Ladies and gentlemen, thank you for standing by, and welcome to NetScout's first- quarter fiscal year 2023 financial results conference call. At this time, all parties are in listen-only mode until the question-answer portion of the call. As a reminder, this call is being recorded. Anthony Piazza, Senior Vice President of Corporate Finance, and his colleagues at NetScout are on the line with us today. If you require operator assistance at any time, please press star zero. I would now like to turn the call over to Anthony Piazza to begin the company's prepared remarks.
Thank you, operator, and good morning, everyone. Welcome to NetScout's first quarter fiscal year 2023 conference call for the period ended June 30, 2022. Joining me today are Anil Singhal, NetScout's President and Chief Executive Officer. In multiple areas within the investor relations section of our website at www.netscout.com, including the IR landing page under Financial Results, the webcast itself, and under Financial Information on the quarterly results page. Moving on to slide number 3. Today's conference call will include forward-looking statements. Examples of forward-looking statements include statements regarding our future financial performance or position, results of operations, business strategy, plans and objectives of management for future operations, and other statements that are not historical facts. You can identify forward-looking statements by their use of forward-looking words such as anticipate, believe, plan, will, should, expect, or other comparable terms.
We caution listeners not to place undue reliance on any forward-looking statements included in this presentation, which speak only as of today's date. These forward-looking statements are subject to known and unknown risks, uncertainties, assumptions, and other factors, including but not limited to those described on this slide and in today's financial results press release. For a more detailed description of the risk factors associated with the company, please refer to the company's annual report on Form 10-K for the fiscal year ended March 31, 2022, on file with the Securities and Exchange Commission. NetScout assumes no obligation to update any forward-looking information contained in this communication or with respect to the announcements described herein. Th e limitations of relying solely on those measures are detailed on this slide and in today's press release.
These measures should not be considered in isolation from or as a substitute for financial information prepared in accordance with GAAP. Today's earnings press release is available on our website. I will now turn the call over to Anil for his prepared remarks. Anil?
Thank you, Tony, and good morning, everyone. Welcome and thank you. We achieved a strong top- and bottom- line performance, extending our business momentum from our last fiscal year into our current fiscal year, 2023, was driven approximately by 20% product revenue growth and approximately 2% service revenue growth, both on a year-over-year basis. During the first quarter, our service assurance revenue grew by approximately 11%, while our security revenue grew by approximately 7%. Our new Omnis solution suite continued to gain more recognition and traction in the marketplace as we further expanded its offerings. For example, we recently launched the Omnis ATLAS Intelligence Feed for smarter automated DDoS attack blocking.
As a new innovative AI-based solution, our Omnis AIF is continuously updated and enables the instantaneous blocking of a large portion of DDoS attacks, thus simplifying operations and minimizing risk for our cybersecurity focus. We recently received the Cyber Defense Magazine Global InfoSec Award for market leader in network detection and response, as well as the Fortress Cybersecurity Award in the threat detection category. Although the total contribution from our new Omnis solution within our security portfolio remains small, relative to our overall revenue, this solution suite continues to show solid potential, and we are seeing our customers' network and security teams beginning to understand. For 7% year-over-year, primarily driven by radio frequency propagation modeling-related revenues. We continue to see carriers invest in their 5G deployments in 2023. This decline was primarily due to the timing of enterprise customer order shipments.
We remain confident in the health of this customer vertical despite these fluctuations in the near term. Enterprises continue to demand best-in-class cybersecurity solution as well as those solutions that can help facilitate the acceleration of their digital transformations. Michael will provide more insight regarding customer orders in our verticals during his remarks. Now let's move to slide number 8 to review our outlook. Looking ahead, we remain excited about the market opportunity we are seeing for both our existing and new solutions. From both a financial and a business perspective, we remain confident in our underlying fundamentals and positioning, despite the persistence of various macro headwinds. As such, we are reiterating our non-GAAP outlook for our full fiscal year 2023. Jen will provide additional color and a recap of the numbers in his remarks.
In summary, new fiscal year is also providing us with a solid foundation going forward. Additionally, we remain encouraged by our ability to help customers address the challenges and opportunities during the remainder of our fiscal year. With that, I'll turn the call over to Michael.
Thank you, Anil, and good morning, everyone. Slide 10 outlines the areas I will be covering today, starting with customers. Continue to see 5G-related activity, both in domestic and international markets. For example, during the first quarter, we received mid-seven-figure orders with 5G-related elements. Now turning to our enterprise customer vertical. In the first quarter, we secured a low seven-figure deal with a law enforcement agency of a large U.S. city for a combination of our solutions. With requirements for more comprehensive insights and a scalable deep packet inspection solution to meet visibility and security needs, the customer's teams determined. Our deployment for this customer utilizes the InfiniStreamNG data source, service assurance analytics provided by our nGeniusONE stack, as well as the network-based detection and response capabilities of our new Omnis Cyber Intelligence stack.
We are excited by this deal, particularly because it demonstrates how both network and security teams can leverage our scalable deep packet inspection technology to create a shared visibility platform, and we continue to see increasing customer interest in these types of use cases. Now turning to our go-to-market activities, importantly, we have continued to prioritize attending in-person events. We find these gatherings both effective and efficient, allowing us to demonstrate our solutions and engage with existing and prospective customers. For our second fiscal quarter, we plan to attend the Black Hat Conference, which takes place in Las Vegas and caters to the cybersecurity community. We also plan to attend VMware Explore, formerly known as VMworld, which takes place in San Francisco and is focused on enterprise digital transformation as well as cybersecurity.
At these events, we will demonstrate our NetScout and our customers are extending our visibility platform and underlying deep packet inspection technology into adjacent areas ranging from cybersecurity to adaptive DDoS. We will also showcase how our solutions are incorporating our Omnis AIF intelligence feed, solving remote work service assurance challenges to ROI of 201% over three years, effectively paying back the solutions cost in just seven months. We also were recently awarded the Intellyx Digital Innovator Award in the Enterprise-
Thank you, Michael, and good morning, everyone. I will review key metrics for our first- quarter of fiscal year 2023 and provide some additional commentary on our fiscal year 2023 outlook. Slide 12 details our first- quarter fiscal year 2023 results. During the quarter, total revenue grew 9.7% year-over-year to $208.8 million. Product revenue grew 19.9%, and service revenue grew 2.1%, both on a year-over-year basis. Our first quarter fiscal year 2023 growth profit margin was 74.5%, up 0.3 percentage points over the addition of approximately $15 million in radio- frequency propagation modeling projects, which had an average gross margin of less than 30%.
Quarterly operating expenses increased 9.7% year over year, primarily attributable to the return to a pre-pandemic environment, including more in-person sales and marketing events, as well as increased travel costs. We reported a net income of $8.4 million for the quarter, compared with $11.4 million in the same quarter last year. Diluted earnings per share was $0.24, compared with $0.20 in the same quarter last year, an increase of 20% year over year. Turning to slide 13, I'd now like to review key revenue trends by customer verticals and product lines. For the first quarter of fiscal year 2023, on a year-over-year basis, our service provider customer vertical revenue grew 26.9%, while our enterprise customer vertical revenue declined 4.8%. During the remaining 28%.
Turning to slide 14, which shows our geographic revenue mix. In the first quarter, our revenue was more concentrated than usual in the U.S. due to increased tier- one domestic carrier radio frequency propagation modeling project revenue. Also, two customers represented 10% or more of our total revenue in the quarter. Agreement to repurchase up to $150 million of our common stock. Through the accelerated share repurchase transaction, we received 70% of the estimated program shares upfront. Free cash flow for the quarter was negative $14.9 million. From a debt perspective, we ended the first quarter of fiscal year 2023 with $200 million outstanding on our $800 million revolving credit facility, which expires in July 2026.
To briefly recap our other balance sheet highlights, accounts receivable, net, was $112.9 million, a decrease of $35.3 million since March 31, 2022. The DSO (days sales outstanding) metric at the end of the first- quarter of fiscal year 2023 was 44 days versus 63 days at the end of the first quarter of fiscal year 2022 and 64 days at the end of our fiscal year 2022. Let's move to slide 16 for commentary on our outlook. We are reiterating our non-GAAP outlook for fiscal year 2023 that was presented during our May 5, 2022 fourth- quarter and full fiscal year earnings call.
As a reminder, for fiscal year 2023, we anticipate revenue in the range of $895 million to $920 million with single-digit top-line growth rate. The effective tax rate is anticipated to be in the range of 20% to 22% with the current rate at the upper end of that range. Assuming between 73 million and 74 million weighted average diluted shares outstanding, which includes the estimated impact of the $150 million accelerated share repurchase program with single-digit revenue and EPS growth rates on a year-over-year basis. That concludes my formal review of our financial results. Thank you, and I will now turn the call over to the operator for Q&A.
At this time, if you would like to ask a question, please press star one on your telephone keypad. If you wish to remove yourself from the queue, press pound key. We do ask in the interest of time that you.
You know, maybe expanding upon Anil's statement where he called out some timing of enterprise customer order shipments.
Matt, overall, I mean, I know there are a lot of anxiety about recession and what's going on. So far, luckily, we are not seeing results versus the yearly gets skewed because of large deals. At this point, we are not seeing any impact really on from what is the macroeconomic headwinds. As we see, I mean, we still feel good about the guidance range we have provided.
Great. Thanks. Helpful. Then, regarding security, just on the seasonality , it looks like your third quarter, the December calendar year quarter was seasonally strongest last year. Is that the type of cadence we should look for on security here, kind of that normal enterprise build through the year with the segment, or is there anything else to keep in mind around enterprise seasonality for security?
Yeah. As you pointed out, Dan, the second half of our year, either Q3 or Q4, is seasonally higher due to, you know, as the year progresses and we continue to see traction in Omnis, you might be able to see a little more of an impact in Q4 than in Q3.
Okay, great. Thank you.
Our next question comes from James Fish with Piper Sandler.
Hey, guys. Thanks for the questions. Jean, deferred revenue was down a bit more than normal this quarter. Looks like by about $40 million sequentially. Was this related to product backlog or something else? In the last few quarters, you actually gave us product backlog. Could you give us that this quarter, including across, I think you broke out core and radio frequency parts in the-
Propagation modeling that we started to execute on in this fiscal year, as well as generally just the timing of multiyear renewal orders, where we're very heavy in Q3 and Q4 and much lighter in Q1. The product backlog, as you recollect, was about $110 million at the end of last fiscal year, with about $60 million of that being calibration. So we used approximately $15 million this year, this quarter, I'm sorry. Of that, we would have about $45 million left of calibration revenue to go through the product revenue line item. The shippable backlog, which goes through product revenue also, we shipped the $50 million at the beginning of Q1, and then we built the backlog in that area back up to about $40 million.
Total backlog at the end of Q1 still sits around $85 million.
Okay, great. Appreciate that. Also appreciate that, security versus service assurance. I won't bug you on that question like I normally do, Jean.
Thank you.
On the radio- frequency side, you know, great quarter there, but how much longer of a tail do you guys expect the RFP business to have? We're starting to hear some of the core service assurance deployments. Is there any way to think about how you guys are getting the kinda gross margin on the year given the mix between RFP and the core service assurance? Thanks, guys.
As we move more and more towards software side, we can compensate for some of the. Our OpEx line is generally similar to the previous year, except for the travel expenses we talked about. We said this will be balanced out. When we gave the guidance on EPS and everything, it assumes most of the calibration, or all of it, I guess, Jean, to be shipped this year. That's all built into the numbers which we have provided for the guidance.
Yeah, just to add to that point, Jim, gross profit, you're correct, will be absorbing about $60 million of backlog at probably less to potentially slightly up from the full gross profit margin of last year.
Very helpful. Thanks, Anil. Thanks, Gene.
Yeah.
Thank you.
Our final question comes from Kevin Liu with K. Liu & Company. Your line's open.
Hi. Good morning, guys. Could you talk a little bit about just what the government pipeline looks for this quarter and if you-
Of projects, and some of them are funded or not funded. I would say on a year-over-year basis, given just the state of the U.S. government at this point in purchasing and their focus, similar to the Q2 of last year and maybe up from that percentage.
Got it. Just in terms of the second half outlook for service provider spending, it seems like in terms of service provider mix and whether you'll continue to see more kind of work on the propagation modeling side or if that starts to change either to more, you know, a traditional.
It's gonna be much less calibration and mostly service assurance orders and business in the second half. This quarter's year-over-year growth was driven somewhat by the backlog. We still have a lot of business in the pipeline with the service provider and the enterprise looks depressed. Overall, when we end the year, I think so. Basically, there is besides calibration and traditional service assurance, there are some other things happening with as people are getting the 5G spend, which has very similar margin profile as the general service assurance business versus last year.
All right. That's good to hear. I appreciate you taking my question.
Sure. Thanks.
There are no further questions at this time. I'll turn the call over to Tony for closing remarks.
Okay. Thank you, operator. Thank you everybody for joining us today. That concludes our call for the day. Have a good day. Thank you. Bye.