate the total power over that entire 950 MHz bandwidth.
Utilizing the DCP measurement to determine total laser input power is the simplest and the most accurate method you have. Other methods involving individual pilot measurements and subsequent calculations only open up avenues where errors can be made. So break out that AT2500 and get checking those laser inputs.
Just a couple of pointers for beginners:
- Don’t forget to allow for the test point loss of the laser test point when you make your level adjustment or you will be experiencing laser clipping of the nTH degree!!
- If you’re in a system where channel lineups still change when you switch on your EAS system, make sure you check the laser inputs when the EAS is running as well.
Happy testing folks ☺
June 21, 2011, by Mark Milliman
The Changing Face of the Field Technician, Part II
Reduced training and a diverse set of field operations tools would not achieve the goals of operations management. Fortunately, attentive field test equipment vendors recognized these trends and responded to the challenge of the changing field workforce. Increasingly field operations vendors realized that carriers were streamlining their processes and striving for uniformity. The introduction of integrated test platforms was not just the natural evolution of test systems, but a whole new way to improve customer service and realize the goal of a unified workforce. New platforms were built around these basic principles:
- Technicians may encounter any new or legacy service in the field;
- Predefined tests with pass/fail criteria reduces technician skill levels and improves MTTR;
- Technicians should have access to references and training in the field;
- Work orders should flow to the technician on the platform; and
- Supervisors and managers must have tools to manage their crews and assets.
The best-in-class platforms achieve these principles through utilization of a true multitasking operating system that interact with a workforce management system. Work orders flow into the management system, where the technician can access an order on their field platform through network access. Predefined tests, with criteria for passing, are included. The technician executes the tests then sends the results back to the management system. A simplified user interface allows them to quickly pin-point and fix problems. If further assistance is required, higher level technicians can view the results on the management system, or control the user interface of the set through any web browser, even those on smart phones. These smart test platforms with workforce management are how communications companies can address the need for a single truck roll with a single technician to activate and maintain any service.
Technicians are always on the move, which is another reason that proper training is so difficult. Smart test platforms integrate a learning management system with short 10-minute courses. A supervisor or manager could specify a curriculum for a technician, and that technician could complete courses at work or home through the Internet, or directly on the platform, as they have time. Supervisors can track the progress of their technicians and recommend remedial or advanced training. The technician can refer back to a particular subject and refresh him or herself in minutes, before walking into the customer premises.
Workforce management systems allow supervisors and managers to measure their field force’s performance and track assets. For the first time, they can accurately measure the performance of crews by territory, market, region, etc. Additionally, they will be able to track and manage field assets, to determine where they are located and who is using them. These features provide for easy reallocation to optimize the use of capital investments.
Utilizing integrated smart test platforms, along with workforce management, helps communications companies achieve that lofty goal of the universal technician. Technicians do more in less time while having the resources available for them to quickly execute the work order. Communications providers are able to deliver services quicker and keep customers satisfied.
June 15, 2011, by Mark Milliman
The Changing Face of the Field Technician, Part I
Communications companies have been facing tremendous changes in their field workforce for the past several years. New technologies are being introduced in the network which are far more complex than previously, and the experienced technician with knowledge of legacy services is retiring. New technicians are coming into the field, but there is a knowledge and experience gap. Communications companies are struggling to bridge those two divides, butthey are challenged with decreasing operational budgets limiting the purchase of new equipment and training. A typical new field technician receives 25% to 33% of the training that their counterpart received two decades ago. Additionally, they are required to cover traditional legacy services and new complex services like VoIP, IP-TV, and VPLS, to name a few. Supervisors and managers are asking how their technicians can cover more services with less training.
Meanwhile, operations management want to streamline the process of installing and maintaining services in the field. Serving a small business with five lines of telephony, plus some Internet access, has traditionally required a minimum of two or three truck rolls. The first technician would arrive at the customer’s premises to install the NIU and turn up the T1. A second technician would be dispatched to install the integrated access device to split out the voice and data services, and sometimes a third technician would come out to test and activate the voice and data services. At approximately $200 per service call, the installation and commissioning cost at least $400-600. Additionally, the time required to coordinate all of the installation activities would take weeks, not days as desired. Similar processes can be detailed for a retail FTTH or cable installation. Operations management realized the inefficiencies of multiple truck rolls, so they decided that their technicians should not be specialists; they should be generalists.
In theory, the decision that field technicians should know all layers of the services they provide is the right one, provided they are trained and equipped with the right knowledge and tools. The execution of this objective is where most companies fell short. Communications companies have struggled the first decade of this century. First it was the tech crash after the bubble burst in 2001, and lately the global recession has forced companies to look for ways to cut back expenses. Training and corporate development is frequently viewed as one of those items that can be cut to trim budgets. So just as operations managers and supervisors were beginning to cross-train their workforce, their Vice Presidents and Directors told them to reduce training expenses.
The evolution of field equipment to support their transition was not faring any better. Field test sets were still predominantly single purpose handhelds with obtuse user interfaces. Most vendors sold modular sets with plug-ins providing additional interfaces or protocols, but they were not service oriented. Technicians had to be familiar with how protocols work and how lower layer problems manifest themselves at the service level. Even as the test sets covered more technologies, field operations budgets were being reduced, so the full impact of a cross-trained staff could not be realized.
This is the state-of-affairs today where technicians are expected to do more without the tools or training to support them. The next installment will address how carriers are viewing field operations from a holistic view and how field test vendors are responding with workforce management solution.
May 24, 2011, by Steve Manuel
Challenges Facing Utility Networks
I recently visited the Utilities Telecom Council (UTC ) EXPO 2011 conference in Long Beach California, where utility industry leaders gather to discuss critical telecommunications issues and technology which have significant implications to the deployment, support and security of utilities infrastructure.
It was very interesting to see the array of vendors who are promoting technology, systems and services in support of smart energy management and infrastructure security. SCADA, Teleprotection, Automatic Meter Reading (AMR), Advanced Meter Infrastructure (AMI), Outage Management System (OMS), Work Force Management Systems (WFMS), Automatic Vehicle Location (AVL), and Distribution Automation (DA) are just a few of the key mission critical applications that utilities rely upon for their daily operations, as highlighted at the conference. These mission critical applications require high availability, low delay, and fault tolerant networks. And now, more than ever before, converged backbone networks must be tested thoroughly to work as advertised.
With an increasingly complicated mix of legacy and modern architectures to support, I could not help but think about how utility companies must be facing real challenges in terms of equipping their field staff to handle these complex installation, troubleshooting and maintenance issues. It seems that today’s centralized and network-embedded test capabilities employed by utility operators are helpful but incomplete.
It became quite clear that an effective strategy for increasing reliability and performance of complex utility networks should include comprehensive, field-portable testing.
Here is just a sample of the testing requirement faced by these utilities today in terms of critical communications links:
HS or P2P||Endpoint
Data Rate/Date Volume||Latency
|Smart Grid - Smart Metering||HS||Low/Very
|Smart Grid - Distribution Automation||HS
|Smart Grid - Distribution Energy Management/Control
(includes ADR, storage, PEV, PHEV)||HS,
|Smart Grid - Micro Grid Management (between EMSs)||HS,
|Mobile Workforce (push-to-X)||HS||Low/Low||Low||High||High
|Enterprise (corporate) Data||HS||Medium/Low||Medium||Medium||Medium|
|Enterprise (corporate) Voice||P2P||Low/Very
This matrix depicts the challenges associated with network testing, particularly in the field. The importance of testing across all deployment phases grows as the need for reliability and performance increases. Field testing complements other network diagnostic capabilities being built into the networks. The key requirements for use of field test equipment in utilities include proven ruggedness, comprehensive network interface support, multi-layer network verification, and clear upgradability to support new network services. With the rapid evolution of Smart Grid, field test set modularity is ever more important. There will be more new interfaces to support, while protecting existing tool investments. Utility network engineers don’t want to carry multiple types of test sets into the field.
Smart, modular equipment which could provide robust and complete testing and verification options across the variety of network configurations and help answers these concerns, as they have in telecom; communications technology as applied to utilities was a featured topic at the conference. Furthermore, workflow management system can be tightly integrated with modular test equipment. This integration can go a long way to improving the productivity and effectiveness of the field force challenged with the deployment and upkeep of this critical infrastructure.
May 10, 2011, by Ildefonso Polo
Propagation Delay or Round Trip Delay (RTD)
Often we are asked to confirm whether or not our transport products can measure RTD; different names are commonly used for this test, and so confusion abounds.
In general RTD refers to the time it takes for a single bit (Unit Interval or UI) to travel to a distant loopback and come back to the originating point. One half of the RTD would be equivalent to the one-way latency, which includes the effects of physical media and active devices in the link under test. RTD is often used to verify the physical position of a hard or ‘soft’ loop and to compare the delay with a previously recorded value for that link (e.g. new path, new network elements, etc.)
YES, most of our transport products (except for the MTT-38) measure the RTD down to 1 micro second and in UI.
On a recent benchmark test between our SunSet 10G+ and a competitor's module, we found that the competitor’s unit does a poor job at this test due to it poor resolution (0.01 ms) and the lack of UI. Not showing UI is a result of its poor resolution, which is not even enough for E1 (UI = 488 ns), so a direct measurement or conversion is not possible. A resolution of 0.01 ms is equivalent to an error margin of 2 km (1.26 mi), while Sunrise Telecom’s instruments can even measure their own internal delay, which is around 2 to 3 μs for SunSet 10G+.
What does all this mean for practical purposes? Well, the competitor would not be able to give any clear indication for links shorter that 1km or pinpoint loops within ±1km, and it would not be suitable for checking the health or impact of network elements, paths or mappings changes. On top of that, the competitor does not display RTD until it is set to a specific configuration, which took us quite some time to figure it out.
Why don’t they need calibration? Well, their resolution is so poor that the instrument’s internal delay (around 2 μs) becomes insignificant and immeasurable. Compensating for 2 μs would not make any difference to their already poor resolution. For that same reason, the competitor may not even be capable of discerning the changes in delay introduced by network elements.
In general, our products do a far better, more precise and useful job at measuring RTD. Our calibration feature allows our products to measure RTD down to 1 μs resolution and detect small changes in RTD due to network elements or their configuration.
April 19, 2011, by Lance Moore
E1/T1 Frequncy Synchronization Testing Tip
Frequency synchronization can be a problem when:
- the customer purchases a channelized E1/DS1 circuit.
- the customer’s circuit passes through a synchronous network element such as an exchange, PBX, or a digital cross-connect.
- the E1/DS1 circuit passes through more than one carrier.
Frequency synchronization problems result in bit slips, a major source of service impairment. See the figure for the setup, and identify frequency synchronization problems in your results.
Observe if the frequency value varies from the 2.048 or 1.544 MHz reference frequency. You will see >>> or <<<, indicating the rate of frequency slippage.
Note the (+/-) Wander values This will provide an indication of any low frequency variation in the signal’s frequency.
April 12, 2011, by Lance Moore
Interview with Forouzan Hojjat, product manager for, among other things, the XTT 5000, which offers IntelliSAM. IntelliSAM implements the new Carrier Ethernet Y.1564 standard.
Lance: Does Y.1564 and IntelliSAM make testing Carrier Ethernet easier or harder?
Forouzan: IntelliSAM is pass/fail, which is easier. You can be running a test for seven services, and have a result for each service, and one result for all of the services together. it's a complete pass/fail approach to testing. We've also color-coded. If the result is green, it was successful, if it was yellow it means the test didn't finish, or hasn't started yet, and if it's red, it means that the test failed.
Lance: So you have an 'at a glance' feature?
Forouzan: Right. You can take a look and see that the test failed or passed. You can also save the profile. The technician will have a set of defined profiles; load them, run the test, and see the results quickly.
Lance: What should a test profile consist of?
Forouzan: A test profile includes service level agreement (SLA) information, and the bandwidth levels which are part of a service carrier's portfolio. For example, they may have 2 Mb/s, with an SLA of 'x' delay and 'y' packet loss, etc. They may have a 'gold' service, a 'silver' serivce; you have bandwidth information on each of those, entered in the profile. The whole test can go in the profile in the XTT 5000; which tests to run, which services to test, how many services to test, everything. So when they go to a customer, they can just update the addressing information and run the test.
Forouzan: Everything has a verdict, with this test approach. With RFC2544, only the maximum bandwidth before a frame is lost measured. That's not way it works with Y1564 works. It tests exactly what is sold; if 50 Mb/s are sold, we would test 50 Mb/s, and measure SLAs to make sure SLAs are met. IntelliSAM measurement results are much more reliable, because the measurements are done on every single frame. That's also why IntelliSAM is much more accurate. IntelliSAM provides frame delay variation measurement, and measures Availability, which exists in many SLAs, and is not provided for by RFC2544 at all.
Forouzan: IntelliSAM provides dedicated standard procedures for every type of traffic. For example, if you have best-effort traffic we provide measurement results for yellow traffic, which is best effort, and another set of results for green traffic, which is committed traffic. We make a difference between these two, which is good when you're in a network which is color-aware.
RFC2554 vs IntelliSAM Testing
|Deficiencies of RFC2544||Results in||IntelliSAM’s Answer|
|Cannot test committed rate to service level agreements||What
is sold is not tested||
- Tests committed bandwidth, burst and SLA
- Tests Best Effort bandwidth, burst and SLA
- Tests policing unauthorized bandwidth
|Long test. Many permutations are tested||Unnecessary,
time wasted||IntelliSAM can test each configured
service in minutes
|To overcome RFC2544 deficiencies, vendor specific tests
have been implemented||Service Provider
Interoperability problems||Y.1564 is better than
all the vendor-specific RFC2544 implementations. IntelliSAM is first to
support Y.1564. Y.1564 promotes interoperability
|Does not provide for multiple streams||
- Does not test service multiplexing
- Is not realistic
|IntelliSAM’s Service performance test can test
up to 16 services at the same time
|Designed for device benchmarking- does not test to the
sold bandwidth but to the device traffic limit. Measures recovery time from
power-off and software reset||Will crash the
network if applied rigorously to live network||Tests
the sold bandwidth, without harming the network:
- Other in-service traffic not effected
- Network equipment not “broken” and powered off as a result of the
|Tests Frame Latency on one frame every 2 minutes||Poor
statistical validity||Tests frame latency on every
|Does not have Frame Delay Variation measurement||Feature
not tested||Provides Frame Delay Variation
|Does not provide Availability||Missing
availability, invalid FLR, FTD||Has Availability;
Measures FD, FDV, FLR measurements during available time per ITU-T
April 5, 2011, by Lance Moore
Did you know Sunrise Telecom has a video channel on youtube? See the latest RxT Smart Productivity Test Platform video right now. Then, press Subscribe to catch new videos (demos, training, product information) as they become available.
You can also always search for "sunrise telecom" to see other videos as well. Let us know what you think by leaving a comment, here or on youtube!
March 31, 2011, by Jerry Green
Use this table to understand how DOCSIS has evolved. DOCSIS 3.0 is the latest industry standard.
|DOCSIS 1.0||Mar-97||First standard for data over HFC Network||Reduce modem costs|
|Best effort IP data service only||Internet access|
|DOCSIS 1.1||Apr-99||QoS||Support time sensitive services (VOIP)
|Baseline Privacy Interface (BPI+)||Improved Security
|Pre-Equalization||Improved US preformance
|Management tools||Better CM control
|DOCSIS 2.0||Dec-01||S-CDMA/TDMA||More robust against interference
|Upstream rate increase to 27Mbps||Improved upstream speeds
|Supports 256 QAM on Downstream (32Mbps)||Improved downstream speeds
|DOCSIS 3.0||Aug-06||Bonded Channels||Higher data rates|
|Load balancing||Improved capacity management|
|Expanded US freq. range to 85MHz||Increase capacity|
|IPv6||More IP addresses|
|Multicasting support||Switched Video & IPTV support|
|Enhanced management tools||Better modem management|
March 22, 2011, from documentation by Paul Marshall, CTO
Carrier Ethernet Testing: Advantages of Y.1564 over RFC 2544
Only Y.1564 allows you to verify the purchased bandwidth profile configuration and performance to the service level agreement (SLA) of a Carrier Ethernet service. Here are the testing advantages:
- Verifies configuration and performance of CIR/CBS/EIR/EBS/CM
- Faster method
- Multiple streams tested, not just one
- Tests network rather than a single device
- Tests to SLA rather than to network failure
- No time wasted on excessive permutations
- Latency test tremendously improved and made on every frame
- Measured during normal operation when SLA should be met
- Adds frame delay variation
- Skips tests designed to crash the network
- Availability results calculated and presented to technician
- Guidance for using and resolving differences in information rate and utilized line rate
See IntelliSAM for more information on Y.1564 testing.
March 15, 2011, by Lance Moore
First up, I present you an interview with CEO Bahaa Moukadam. Bahaa joined Sunrise Telecom as VP of Marketing, and later took on the responsibilities of CEO. He has more than 20 years of executive leadership rich in performance-based achievements, with a strong blend of business savvy, expertise and deep knowledge of the high-tech industry.
Lance: Sunrise has a new catch phrase, “Productivity Rising.” What spurred this new focus? What was the thinking there?
Bahaa: The thinking here is a lot of people are focused on testing, on test widgets, on having the best testers ... these are important and will continue to be important, but right now in addition, the big focus is on how do we improve the productivity of the technician?
Lance: Why that focus now?
Bahaa: Communication Service Providers (CSPs) are running into severe business pressure around Cost, Competition, and Customer retention. One huge driver is that networks are complicated and overloaded, so CSPs have to upgrade the network, which costs a lot of money.
They have top-line pressures because there is more competition, and prices are going down. One way to compensate for that is to improve the productivity of the technician. By improving productivity they can reduce their expenses, and make it a lot better to move forward. And we realized that.
We are the experts at providing the best testers, but how do we combine our tech expertise, and also address the business issues of our customers? That was the birth of the idea of the RxT.
RxT has taken our invention of the modular test set, which continues to be very important, to the next level. People are exposed to a lot of technologies, so they need to be able to change technologies, and evolve in the same tester, but they also need to link that to the back office, to save and analyze results. They want to figure out common threads; how can they change the work flow of the technician to make them more productive? If you make the technician five or ten percent more productive, and multiply that by a hundred or thousand technicians, that's a huge business impact.
Another aspect of productivity is the any where, any time remote access. If the technician is out in the field and they're stuck, they can't do an installation successfully or they can't troubleshoot a problem, in the past they would've packed up and went home, and said “Hey, I have to reschedule another visit by somebody else.” Now, with the RxT, while they're there in the middle of things, they can call in for help, and somebody can dial in remotely to the RxT tester, guide them through it, and fix the problem on the spot. It solves the isolation of the technician problem. Fixing the problem right now gives higher customer satisfaction, as they're not hearing we have to schedule another appt, and the CSP is reducing costs as they don't have to do another truck roll.
Lance: It sounds like the focus is on mixing technologies and back office access... is that something Sunrise Telecom is going to do other things with going forward?
Bahaa: One huge thing with the RxT, that no one has ever done in the entire industry, that's a key part of the strategy... is to go back to being really aware of the cost pressure of our customers, and take specific steps to reduce their CapEx spending. This is where the idea of forward compatibility came from.
What that means is is that a lot of our customers have been loyal, and invested in the MTT platform, and they have a lot of MTT test modules. For the first time ever we're allowing existing customers to transition many older modules and move it forward into the RxT platform, saving a huge amount of capex.
What typically happens in the industry, is that when a vendors comes out with a new platform, there is a hard cut. For the CSP to get to the new platform, they have to buy everything new. In our case, there's forward compatibility, which significantly reduces capex exposure of our customers.
Lance: Is there any way “productivity rising” applies as a concpet to Sunrise Telecom?
Bahaa: Yes, absolutely. One of the things we're doing internally to improve productivity, is really linked back to the fact that RxT allows us to reduce the number of platforms. When we reduce that number of platforms, we can target our R&D resources to fewer platforms. That allows us to add a lot of test capabilities faster and to innovate more, because we're doing it on fewer platforms. We can create more useful content.
Lance: Is there anything else you want to add?
Bahaa: RxT is a really great, great platform. Another dimension to that focus on productivity is understanding that our customers also need a lot of training and consulting. So we are expanding, and offering a richer set of training, both on technology and products, to make our customers more efficient. We're rolling out a series of offerings around training and implementation, and consulting services.