we derived 93 % , 95 % and 92 % of our revenue from direct sales to customers for 2015 , 2014 and 2013 , respectively . we expect to continue generating a substantial majority of our revenue from direct sales in the future . we are headquartered in sunnyvale , california , with employees located throughout the americas , europe and the asia pacific region . we expect to continue to add personnel in the united states and 36 internationally to develop our products , provide additional sales support for key market verticals and emerging geographic regions , and invest in personnel to allow our business to scale to support our expanded business opportunities . 2015 financial and business performance we continued our transformation to a multi-market company in 2015 by adding metro and dci to our core long-haul business . we grew total revenue by 33 % compared to 2014 including revenue from transmode in the post-acquisition period . organically , excluding the partial year of transmode revenues , our revenues grew in the mid-20 % range in 2015 , marking the third consecutive year we have grown significantly faster than the overall wdm market . we also continued to expand our gross margin and operating margin in 2015 , demonstrating the leverage we have achieved from our vertical integration , the value proposition of our intelligent transport network and our commitment to prudent expense management . two customers each accounted for over 10 % of our revenue in 2015. these two customers accounted for 17 % and 13 % , respectively , of our revenue in 2015. one customer accounted for over 10 % of our revenue in 2014. revenue from this customer accounted for 19 % of our revenue in 2014. no individual customer accounted for over 10 % of our revenue in 2013. future business and industry trends across the broader market , we believe we have good opportunity to increase revenue in 2016 based on driving the growth of cloud xpress , achieving traction from new products , the inclusion of a full year of transmode revenues including cross-selling synergies , and capacity adds to our 100g footprint in the long-haul market . our focus on revenue growth will be complemented with continued efforts to drive cost improvements across all of our products and services . with respect to operating expenses , we will need to increase our investment levels in the short-term to more closely align with our growing market opportunity across long-haul , metro and dci . we have not scaled our operating expenses at the same rate as our revenue growth over the past several years as our revenue growth has exceeded our expectations . over a longer period of time , we believe that with sustained revenue growth , we can further leverage our vertically-integrated manufacturing model , which combined with the introduction of additional purpose built products , the ability to continue to sell incremental bandwidth capacity into deployed networks and expense management , can result in improved profitability and cash flow . our goal is to be the preeminent provider of optical transport networking systems to service providers around the world . our revenue growth will depend on the continued acceptance of our products , growth of communications traffic and the proliferation of next-generation bandwidth-intensive services , which are expected to drive the need for increased levels of bandwidth . our near-term quarter-over-quarter revenue may likely be volatile and may be impacted by several factors including general economic and market conditions , time-to-market development and market acceptance of new products , acquisitions of new customers and the timing of large product deployments . 37 results of operations revenue the following table sets forth , for periods presented , certain consolidated statements of operations information ( in thousands , except percentages ) : replace_table_token_3_th replace_table_token_4_th 2015 compared to 2014. product revenue increased by $ 197.0 million , or 34 % , in 2015 from 2014. the increase was primarily driven by continued momentum associated with the infinera dtn-x platform through both new network builds and capacity adds to existing networks . additionally , we benefited from the inclusion of revenue from transmode 's metro products since the acquisition , which occurred during the third quarter of 2015. in 2015 , we also experienced significant growth in revenue associated with our cloud xpress platform , which was introduced during the fourth quarter of 2014. these increases were partially offset by a reduction in sales of the dtn platform , reflecting the continued shift to 100gbps network deployments . services revenue increased by $ 21.7 million , or 23 % , in 2015 from 2014. the increase was primarily due to higher on-going support services as we continued to grow our installed base . additionally , during 2015 , we experienced higher levels of deployment services as customers built new networks utilizing our teams ' expertise . our services revenue also benefited from the inclusion of transmode 's services revenue since the acquisition . 2014 compared to 2013. total product revenue increased by $ 106.9 million , or 23 % , in 2014 from 2013. this increase was primarily driven by the continued strong market adoption of the infinera dtn-x platform as our customers continued to deploy our products to meet the growing bandwidth needs of their networks . the 38 increase in infinera dtn-x platform revenue was partially offset by a reduction in sales of the infinera dtn platform . services revenue increased by $ 17.1 million , or 22 % , in 2014 from 2013 due to higher levels of deployment services as customers built new networks utilizing our teams ' expertise as well as higher on-going support services as we continued to grow our installed base . story_separator_special_tag as of december 26 , 2015 , we had determined that while ownership changes had occurred in the past , the resulting limitations were not significant enough to impact the utilization of the tax attributes against our taxable profits earned to date . in determining future taxable income , we make assumptions to forecast federal , state and international operating income , the reversal of temporary differences , and the implementation of any feasible and prudent tax planning strategies . the assumptions require significant judgment regarding the forecasts of future taxable income , and are consistent with our income forecasts used to manage our business . 43 liquidity and capital resources replace_table_token_11_th replace_table_token_12_th cash , cash equivalents and short-term investments consist of highly-liquid investments in certificates of deposits , money market funds , commercial paper , corporate bonds and u.s. treasuries . long-term investments primarily consist of corporate bonds . the restricted cash balance amounts are primarily pledged as collateral for certain stand-by and commercial letters of credit related to customer proposal guarantees , value added tax licenses and property leases . operating activities story_separator_special_tag expect the notes will be converted in the short-term . upon conversion , it is our intention to pay cash equal to the lesser of the aggregate principal amount or the conversion value of the notes . for any remaining conversion obligation , we intend to pay cash , shares of common stock or a combination of cash and shares of common stock , at our election . as of december 26 , 2015 , long-term debt , net , was $ 125.4 million as of december 26 , 2015 , which represents the liability component of the $ 150.0 million principal balance , net of $ 24.6 million debt discount . the debt discount is currently being 45 amortized over the remaining term until maturity of the notes on june 1 , 2018. any future redemption or conversion of the notes could impact the timing of the repayment of these notes . as of december 26 , 2015 , contractual obligations related to the notes are payments of $ 2.6 million due each year from 2016 through 2017 and $ 151.3 million due in 2018. these amounts represent principal and interest cash payments over the term of the notes . any future redemption or conversion of the notes could impact the amount or timing of our cash payments . for more information regarding the notes , see note 11 , “ convertible senior notes , ” to the notes to consolidated financial statements . as of december 26 , 2015 , we had $ 274.7 million of cash , cash equivalents and short-term investments , including $ 57.6 million of cash and cash equivalents held by our foreign subsidiaries . our cash in foreign locations is used for operational and investing activities in those locations , and we do not currently have the need or the intent to repatriate those funds to the united states . our policy with respect to undistributed foreign subsidiaries ' earnings is to consider those earnings to be indefinitely reinvested . if we were to repatriate these funds , we would be required to pay u.s. taxes on such amounts , however , due to our significant net operating loss carryforward position for both federal and state tax purposes , as well as the full valuation allowance provided against our u.s. and state net deferred tax assets , we would currently be able to offset any such tax obligations in their entirety . however , foreign withholding taxes may be applicable . contractual obligations the following is a summary of our contractual obligations as of december 26 , 2015 : replace_table_token_13_th ( 1 ) we have service agreements with our major production suppliers under which we are committed to purchase certain parts . ( 2 ) we lease facilities under non-cancelable operating lease agreements . these leases have varying terms , predominantly no longer than ten years each and contain leasehold improvement incentives , rent holidays and escalation clauses that range from one to 10 years . in addition , some of these leases have renewal options for up to five years . we also have contractual commitments to remove leasehold improvements and return certain properties to a specified condition when the leases terminate . at the inception of a lease with such conditions , we record an asset retirement obligation liability and a corresponding capital asset in an amount equal to the estimated fair value of the obligation . leasehold improvements are amortized using the straight-line method over the shorter of the lease term or estimated useful life of the asset . an assumption of lease renewal where a renewal option exists is used only when the renewal has been determined to be reasonably assured . the estimated useful life of leasehold improvements is one to ten years . ( 3 ) tax liabilities of $ 2.9 million related to uncertain tax positions are not included in the table because we are unable to determine the timing of settlement if any , of these future payments with a reasonably reliable estimate . we had $ 5.2 million of standby letters of credit outstanding as of december 26 , 2015. these consisted of $ 3.1 million related to a customer proposal guarantee , $ 1.2 million related to a value added tax license and $ 0.9 million related to property leases . we had $ 5.0 million of standby letters of credit outstanding as of december 27 , 2014. these consisted of $ 3.0 million related to a value added tax license , $ 1.3 million related to a customer proposal guarantee and $ 0.7 million related to property leases . 46 off-balance sheet arrangements as of december 26 , 2015 , we did not have any relationships with unconsolidated entities or financial partnerships , such as entities often referred to as structured finance or special purpose entities ,

net cash provided by operating activities was $ 133.2 million for 2015 , $ 36.0 million for 2014 and $ 35.2 million for 2013. net income for 2015 was $ 51.0 million , which included non-cash charges of $ 80.1 million , compared to a net income of $ 13.7 million for 2014 , which included non-cash charges of $ 66.5 million . net loss for 2013 was $ 32.1 million , which included non-cash charges of $ 62.3 million . net cash provided by working capital was $ 2.1 million for 2015. accounts receivables increased by $ 16.0 million primarily due to the timing of invoicing in the period and inventory levels increased by $ 17.1 million to support the higher expected demand including multiple new products . accounts payable increased by $ 19.2 million primarily reflecting the volume of the business and timing of payments during the period . accrued warranty increased by $ 10.8 million due to general warranty reserves , the incremental cost to support the increased installed base and higher repair costs . net cash used to fund working capital was $ 44.2 million for 2014. accounts receivables increased by $ 54.0 million primarily due to higher revenue levels and the timing of invoicing of network deployments and collections during the period . inventory levels increased by $ 25.5 million to support the higher expected demand . accounts payable increased by $ 18.8 million primarily reflecting increased inventory purchases and timing of payments during the period . accrued liabilities increased by $ 11.9 million primarily reflecting higher levels of compensation related accruals . 44 investing activities net cash used in investing activities for 2015 was $ 91.5 million . investing activities during 2015 i ncluded the payment of $ 144.4 million in connection with the acquisition of transmode and net proceeds of $ 93.8 million associated with purchases , maturities and sales of investments during the year as we rearranged our portfolio to fund the acquisition .


 Write a concise suspicious activity report of the following text delimited by triple backquotes. Return your response as a formal report which covers the key points highlighting the location,dates,entity names and account holder information in chronological order of the text.
     ```net cash provided by operating activities was $ 133.2 million for 2015 , $ 36.0 million for 2014 and $ 35.2 million for 2013. net income for 2015 was $ 51.0 million , which included non-cash charges of $ 80.1 million , compared to a net income of $ 13.7 million for 2014 , which included non-cash charges of $ 66.5 million . net loss for 2013 was $ 32.1 million , which included non-cash charges of $ 62.3 million . net cash provided by working capital was $ 2.1 million for 2015. accounts receivables increased by $ 16.0 million primarily due to the timing of invoicing in the period and inventory levels increased by $ 17.1 million to support the higher expected demand including multiple new products . accounts payable increased by $ 19.2 million primarily reflecting the volume of the business and timing of payments during the period . accrued warranty increased by $ 10.8 million due to general warranty reserves , the incremental cost to support the increased installed base and higher repair costs . net cash used to fund working capital was $ 44.2 million for 2014. accounts receivables increased by $ 54.0 million primarily due to higher revenue levels and the timing of invoicing of network deployments and collections during the period . inventory levels increased by $ 25.5 million to support the higher expected demand . accounts payable increased by $ 18.8 million primarily reflecting increased inventory purchases and timing of payments during the period . accrued liabilities increased by $ 11.9 million primarily reflecting higher levels of compensation related accruals . 44 investing activities net cash used in investing activities for 2015 was $ 91.5 million . investing activities during 2015 i ncluded the payment of $ 144.4 million in connection with the acquisition of transmode and net proceeds of $ 93.8 million associated with purchases , maturities and sales of investments during the year as we rearranged our portfolio to fund the acquisition .
```    
 Suspicious Activity Report : we derived 93 % , 95 % and 92 % of our revenue from direct sales to customers for 2015 , 2014 and 2013 , respectively . we expect to continue generating a substantial majority of our revenue from direct sales in the future . we are headquartered in sunnyvale , california , with employees located throughout the americas , europe and the asia pacific region . we expect to continue to add personnel in the united states and 36 internationally to develop our products , provide additional sales support for key market verticals and emerging geographic regions , and invest in personnel to allow our business to scale to support our expanded business opportunities . 2015 financial and business performance we continued our transformation to a multi-market company in 2015 by adding metro and dci to our core long-haul business . we grew total revenue by 33 % compared to 2014 including revenue from transmode in the post-acquisition period . organically , excluding the partial year of transmode revenues , our revenues grew in the mid-20 % range in 2015 , marking the third consecutive year we have grown significantly faster than the overall wdm market . we also continued to expand our gross margin and operating margin in 2015 , demonstrating the leverage we have achieved from our vertical integration , the value proposition of our intelligent transport network and our commitment to prudent expense management . two customers each accounted for over 10 % of our revenue in 2015. these two customers accounted for 17 % and 13 % , respectively , of our revenue in 2015. one customer accounted for over 10 % of our revenue in 2014. revenue from this customer accounted for 19 % of our revenue in 2014. no individual customer accounted for over 10 % of our revenue in 2013. future business and industry trends across the broader market , we believe we have good opportunity to increase revenue in 2016 based on driving the growth of cloud xpress , achieving traction from new products , the inclusion of a full year of transmode revenues including cross-selling synergies , and capacity adds to our 100g footprint in the long-haul market . our focus on revenue growth will be complemented with continued efforts to drive cost improvements across all of our products and services . with respect to operating expenses , we will need to increase our investment levels in the short-term to more closely align with our growing market opportunity across long-haul , metro and dci . we have not scaled our operating expenses at the same rate as our revenue growth over the past several years as our revenue growth has exceeded our expectations . over a longer period of time , we believe that with sustained revenue growth , we can further leverage our vertically-integrated manufacturing model , which combined with the introduction of additional purpose built products , the ability to continue to sell incremental bandwidth capacity into deployed networks and expense management , can result in improved profitability and cash flow . our goal is to be the preeminent provider of optical transport networking systems to service providers around the world . our revenue growth will depend on the continued acceptance of our products , growth of communications traffic and the proliferation of next-generation bandwidth-intensive services , which are expected to drive the need for increased levels of bandwidth . our near-term quarter-over-quarter revenue may likely be volatile and may be impacted by several factors including general economic and market conditions , time-to-market development and market acceptance of new products , acquisitions of new customers and the timing of large product deployments . 37 results of operations revenue the following table sets forth , for periods presented , certain consolidated statements of operations information ( in thousands , except percentages ) : replace_table_token_3_th replace_table_token_4_th 2015 compared to 2014. product revenue increased by $ 197.0 million , or 34 % , in 2015 from 2014. the increase was primarily driven by continued momentum associated with the infinera dtn-x platform through both new network builds and capacity adds to existing networks . additionally , we benefited from the inclusion of revenue from transmode 's metro products since the acquisition , which occurred during the third quarter of 2015. in 2015 , we also experienced significant growth in revenue associated with our cloud xpress platform , which was introduced during the fourth quarter of 2014. these increases were partially offset by a reduction in sales of the dtn platform , reflecting the continued shift to 100gbps network deployments . services revenue increased by $ 21.7 million , or 23 % , in 2015 from 2014. the increase was primarily due to higher on-going support services as we continued to grow our installed base . additionally , during 2015 , we experienced higher levels of deployment services as customers built new networks utilizing our teams ' expertise . our services revenue also benefited from the inclusion of transmode 's services revenue since the acquisition . 2014 compared to 2013. total product revenue increased by $ 106.9 million , or 23 % , in 2014 from 2013. this increase was primarily driven by the continued strong market adoption of the infinera dtn-x platform as our customers continued to deploy our products to meet the growing bandwidth needs of their networks . the 38 increase in infinera dtn-x platform revenue was partially offset by a reduction in sales of the infinera dtn platform . services revenue increased by $ 17.1 million , or 22 % , in 2014 from 2013 due to higher levels of deployment services as customers built new networks utilizing our teams ' expertise as well as higher on-going support services as we continued to grow our installed base . story_separator_special_tag as of december 26 , 2015 , we had determined that while ownership changes had occurred in the past , the resulting limitations were not significant enough to impact the utilization of the tax attributes against our taxable profits earned to date . in determining future taxable income , we make assumptions to forecast federal , state and international operating income , the reversal of temporary differences , and the implementation of any feasible and prudent tax planning strategies . the assumptions require significant judgment regarding the forecasts of future taxable income , and are consistent with our income forecasts used to manage our business . 43 liquidity and capital resources replace_table_token_11_th replace_table_token_12_th cash , cash equivalents and short-term investments consist of highly-liquid investments in certificates of deposits , money market funds , commercial paper , corporate bonds and u.s. treasuries . long-term investments primarily consist of corporate bonds . the restricted cash balance amounts are primarily pledged as collateral for certain stand-by and commercial letters of credit related to customer proposal guarantees , value added tax licenses and property leases . operating activities story_separator_special_tag expect the notes will be converted in the short-term . upon conversion , it is our intention to pay cash equal to the lesser of the aggregate principal amount or the conversion value of the notes . for any remaining conversion obligation , we intend to pay cash , shares of common stock or a combination of cash and shares of common stock , at our election . as of december 26 , 2015 , long-term debt , net , was $ 125.4 million as of december 26 , 2015 , which represents the liability component of the $ 150.0 million principal balance , net of $ 24.6 million debt discount . the debt discount is currently being 45 amortized over the remaining term until maturity of the notes on june 1 , 2018. any future redemption or conversion of the notes could impact the timing of the repayment of these notes . as of december 26 , 2015 , contractual obligations related to the notes are payments of $ 2.6 million due each year from 2016 through 2017 and $ 151.3 million due in 2018. these amounts represent principal and interest cash payments over the term of the notes . any future redemption or conversion of the notes could impact the amount or timing of our cash payments . for more information regarding the notes , see note 11 , “ convertible senior notes , ” to the notes to consolidated financial statements . as of december 26 , 2015 , we had $ 274.7 million of cash , cash equivalents and short-term investments , including $ 57.6 million of cash and cash equivalents held by our foreign subsidiaries . our cash in foreign locations is used for operational and investing activities in those locations , and we do not currently have the need or the intent to repatriate those funds to the united states . our policy with respect to undistributed foreign subsidiaries ' earnings is to consider those earnings to be indefinitely reinvested . if we were to repatriate these funds , we would be required to pay u.s. taxes on such amounts , however , due to our significant net operating loss carryforward position for both federal and state tax purposes , as well as the full valuation allowance provided against our u.s. and state net deferred tax assets , we would currently be able to offset any such tax obligations in their entirety . however , foreign withholding taxes may be applicable . contractual obligations the following is a summary of our contractual obligations as of december 26 , 2015 : replace_table_token_13_th ( 1 ) we have service agreements with our major production suppliers under which we are committed to purchase certain parts . ( 2 ) we lease facilities under non-cancelable operating lease agreements . these leases have varying terms , predominantly no longer than ten years each and contain leasehold improvement incentives , rent holidays and escalation clauses that range from one to 10 years . in addition , some of these leases have renewal options for up to five years . we also have contractual commitments to remove leasehold improvements and return certain properties to a specified condition when the leases terminate . at the inception of a lease with such conditions , we record an asset retirement obligation liability and a corresponding capital asset in an amount equal to the estimated fair value of the obligation . leasehold improvements are amortized using the straight-line method over the shorter of the lease term or estimated useful life of the asset . an assumption of lease renewal where a renewal option exists is used only when the renewal has been determined to be reasonably assured . the estimated useful life of leasehold improvements is one to ten years . ( 3 ) tax liabilities of $ 2.9 million related to uncertain tax positions are not included in the table because we are unable to determine the timing of settlement if any , of these future payments with a reasonably reliable estimate . we had $ 5.2 million of standby letters of credit outstanding as of december 26 , 2015. these consisted of $ 3.1 million related to a customer proposal guarantee , $ 1.2 million related to a value added tax license and $ 0.9 million related to property leases . we had $ 5.0 million of standby letters of credit outstanding as of december 27 , 2014. these consisted of $ 3.0 million related to a value added tax license , $ 1.3 million related to a customer proposal guarantee and $ 0.7 million related to property leases . 46 off-balance sheet arrangements as of december 26 , 2015 , we did not have any relationships with unconsolidated entities or financial partnerships , such as entities often referred to as structured finance or special purpose entities ,

