CHAKARAVRTHI JAPA

137^th PL NE | Redmond WA 98052 | chakrijapa@gmail.com

Phone +1 203 997 2445

 

Telecommunications Engineer

SUMMARY

·               6+  years of experience in the networking/wireless industry. Result oriented professional with a passion to build effective teams and to continuously exceed customer expectations.

·               Solid experience in building and managing specific solutions/technology/product consulting for both onshore and offshore

·               Planned and executed projects involving cross-functional teams and managed deliverables to/from partners, vendors and customers

·               Capture, track, analyse, and communicate requirement change requests, enhancements, and defects. Identify, clarify, and recommend solutions to issues and risks impeding progress.

·               Experience in review of Requirements document, Design documentation.

·               Solid command of SGSN/GGSN Gx, Sy and Sp Interfaces Familiar with 3GPP core protocol suite and the core data nodes: SGW/PGW/PCEF, PCRF GGSN, RADIUS, DHCP, DNS .

·               Expertise in SGSN/GGSN interface to EPC gateway Diameter and AAA Signaling expertise needed per existing infrastructure and call flows EPC Knowledge (3G, 4G, GGSN, SAEGW)

·               Extensively worked on Policy (PCRF)* Policy Control and Routing Function per 3GPP specification

·               Expertise on 3GPP standards related to PCRF and P-DRA platform, i.e. Gx, Sy, Sp interface

·               IR.94 Standard Video and PCRF treatment expertise per existing projects.

·               Extensive experience in design and development of IMS compliant component (P/S/I-CSCF,HSS) in IMS network architecture and services including RCS or VoLTE

·               Policy/charging and QoS enforcement in packet data networks.

·               Extensive experience in LTE / VOLTE network architecture and DIAMETER Base interface

·               Experience in Integrating modules, System, Regression and Performance testing.

·               Experience in automate  Unit test cases and System Integrate test case.

·               Resolve E2E network issues on EPC and VOLTE networks

·               Very good understanding of VOLTE/IMS/EPC call flow and SIP messages

·               Experience in  Analysing ALU and E/// network issues during Live debugging

·               Experience in Live debugging of E911, VOLTE, LTE, IMS issues Before deployment

·               Experience in  Analysing LTE, WCDMA, VOLTE log packets specifically to analyze LTE attach procedure, handovers, call drops, call failures

 

 

 

 

 

 

 

 

Career Experience:

 

AT&T Labs, Mobility Engineering & Development

Duration: January 2014 to Till date

 

Role: Packet Core Network Engineer

 

Provide technology leadership in the area of policy platform design, management, and integration, with specific emphasis in development and architecture of AT&T's DIAMETER-based Policy Access Server (PAS) and PCRF. Perform tactical decision-making in response to technical issues, guide test case development and execution, interface with platform vendor and peer AT&T teams on a regular basis, and contribute technical input to overall PAS design and lifecycle evolution.

 

Key Responsibilities:

 

·   Drive system design and platform engineering efforts for the ongoing development and lifecycle of the PAS platform.

•                               Extensive experience in  DIAMETER Base interface , DRA/DSR
•                               Implement solution for Gx, Rx Diameter interface
•                               Extensive Hands on experience on PCRF and PAS

·   Monitoring the performance and troubleshoot PAS and PCRF issues

·   Expert at Diameter and DRA functions

·   Contribute to architecture documentation (NDR, Gold Standards)

·   drive lab activities and submit change control documentation (Lab Engineering Plan, Engineering Design Plan); participate in vendor roadmap review

·   Contribute technical information in Feature Requests (FR) for new requirements sent to platform vendor; participate in RFPs with prospective future vendors

·   Drive various platform configuration changes via relevant documentation procedure (MOP, Implementation Guide, and Deployment Guide). Respond and react to production-related issues escalated from ATS and Operations on an as-needed basis

·   Technologies used  Distributed blade architecture (HP BladeCenter, Cisco UCS), Linux/UNIX operating systems, RADIUS/DIAMETER, TCP/UDP/SCTP, and  3GPP & LTE PGW, PCRF, PCEF, SPR, P-CSCF, and DRA

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

AT&T Labs, Mobility Engineering & Development

Duration: April 2012 to December 2013

 

 

Role: EPC Systems Integration and Testing coordinator

 

Responsibility includes Monitoring, upgrading and check the performance of SAEGW. Design of scenarios that would simulate failure of LTE UE stack in IOT and Field-testing. The testing was done during conformance testing thereby reducing the failures seen at IOT and Field Test levels. Scenarios included testing of inter-operability robustness between layers of LTE UE Protocol Stack, IRAT scenarios, collision, error and boundary conditions. Scenarios were also designed keeping in the mind the real-time usage by data users and failures occurring during it.

 

Key Responsibilities:

·   Worked on Revised-QOS,Alternate-QOS,Static-QOS,THP(Throttling Handling Priority) and FFA IPV6 Projects

·   Extensive hands on experience on ASR5K( upgrades, configuring and troubleshooting)

·   Monitor Subscriber information and packet drops in Inbound and Outbound Traffic on SAEGW

·   Responsible for checking data traffic and measuring the performance of  SIAD, MSN , and SAEGW during TCP/UDP Downlink and Uplink traffic under various RF conditions

·   Throughput testing carried out for static and mobility test cases, which include file transfer (Upload/Download) using IPERF

·   Working knowledge on LTE core system interfaces and protocols such as S1-MME, S1-U, S6a, S11, S5/S8,S1-AP, RRC, GTPv2c, and GTP-U

·   Developed test cases for various LTE features like Attach, Detach, Tracking Area Update, Service request, S1 release and IRAT  handover

·   Feature testing includes Handoffs, IRAT Handoffs, Call Forwarding and Call Conference

·   Extensive experience in IMS and LTE architecture, protocol structure ,Call Flow, Inter and Intra LTE Handover

·   Experience with performance analysis and troubleshooting various network issues

·   Responsible for developing test plans, interpreting product specifications, and debugging failures

·   Responsible for documenting failure scenarios and performing test as per customer requirement

·   Preparation of design documents for various scenarios in accordance with LTE 3GPP standard

·   Perform Pre and Post Implementation health checks for the SAEGW

·   Reviewed test cases and provided additions/changes. Presented various test cases/scenarios to the business teams for approval

·   Managing the tasks of testing mobile wireless technology by applying standard testing procedures

·   Testing in accordance with established procedures, maintaining a high standard of service delivery that ensures effective customer relations.

·   Applications used to perform test cases and analyse logs are JDSU, WIRESHARK, NETSCOUT, QXDM, IPERF server, Secure CRT, Microsoft Network Monitor, Ixia simulation tool and Citrix Receiver

·   Effective working knowledge on Quality Center database

Samsung ,Plano TX Duration: March 2010 to November 2011   Role: 4G LTE Core Systems Engineer
·   Troubleshoot and support issues with different network interface using Wireshark tool for S1-MME, S1-U, S6a, S2a, S6b, SGi, S11, Gx, and Gy. ·   Capturing and analysing traces to troubleshoot different protocols such as S1AP, Diameter, GTP-C, GTP-U etc. on their respective interfaces. ·   Analyse and maintain network performance on daily basis, which includes monitoring health for EPC elements and interfaces. ·   Perform software upgrade with pre/post health checks on EPC nodes MME, SGW and PGW ·   Creating MOP for various upcoming projects and performs verification process in lab before its release. ·   Support FIT activity which includes co-ordinating with other network element engineers along with field technicians ·   Troubleshoot with RAN, Backhaul, PCRF, OCS teams for any issues pertaining to TDD, FDD sites, Policy functionality or billing issues. ·   eNB verification for FDD and TDD sites on Core elements ·   Executed test cases in Sprint’s project for pre and post paid customers which includes working with filters, policies on PGW and PCRF with support of SPS and OCS teams. ·   Work with 3G core/ran team for issues related to hand up-down procedure for eCSFB call or eHRPD. ·   Design and implement Pico cells in EPC that includes creating routes in MME and SAEGW with regards to indoor events require addition radio support.

 

 

 

 

 

 

Ericsson Australia

Duration: March 2009 to January 2010

 

Role: Integration/Test (UMTS/LTE)

 

Responsibilities include debugging of failures in IOT and Field Test of the LTE UE Stack. Failures need to be root-caused to the right sub-component. Responsibility includes interacting with development and test teams to ensure critical blocking bugs are resolved avoiding delay in issues resolution by routing to proper sub-components of UE.

 

Key Responsibilities:

§    Responsible for End to End Testing

§    Involved in writing Test cases for Default bearer, dedicated bearer establishment, modification and deletion

§    Worked on creating Test cases for MME interoperability with S-GW

§    Performed protocol conformance testing for GTP-C/GTP-U

§    Involved in Lab setup ,S-GW/P-GW configuration and troubleshooting

§    Performed blade redundancy check ( Active and standby Test ) ,High availability and  Load balance Test ,Traffic switchover to standby blade

§    Fault / Alarm Management for the latest 3G network of Telstra (RBS3206 and EDGE enabled RBS2206/2202)

§    Performed Pre and Post Implementation health checks for the RNC re-parenting work such as NodeB and RNC

§    Executing call processing (CS and PS) test cases , Inter-system (UMTS to LTE) handovers, capturing & interpretation of call traces gained during testing and reporting the test results

§    Responsible for measuring KPI’s when performing throughput test

§    Analysis of issues related to low data throughput.

§    Monitoring the 3G alarms, working closely with the technicians on site, guiding them what work needs to be done and checking that the site is up and running when the work has been completed.

§    Provide test environment that will support the project testing, including commissioning and activating network and IP links

§    Providing technical troubleshooting assistance, problem analysis and diagnosis, through to fault resolution.

§    Performed consistency check and implemented RBS and RNC baseline auditing for newly integrated sites.

§    Performed pre and post checks on all the nodes to avoid any sort of discrepancies.

§    Performed weekly monitoring of relevant network element

§    Prepare weekly reporting packs with capacity data using Business Objects.

§    Organizing drive tests for the technicians to check the signal strength for a fault reported location

§    Create TTA (Trouble ticket Administration) Tickets/ Work Orders and pass them on to support groups for fault restoration.

§    Create Customer Operation Network Event Notification (CONEN) within the defined targets.

§    Ensure fault resolution is within the negotiated service level agreements(SLA)

§    Application used to perform test cases UE simulator,Wireshark

 

Academic Qualifications

§    Master of Information Technology, University of Ballarat, Sydney, Australia                                            2006

§    Bachelor of Computer Applications  Osmania University, Andhra Pradesh  India                            2003             

Professional Development and Certifications                                                                                                                                                                                          

§    CCNP  Cisco Certified Network Professional

§    CCNA  Cisco Certified Network Associate                                                                                        

Systems & Applications

§    Advanced capability using JDSU, WIRESHARK, QXDM, NETSCOUT, IPERF server, Secure CRT, Microsoft Network Monitor, Citrix Receiver, Ixia Simulation Tool Network General Sniffer and Iris Session Analyser.

§    Highly proficient user of commercial applications Microsoft Office Suite, Adobe and Internet