Experience

Palo Alto Networks

• United States
• Computer and Network Security
• 700 & Above Employee

• Principal Diagnostic Engineer

  • Oct 2020 - Present

  Sole Diagnostics Software developer for the SDWAN/Cellular line of products. Delivered diagnostics software to support 4 generations of product architectures consisting of over 15 SKUs in 2 1/2 years in this position. Joined the development team in the early conceptual stage of the first product design. Developed in C a light weight, highly functional, diagnostics execution state machine from scratch with emphasis on test portability and reusability. System also contains run time parameter settings and built in regression capability, making it ideal for all stages of diags in the product life cycle from power on bring up to environmental/edvt to manufacturing. Test development consisted of developing the driver access to all the devices on the system, develop the control path data access tests to all reachable devices and a traffic test infrastructure that utilizes Linux sockets to be able to create any packet format needed per the specific system and have a complete payload checking for all packets. Traffic infrastructure also contains a sequence checker, so if there are any missing packets, the specific packet/s that got lost were identified. Tough issues that I overcame: CPU NIC driver unintended behavior - MDIO access to second SFP not working. Uplink port dropped down from 10G to 1G when 1G SFP was installed in the system. Issue was due to a combination of NIC Ethernet driver and LEK FW functionality. Modified the NIC Ethernet driver to fix both issues. Vendor Ethernet Switch - Vendor convinced the team to use the new "Port Manager" configuration mode of the chip. Initial bringup of this Port Manager mode encountered numerous bugs with their SDK not working as intended. Worked with the Vendor to debug the issues found and implemented direct register access work arounds outside of the SDK APIs to get the switch working. Vendor PHY/Switch lock up during auto media switch. Isolated lock up behavior and implemented workaround from Vendor. Show less



Cisco

• United States
• Software Development
• 700 & Above Employee

• Diagnostic Engineer

  • Feb 2008 - Oct 2020

  Key diagnostics lead developer for High End Routing ASR-9K/NCS-6K platforms. Developed drivers and diagnostics for Cisco custom asic – Skybolt cross connect - to run on 3 different card types – RP, FC, LCs. Tests include access, interrupts, memory tests, BISTs, PRBS, traffic, environmental monitors (voltages, currents, temperatures), SI tuning. Developed drivers to support interface configurations at different data rates and forwarding algorithms. Integrated Avago AAPL SDK and lead debug sessions with Avago engineers to tune the Serdes interfaces for card to card connectivity across 4 different chassis/backplane types. As part of debug/tuning effort, developed auto tuning functions that used PRBS Bit Error Rates to find optimal SI parameter settings for all point to point connections across the backplanes. Timeline: 2017-2018 – initial development for the first generation Asics – LSP (NPU) and Skybolt on platform – consisting of Avago CM4 16nm technology. 2019-2020 – development for next generation Asics on linecards consisting of Avago Blackhawk 7nm technology on NPU. Bridged support for Avago Asic libraries and tuned and debugged the two technologies to operate together. Optical module driver – developed drivers for SFP10G, SFP28 (25G), QSFP28 (100G), QSFPDD (400G) modules based on Multi Source Agreement (MSA) specs as well as vendor specific proprietary specs. Show less



Redback Networks

• Computer Networking Products
• 1 - 100 Employee

• Diagnostic Engineer

  • Jan 2007 - Feb 2008



Cisco

• United States
• Software Development
• 700 & Above Employee

• Diagnostic Software Development

  • Apr 1994 - Dec 2006