Yahoo Finance

This dynamic was further compounded by integration complexity and adding disparate product lines that carried different pricing models, profitability levels, and value propositions. As we move forward, we believe that that these severe headwinds have largely receded. At the same time, we are excited about our potential to benefit from new tailwinds related to our new product innovation in security and analytics, and the continued migration to increasing software content. To summarize these unique dynamics, we have stabilized revenue from our two largest service provider customers in fiscal year 2019.

We have successfully migrated most of our other tier-one operators over the past two years to our software-based platform for service assurance. Service provider-related revenue for the ISNG software platform grew by nearly 40% and it represented nearly 30% of our carrier-related service assurance product revenue last year. We have stabilized overall DDoS revenue during the second half of the year primarily due to improved enterprise traction. We have completed our R&D projects to integrate key products and technologies that were acquired as part of the Danaher Communications business acquisition.

And we have divested certain product lines that were unprofitable and had been in decline for multiple years. At the same time, we made good progress on many other fronts such as solid execution of our product strategy. We reshaped our product portfolio to focus on higher-margin, software-centric solutions. We broadened our range of solutions to provide visibility across any type of infrastructure into any service or applications.

We now provide greater deployment flexibility ranging from appliances to software and virtual form factors. And our solutions address an expanded range of use cases, from network, application, and infrastructure performance management to security and big data. We have begun to build sales momentum in our enterprise customer segment as customers start to move forward with digital transformation initiatives. We've reported three consecutive quarters of solid organic revenue growth in our enterprise customer segment.

We completed the restructuring that began in the second quarter of last year. We expect that these actions will generate annual run-rate savings of approximately $23 million split between fiscal years 2019 and 2020. By restructuring key operations, selling non-core product lines, and carefully managing spending, we reduced operating costs by 9% in fiscal year 2019, and we believe that those actions will also help us keep costs relatively flat in the coming year. And finally, we recently realigned leadership roles, and the overall structure for our technical, product delivery, and sales organizations in order to maximize our ability to accelerate key development initiatives and drive go-to-market effectiveness.

Moving to Slide 8, we believe that NetScout's focus on providing ultra, high-definition visibility into the real-time transactions embedded in network traffic is increasingly resonating with our customers who are challenged to efficiently and effectively transform, and protect their infrastructures to support digital transformation without compromising their current capabilities. We recently held our annual technology and user summit, where we shared our product roadmaps for the coming year and the feedback from customers, partners, and various industry analysts was very positive. As we move forward, we are focused on capitalizing on the following near and longer-term opportunities to drive top-line growth. In the enterprise, we see good scope for continuing to help our customers with their data center transformation initiatives, particularly as they migrate more of their application workloads to private and public cloud environments and improve overall agility.

Security represents a promising adjacency as our value proposition expands beyond DDoS. We are looking to build on the early momentum we gained with last year's launch of Arbor Edge Defense, which adds powerful new threat intelligence gateway capabilities to our proven set of enterprise DDoS capabilities. We plan to launch Arbor Threat Analytics within the next couple of months. This is a new enterprise security offering that takes advantage of NetScout's existing footprint inside our enterprise customers' network infrastructure.

This analytic platform combines our historical strength in packet forensics with Arbor's robust catalog of known security threats and new machine learning capabilities, thereby enabling security teams to work faster, and more efficiently to identify and investigate potential network-based security breaches. Combining Arbor's sales resources with our large service assurance enterprise sales teams was the final step in completing our integration efforts. With this behind us, we move forward with improved coverage, especially in certain international markets, and have strengthened our ability to maximize cross-selling opportunities across network and security operations. In our service provider customer segment, we continue to fortify our incumbency in service assurance, helping carriers add capacity to support growing traffic over their 4G networks while also mining new opportunities for our nGenius business analytics and RAN optimization offerings.

Just as important, we are investing to support our customers as they advance their 5G networks plans. To unlock new DDoS opportunities with our carrier customers, we've continued enhancing our DDoS detection capabilities in ways that can help them improve the overall efficiency of their network security infrastructure. Let's turn to Slide No.9, as I would like to focus on our outlook for fiscal year 2020 and offer some closing thoughts. We remain bullish on the opportunities we see and confident in our ability to capitalize on them.

As we've described, we believe that many of the issues that have limited our topline results are behind us as we focus on maximizing the upside from a number of growth initiatives that are still in their early stages. As we move into fiscal year 2020, our top priority is to produce top-line growth, which is fundamental to driving operating leverage, EPS growth, and stronger free cash flow. Our fiscal year '20 plan is to generate low-single digit organic revenue growth through a mid-single digit increase in product revenue growth, which at the higher end of our plan can then be converted into mid-single digit EPS growth. Looking more closely at our fiscal year 2020 revenue target that ranges from $895 million to $915 million, we have built our plan around the following assumptions.

We expect our revenue growth will be driven by higher product revenue in our enterprise customer segment as we see good opportunity to sustain the organic growth we've generated in recent quarters. Although we are very bullish on the long-term prospects for our new Arbor Threat Analytics, we anticipate relatively minimal contributions from this offering this year, given the early summer launch and conventional sales cycles. We expect that the near-term service provider spending environment for both service assurance and DDoS security will remain difficult. While we expect 5G to be a catalyst for better spending over the longer term, this technology turn remains in its early phase.

Nevertheless, we anticipate another good year in capturing 5G calibration deals and we have recently won several initial deals for 5G radio access network monitoring with tier-one operators in North America. However, these carriers are moving cautiously to build out their 5G stand-alone architectures, which will ultimately require investment in new service assurance solutions. In terms of diluted EPS guidance, we anticipate fiscal year 2020 diluted EPS in the range from $1.40 to $1.45 based on our plans for organic revenue growth, plus further gross margin improvement as the product mix continues to shift toward the software content. And basically, flat operating expenses compared with last year's reported operating costs.

That will enable us to deliver EPS growth even with an anticipated increase in our tax rate. Before I close my commentary, I wanted to provide a brief update on changes to our board of directors. Michael Szabados, who has made extensive contributions to NetScout's success in senior leadership roles including the past 12 years as our COO, and Vivian Vitale, a highly respected and experienced HR leader with top technology companies, were appointed to our board earlier this year. Michael will serve as vice chairman of the board.

At the same time, Vin Mullarkey, a long-standing NetScout director, retired and I would like to thank Vin for his service and support over the past two decades. Finally, I would like to thank my fellow Guardians around the world for their tireless efforts and dedication. I believe that we move forward having assembled a world-class, experienced team that possesses unmatched domain expertise, and is focused on the stellar execution of our plans this year. I look forward to sharing our continued progress and achievements with you over the course of the coming year, and I'll turn the call over to Michael at this point.

Michael Szabados -- Vice Chairman and Chief Operating Officer

Thank you Anil, and good morning everyone. Slide 11 outlines the areas I will cover. As Anil mentioned, we held our annual technology and user forum, Engage, last month in Nashville. It was a resounding success with 700-plus attendees spanning our service provider, enterprise, government, and partner universe.

Across both customer segments, digital transformation has become the common theme. We are well-positioned to help our customers reduce the risks and maximize the rewards of their highest impact digital transformation initiatives that include 5G, cloud, application performance, and security. I will intersperse some additional observations from Engage as I cover several notable wins from the past quarter. In the service provider market, carrier marketing around 5G is increasing, although the infrastructure build-out and rollout of 5G services is moving at a more measured pace.

Our recent success with a tier one U.S. service provider demonstrates our potential to leverage our 4G incumbency to win new 5G-related projects and participate in all phases of the 5G network lifecycle. In the fourth quarter, this carrier awarded us a mid-seven figure deal to help calibrate the design of its 5G radio access network or RAN. This long-standing customer is also starting to deploy our 5G-compatible RAN monitoring tools, as they begin to launch new 5G-related services in limited markets.

In the enterprise, our range of integrated offerings is enabling our enterprise customers to move forward with major data center transformation and multi-cloud migration strategies. To that end, we have continued to advance our relationships with major public cloud vendors like AWS and Microsoft Azure. NetScout is now an advanced technology partner at AWS and we have recently achieved a co-sell ready status with Microsoft Azure. This enables us to actively collaborate with Microsoft's sales teams to support customers who are migrating and managing applications in hybrid Azure environments.

As customers seek greater visibility into application performance, our nGeniusPULSE offering is becoming increasingly valuable. PULSE is an active transaction-testing tool that complements our core portfolio of passive monitoring solutions. It is gaining traction with customers who can use it to ensure basic connectivity, manage the availability, reliability, and performance of Software as a Service or SaaS applications, and monitor infrastructure performance. We are seeing good interest in this product as measured by -- indicated by our PULSE revenue nearly doubling last year off a relatively small base.

The product is almost always sold in tandem with our core products. And a number of active trials continues to grow every quarter. During the fourth quarter, a long-standing financial services customer spent over a quarter of a million dollars on nGeniusPULSE to monitor connectivity at over 150 offices, data centers, and mission-critical call centers nationwide. This is just one part of a much larger deployment of NetScout technology that is helping the customer baseline existing dependencies, support evolving data center requirements, and deploy a new cloud platform.

We see additional opportunities to further expand the scope of our engagement as this customer is actively evaluating PULSE's WiFi monitoring capabilities. Turning to security, we are executing on our strategy to expand beyond DDoS. At Engage last month, we unveiled ATA, or Arbor Threat Analytics, a new enterprise security analytics software stack to detect and investigate potential security breaches using our ISNG and vStream data sources. This new security product builds on our ability to support forensic use cases with our valuable packet data that can aid security teams as they seek to understand where and how they have been infiltrated.

For example, last quarter, the cybersecurity organization at a large Midwest financial services firm selected NetScout to support a multi-phased project aimed at compliance with new state regulations that mandate the collection of forensic evidence for investigation into potential security breaches. The new Arbor Threat Analytics is designed to make this even easier for customers, like this customer, to benefit through easy access to our IP packet recording at scale; a robust threat intelligence feed that can help quickly detect known threats that have already penetrated existing defenses; new capabilities that rapidly identify anomalous behavior on the network; and integration with third-party security information and event or CEM platforms. I look forward to sharing additional news of our success in expanding our customer relationships in fiscal year 2020. That concludes my prepared remarks and at this point, I will turn the call over to Jean.

Jean Bua -- Chief Financial Officer, Chief Accounting Officer, and Treasurer

Thank you, Michael, and good morning everyone. I plan to review key fourth quarter and full year metrics, along with our guidance for fiscal year 2020. As a reminder, this review focuses on our non-GAAP results unless otherwise stated, and all reconciliations with our GAAP results appear in the presentation appendix. In addition, due to the sale of the HNT tools business in mid-September, I will highlight certain revenue trends on an organic non-GAAP basis, which removes HNT tools revenue for the applicable period referenced.

Regardless, I will be sure to note the nature of any such comparisons. Slide No.13 details our results for the fourth quarter and full fiscal year 2019. Focusing on the quarterly performance, we reported revenue of $235.2 million. Fourth quarter revenue declined by 1% on a year-over-year basis, but grew at 3% on an organic basis excluding the HNT tools business.

Revenue in the service provider customer segment was relatively flat while our enterprise customer segment grew 8% organically. On a comparable organic basis, product revenue grew nearly 9% and service revenue decreased 2%. Our fourth-quarter fiscal year 2019 gross margin was 79%, or a 2.3 percentage point increase from the same quarter last year largely due to favorable product mix shifts. Quarterly operating expenses were down by 17% from the prior year due to lower personnel costs primarily resulting from lower headcount.

We reported an operating profit margin of 29.2% with diluted earnings per share of $0.66, which ended up higher than our April 9th estimate due to a lower-than-expected tax rate, as we finalized our year-end numbers under the first full year of implementing the new tax code. As Anil mentioned, we completed our restructuring program during the fourth quarter. We ended the fiscal year with 2,581 employees, which is a 14.5% reduction from a year ago. In fiscal year 2019, we saved a total of $10 million from our restructuring actions, which impacted our third and fourth fiscal quarters.

For fiscal year 2020, we expect an additional $13 million in savings, which will impact our first and second quarters. This will result in a total run rate savings of about $23 million. In total, restructuring payments were approximately $17 million and that is reflected in our free cash flow results for fiscal year 2019. There are no material restructuring payments associated with these programs anticipated in fiscal year 2020.

Turning to slide 14, I'd like to review key revenue trends. Fiscal year 2019 revenue in the service provider customer segment declined by 13% with service assurance down 10% and DDoS security down 20%. In the enterprise segment, fiscal year 2019 revenue declined 4%t due to the sale of the HNT tools business. On an organic basis, enterprise revenue grew nearly 2% for the year.

In terms of other full-year revenue trends, total revenue was evenly split between our enterprise and service provider customer segments. In terms of revenue by geography, which is calculated on a GAAP basis and includes revenue from the HNT tools business, the U.S. experienced a 5% revenue decrease while international revenue declined by 12%. International customers represented 39% of GAAP revenue versus 41% last year.

We had no customers who represented 10% or more of revenue in either the quarter or the year. Slide 15 details our balance sheet highlights and free cash flow. We ended the quarter with cash, cash equivalents, short-term marketable securities and long-term marketable securities of $487 million, which is an increase of $11.2 million since the end of the third quarter. We generated free cash flow of $76.4 million for the quarter.

In addition to repurchasing $14.5 million of our common stock in the quarter, we also repaid $50 million of the $600 million that was outstanding on our existing credit facility. For the full year, we generated free cash flow of just over $126 million, which includes the previously noted restructuring payments of $17 million. Excluding the restructuring payments, our free cash flow conversion was 131% of non-GAAP net income and it was 116% conversion on the reported free cash flow. To briefly recap other balance sheet highlights, accounts receivable, net, were $235.3 million, up by $21.9 million at the end of the last fiscal year.

DSOs were 88 days versus 78 days at the end of fiscal year 2018 and 91 days at the end of December. The increase from last year's level primarily reflected the timing of large maintenance renewals. I'd like to provide a brief update on our use of capital. Moving forward, we plan to retain up to $300 million in cash on our balance sheet at any given point for both working capital purposes and in consideration of overseas cash.

In the near term, we plan to allocate up to $100 million for stock buyback and debt repayment. We anticipate being active in the market in the first quarter for share repurchases, depending on market conditions and subject to daily trading volumes and price considerations. Let's move to slide 16 for guidance. I will focus my review on our non-GAAP guidance.

As a reminder, we sold the HNT tools business in September 2018 and it contributed $18 million to last year's revenue before the sale was completed. Accordingly, the impact of the divestiture should be taken into consideration when comparing fiscal years 2019 and 2020, especially for the first two quarters of both years. Slide 24 in the appendix details the HNT tools quarterly revenue contribution to last year's revenue. Consistent with Anil's comments earlier, we are currently targeting fiscal year 2020 revenue in the range of $895 million to $915 million, which implies low single-digit organic growth.

In terms of the other key fiscal 2020 operating model assumptions outlined on this slide, we currently anticipate further gross margin improvement as we drive adoption of our software solutions. Our plan currently calls for relatively flat operating costs compared with last year. We anticipate that savings from last year's cost-reduction actions will enable us to absorb incremental spending tied primarily to higher compensation costs associated with annual merit adjustments and critical personnel replacements, as well as additional investment in our enterprise security initiatives. We expect to deliver earnings growth despite an anticipated increase in our effective tax rate to between 23% and 25% as certain components of the new tax code are scheduled to increase.

We are currently evaluating certain tax strategies that may enable us to keep the tax rate relatively flat with the prior year. Assuming 78.2 million shares outstanding, we currently expect diluted EPS between $1.40 and $1.45. I'd also like to offer some additional color on the first quarter. As a reminder, last year's first-quarter revenue of $206 million included $10.4 million from the HNT tools business.

As we assess the opportunities in front of us, we currently anticipate flat to 1% organic revenue growth, which equates to revenue in the range of $195 million to $200 million. We currently anticipate that around 46% of our expected annual revenue will come in the first half of the year. We are planning for modest gross margin improvement in the first quarter with operating expenses in the range of 6% to 7% lower than the same quarter one year ago. Diluted earnings per share for the first quarter is expected to range from $0.06 to $0.08.

That concludes my formal review of our financial results. Before we transition to Q&A, I'd like to quickly note that our IR conference participation is listed on Slide 17. I'll now turn the call over to the Operator to start Q&A.

Questions & Answers:

Operator

[Operator instructions] We'll take our first question from Matt Hedberg with RBC Capital.

Matt Hedberg -- RBC Capital Markets -- Analyst

Oh, hey guys. Thanks for the prepared remarks and the call here. In your prepared remarks, you outlined some of the assumptions of getting to low single digit growth in fiscal '20 here. And I guess in the enterprise segment in particular, you noted contributions or I guess I'd say minimal contributions from some of the new Arbor Threat Products.

But can you give us a little bit more granularity about when you think about this sustained enterprise growth? What are some of the key drivers that we should be watching as the year progress on the enterprise side?

Anil Singhal -- Chief Executive Officer

So Matt, we talked about -- when we talked about the Arbor product, we wanted to make sure there's no confusion between the previous product from Arbor, Arbor Edge Defense, and other products in the DDoS area from the new product called Arbor Threat Analytics. So we are saying minimum traction or some contribution, especially in the second half of the year on the ATA product called the Arbor Threat Analytics. But there is a good cross-selling potential as we have combined across all forces. Only about 10% of the NetScout enterprise customers use the Arbor DDoS and Arbor Edge Defense product.

So that's one area. Other is that in the data center transformation, our ability to allow people to get a single pane of glass for before and after, in the cloud, on-prem, server farm visibility is a new area, which is generating a lot of interest. So those are the two big reasons in the short-term why we expect enterprise revenue growth and we think there will be sufficient growth overall as a result of that in the single digit, despite the fact that there will be continued challenges on the service provider side, even though we think most of the challenges have bottomed out.

Matt Hedberg -- RBC Capital Markets -- Analyst

That's sup -- that's helpful. Then maybe as a follow-up, Michael commented about advancements with AWS and Azure. And that kind of caught my attention. I know we've talked about this in the past for you guys, but maybe a little bit of an update about how that relationship or how those relationships, I should say, should not only help customers but also how you kind of think about that eventually impacting your growth.

Anil Singhal -- Chief Executive Officer

Well, we are now an APN member, which is advanced partner network remember with AWS. And that means that they can and do reference us in working with their customers in their migration projects. So we are now part of the portfolio of vendors that AWS is publicly referencing as helpful or being part of a migration project. In the Microsoft case, because cross-sell ready means that Microsoft sales people are quoted and are credited that is paid on leads that involve NetScout.

Also, any activity that either goes through to Microsoft or even just registering a deal that involves NetScout is remunerative rarity for them. So these are material relationships but I expect that the symbolic nature of it and the fact that we get the credibility from these two top vendors, we are part of the technology platform to migrate. I mean that's where the real impact is going to come over the next year or two. I think just to mention that one of the challenge of deploying on-prem our solution is people's concern that what will happen if I move some of my application assets to Azure or AWS.

So regardless of how much revenue we get numerically from this relationship, that burden is taken away and people don't have second thoughts on deploying your solution because they feel that it's going to be evergreen no matter where they are on the application. So these relationships that Michael mentioned sometimes are just a check off item, sometimes create confidence for people, and then other items it cuts down the sales cycle because people don't have any fear that what's going to happen to their investment as they migrate their apps or workloads to the cloud.

Great. Thanks a lot, Matt.

Operator

Our next question comes from Chad Bennett with Craig-Hallum. Your line is open.

Chad Bennett -- Craig-Hallum Capital Group -- Analyst

Great. Thanks for taking my questions. First, the services assurance product revenue. I think you indicate on the call that roughly 30% now is coming from software and it grew roughly 40% year over year last year, which I think is good color.

What are the expectations or embedded expectations for software growth in that segment this year? And obviously, if you answer that, we can figure out where it exits the year, but do you suspect it to sustain that type of growth this year?

Anil Singhal -- Chief Executive Officer

Yeah. Yeah. I mean, this will continue and the goal in this area is over the next 3-year period to get to 70%, 80% of the revenue of service provider. And some portion of the enterprise will come from software.

So yeah, I think expect this trend to continue without maybe going over the exact number. We are -- customers are deciding. We have both options and customers find a better price point for them and it's great for us because it's better margin for us. As a result, it's a win-win for both sides and that's why I think this trend will continue and maybe even accelerate.

Chad Bennett -- Craig-Hallum Capital Group -- Analyst

OK. Then maybe one quick follow-up for me related to that. The top two -- your top two tier-one customers on the service provider side that you indicated have stabilized now, have you had any success in penetrating those two accounts with your software offering? Thanks.

Anil Singhal -- Chief Executive Officer

Yeah. So software offering consists of two parts. One is the analytic applications and other is the instrumentation. Instrumentation is vSTREAM, ISNG, and these two accounts have very, very high deployment of instrumentation maybe to a saturation point on 4G.

So we have not made progress. They don't need anything from us. But on the analytic side, yes, they are buying software. But when they move to 5G, they'll have to use the software version or they would prefer to use the software version.

Last time, these two accounts are dominated by our TekComm products, which were all hardware based. And so because of that, we have not seen traction from them on the 4G side for using the software solutions.

Operator

And we will take our next question from James Fish with Piper Jaffray.

James Fish -- Piper Jaffray -- Analyst

Hi, guys thanks for the questions here. Over the last few years, there's been some movements during the year and so my first one would be what could go right or wrong this year that would make you either exceed or miss your guidance given -- which would pretty much over the next few quarters make it so that NetScout hits their mark here as opposed to the last couple years where we've had some kind of adjustments midyear on the initial guidance.

Anil Singhal -- Chief Executive Officer

Maybe I'll just mention some high level things and maybe Jean can add to that commentary. So I think the dynamics are different than in the last two years. We had -- or last three years. We have heavy reliance on these two providers and that has, as I mentioned, largely bottomed out.

We have more cushion on the margin side. We have reduced the cost structure. All that will provide some headroom. Also, if you notice the last -- we are hoping that this year is less back end loaded in the second half than we had last year.

And so all those things reduces the risk. Unless there is some further change in the service provider segment of the market, which at this point we don't see, I think we feel good about the risk versus reward issue this year.

Jean Bua -- Chief Financial Officer, Chief Accounting Officer, and Treasurer

Yeah, I would only add one thing to what Anil had said is in his remarks he had mentioned that one of the large opportunities that we have, that we've thought about for a few years now going forward, is the ability to cross-sell and to penetrate customers that are Arbor customers that don't use our product or that are legacy NetScout customers that don't use the Arbor product. So that is the good news and as that progresses and takes traction, you know, that should be able to add a significant population to our revenue base. You know, on the downside to that, obviously, that's something that is happening in the first quarter. And so depending on how fast the traction and the integration to the new territories works, you might be able to see some drag in the short-term on that.

James Fish -- Piper Jaffray -- Analyst

Got it. Thanks. And then just one follow-up there. At what point, Anil, do we see service providers move from non-stand-alone mode to stand-alone mode for 5G? And actually, if I can sneak in one more, Jean, I didn't hear anything on the difference on the enterprise business between the security side and the service assurance.

Can you give us the growth rates like you did for the service provider for that business as well? Thanks.

Anil Singhal -- Chief Executive Officer

So while Jean is looking at that. So our instrumentation strategy is very similar for stand-alone versus non-stand-alone. For the current case, we will be using a lot of existing instrumentation. They will not need to do a wholesale upgrade because there are no new links.

So in the short-term, the opportunity for 5G will be less. As they move to the stand-alone mode, there will be additional places to put our technology at the Edge. But our solution and architecture is sort of transparent to stand-alone versus non-stand-alone and if somebody has bought something for non-stand-alone on the existing links, they'll be using it for stand-alone or vice-versa later on. So I think that's a good story but because of these two cases, short-term opportunity for 5G is going to use a lot of the existing instrumentation or at least on the data plan side.

And that will reduce the opportunity in the short-term.

Jean Bua -- Chief Financial Officer, Chief Accounting Officer, and Treasurer

Hi, Jim and just to follow-up question in enterprise, the split between service assurance -- or the growth rates between service assurance and Arbor. In service assurance, the growth was a little less than 1% and that is pro forma as if the tools -- on an organic basis -- as if the tools business hadn't been in there on Q1 over Q1. And then in Arbor, they had a growth rate in the upper single digits. As we've talked about before, Arbor is a Cadillac product, similar to NetScout's NPM products.

And they do very well in very large complex customers. So in the fourth quarter, they were very successful in winning two large deployments into very large financial institutions.

James Fish -- Piper Jaffray -- Analyst

Thanks, Jim.

Operator

And we can take our next question from Alex Kurtz with KeyBanc Capital Markets. Your line is open.

Alex Kurtz -- KeyBanc Capital Markets -- Analyst

Thanks and thanks for sticking me in guys. On the prepared remarks around sales force restructuring or leadership changes, yeah, that's something that seems new to us. So what was done exactly? How serious is it relative to changes that you've done in the past and what areas would we expect to see changes? What verticals?

Anil Singhal -- Chief Executive Officer

So we have on the product delivery side, the change is small. There's a different leader on the Arbor side for the DDoS. Also, we have moved some of the security projects in other parts of the organization to use more resources because we are using the same data for Arbor Threat Analytics as for nGeniusONE. The bigger change is on the sales side.

So we have a single leader, worldwide leader for the sales force and then under that, there is a big leader on the international side and multiple leaders on the U.S. side, sales leaders. And at the account level, a single sales team is now supporting all product sales into that account. And we tried some of those things last year but there were a lot of sales conflicts with artificial quotas and things like that and we didn't have a good impact on that.

So we think to do cross selling, to get the cross selling advantages, which is either selling Arbor products to NetScout account or vice versa, we needed to do this integration. So while it's going to be some disruption, but I think it's going to be more than made up by all the positives of the cross selling arrangement. Because as I mentioned, only there is a 10% account overlap between the NetScout and Arbor customers.

Alex Kurtz -- KeyBanc Capital Markets -- Analyst

No. Had there been leadership changes as far as personnel and reporting structure or are these just changes at the account level, and how accounts are covered?

Anil Singhal -- Chief Executive Officer

Yeah. There are many -- multiple changes at the reporting level but we don't have -- we have not hired people from outside. It's within the sales team there is movement and multiple reporting changes.

Alex Kurtz -- KeyBanc Capital Markets -- Analyst

OK. All right. Thank you.

Operator

We will take our next question from Eric Martinuzzi with Lake Street.

Eric Martinuzzi -- Lake Street Capital Markets, LLC -- Analyst

Yeah, I'd like to take a look backwards just on Q4, the delayed revenue recognition with the international service provider. Wondering if there were any kind of lessons learned as a result of that shortfall, any workflow processes that were needed to be changed.

Anil Singhal -- Chief Executive Officer

Yeah. So the first thing I wanted to mention, Eric, that a good portion of that revenue has already come in, OK. And I think the lesson learned there is that we need to bring -- that when it comes to Asia and sales cycle team, we have to be more conservative moving forward. And these kinds of things happen, and there was a gap of just two weeks.

But nevertheless, it affected because it was the end of the year. So I think that's the lesson learned in the sense that we -- I mean a lot of non-product delays, and paperwork, and other things can extend the sales cycle time. But the good news is that we'll be able to drive this revenue this year, and we already got part of it.

Eric Martinuzzi -- Lake Street Capital Markets, LLC -- Analyst

OK. And speaking of the revenue this year, the question was previously asked kind of what put you at the high end, what put you at the low end but I wanted to frame it a little bit differently, just getting to the high end of what you guys do. Is that going to be probably driven more by enterprise outperformance or is it really going to be driven more by service provider maybe not being as pessimistic as you might have framed it with your stabilization commentary?

Anil Singhal -- Chief Executive Officer

Well, both of them. So it's outperformance versus last year on the enterprise side. And the negative impact of the service provider spending largely bottomed out. So the drag on the upside on enterprise is becoming less and less.

And at the same time, shorter revenue, we have higher margin because of increased software content and the cost reduction exercises we went through last year.

Operator

[Operator instructions] We will take our next question from Kevin Liu with K. Liu and Company. Your line is open. Your line is open.

Kevin Liu -- K. Liu and Company LLC -- Analyst

Hi, good morning.

Anil Singhal -- Chief Executive Officer

Good morning.

Kevin Liu -- K. Liu and Company LLC -- Analyst

Just to follow on the software only deals, are you guys incentivizing your sales team any differently as you head into fiscal '20? Or are your customers just naturally opting for that more so as you make that push toward 70%, 80% product coming from software?

Anil Singhal -- Chief Executive Officer

Yeah. We are not incentivizing it. But we are allowing our sales force to give higher discounts and still get quota credit. So there is a dynamic there that if your flexibility of discounting to the customer on bigger deal sizes is better when you go with the software margins.

So we have some things in place, which allows us to control that.

Kevin Liu -- K. Liu and Company LLC -- Analyst

Got it. And then Jean, last year, I think you provided some long-term targets coming into the fiscal year, calling for mid-single digit revenue growth over the longer-term, low 30% operating margin, and maybe $3 in earnings over kind of a 4-year timeframe. Given some of the changes over the past year, are you guys still on track for that or is there anything that should be updated in terms of either the expectations or the timing of when those are achieved?

Jean Bua -- Chief Financial Officer, Chief Accounting Officer, and Treasurer

So on the earnings call a year ago, Anil had a slide that said he -- based on FY '18 that by the end of fiscal year '22, there would be about mid-single digit CAGR or better, that the growth margin would be in the low 80s and that OPM would be in the low 30s. And so when you look at that, my thoughts are that gross margin is being driven by software only, which has a higher product margin. As well as incredible effect by flow through on revenue -- increased revenue. So that would leave with the operating margins being at the low 30s.

And so today, the cost structure is such that there's probably some rationalization that still should occur to be able to hit those. But the interesting point that I find is if you look at the performance before where the software, the gross margins have gotten close to 80 and the operating margins got close to 29, and you annualize our $235 million worth of revenue, you can see where those targets could still be relatively achievably by the end of FY '22.

Operator

At this time, there are no additional questions. I'd like to turn the program back over to our presenters for any closing remarks.

Andrew Kramer -- Vice President of Investor Relations

Great. Well, I'd like to thank everybody for joining us this morning. I know it's a busy time. We appreciate you making time for NetScout.

Look forward to seeing investors as we appear at different conferences throughout the quarter. If you have questions, please feel free to call me at the Investor Relations number and we'll talk to you at some point as we move into the summer. Thank you.

Operator

[Operator signoff]

Duration: 55 minutes

Call participants:

Anil Singhal -- Chief Executive Officer

Michael Szabados -- Vice Chairman and Chief Operating Officer

Jean Bua -- Chief Financial Officer, Chief Accounting Officer, and Treasurer

Matt Hedberg -- RBC Capital Markets -- Analyst

Chad Bennett -- Craig-Hallum Capital Group -- Analyst

James Fish -- Piper Jaffray -- Analyst

Alex Kurtz -- KeyBanc Capital Markets -- Analyst

Eric Martinuzzi -- Lake Street Capital Markets, LLC -- Analyst

Kevin Liu -- K. Liu and Company LLC -- Analyst

Andrew Kramer -- Vice President of Investor Relations

More NTCT analysis

All earnings call transcripts

This article is a transcript of this conference call produced for The Motley Fool. While we strive for our Foolish Best, there may be errors, omissions, or inaccuracies in this transcript. As with all our articles, The Motley Fool does not assume any responsibility for your use of this content, and we strongly encourage you to do your own research, including listening to the call yourself and reading the company's SEC filings. Please see our Terms and Conditions for additional details, including our Obligatory Capitalized Disclaimers of Liability.

Motley Fool Transcribing has no position in any of the stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy.