Projects

·             Develop DSL Gateway with VoIMS capability.

·             Develop 4G/3G router for major US and European service provider with VoIMS/VoIP function.

Description:

Along with team, implemented router features for enterprise grade DSL and LTE routers.

Project Detail:

·          Implemented connection manager for LTE using Qualcomm QMI based interface and AT command, including control and status of the connection.

·          Managed implementation of SIP, MGCP & IMS stack, SLIC interface and implemented call manager.

·          Managed implementation of web GUI, 2.4G & 5G WiFi AP etc.

·          Managed implementation of open source VPN, IP Pass through, firewall, QoS, routing protocols, SNMP, TR069 etc.

·          Worked with Systems Engineer and Product Engineer to refine requirement and report status to upper management.

·          Worked with multiple QA team to insure through testing is done.

·          Worked with vendor such as Qualcomm and Lantiq to resolve integration issues.

Project

·             Develop and maintain SIP Call Controller for Tele-presence end point

·             Develop new features and maintain VoIP PBX

Description:

Implement and Maintain Tele-presence endpoint

Project Detail:

·          Maintain call features such as hold/resume, conference and presentation for Tele-presence video call.

·          Implement and modify to insure proper PBX functionalities such as call hunting, call forwarding etc.

Project

Development and Maintenance of SIP based DSL modem

Description:

Implement and Maintain VoIP functionality on DSL modem

Responsibilities:

·          Implement changes to comply with RFC-3261.

·          Implement proper handling of SIP error codes.

·          Verify and implement multi-line call features such as 3way calling and call transfer.

Project

Develop Video phone based on TI OMAP3530 chip

Description:

Design and Develop IP phone with LCD display

Responsibilities:

·        Researched technology such as VoIP chip set, open source SIP protocol stack and OS (i.e. Linux) etc. to provide solution for customer requirement.

·        Designed IP phone solution with LCD display using OMAP3530 evaluation board.

Project Title

·             Design and develop SIP Proxy features and maintain existing product

·             ISDN to SIP Gateway and FXS/FXO features

·             Integrate SIP Proxy with various softswitches.

Description:

Design and implement various SIP proxy features such as presence using SIP SUBSCRIBE/NOTIFY messages, message waiting etc., and call forking and shared line appearance.

Implement video capability in existing SIP proxy. Perform call admission control including bandwidth management and parsing and verification of video codecs in SDP.

Responsibilities: Develop Functional and Design specification for new features. Lead team to implement various features including:

·           Designed and implemented call admission control for video calls.

·           Performed bandwidth requirement analysis and bandwidth reservation for video calls.

·           Manipulated SDP based up on call admission control.

·           Participated in design of far end NAT traversing.

·           Designed and implemented SUBSCRIBE/NOTIFY message.

·          Designed and implemented SLIC driver for FXS/FXO ports. And feature specific to FXS ports such as distinctive ring.

·          Developed interface to DSP (TI320) to provide ring back, collect DTMF digits, packetize voice, echo cancellation, comfort noise etc.

·          Designed and implemented call controller to check for softswitch availability using SIP OPTION message and route calls to FXS port based up on dialing plan.

·         Performed special features such as Shared Line Appearance, call forking etc.

·           Fixed bugs to insure inter-operability with various softswitches.

Project Title

·               Designed and developed ESA call controller

·               Develop GR-303 to SIP/MGCP Gateway

Tools/Environment

C/C++, Linux, Hughes MGCP stack, GNU debugger

Description:

Develop MGCP Call Controller and emergency controller performs routing of internal calls running on Linux. Implemented feature to generate Call Detailed Record.

GR-303 to SIP/MGCP gateway terminates GR-303 calls on one side while initiates/terminates SIP or MGCP calls on other side. Call controller performs the routing and management of the call.

Responsibilities:

·                      Ported Hughes software MGCP stack.

·                      Design and developed call controller in C & C++.

·                      Integrated and tested with GenBand MGCP gateway and telecordia softswitch.

·                      Ported Hughes software MGCP stack and Trillium GR-303 (TMC) stack.

·                      Designed and developed call controller in C & C++ to perform call routing and call connection.

Project Title

MGCP to GR-303 gateway for VoDSL & VoCable

Tools/Environment

C, VxWorks, PowerPC, TI 320 DSP, Abacus load tester, Tornado 2.0, GNU Toolkit

Description:

MGCP to GR-303 gateway provides voice and data on a single DSL line using MGCP based protocol. Voice calls were terminated on class5 switch.

Responsibilities:

·                      Developed call controller module to support GR-303.

·                      Developed card redundancy and diagnostics and postmortem for debugging.

·                      Developed command line interface (CLI)

Embedded Operating systems

Linux, VxWorks

Languages

C, C++, Assembly

Test Equipment Used

CMW500, ethereal (wireshark), SIPp, openSIP, iperf, GNU debugger etc.

SIP devices & Softswitches

Asterisk, Broadsoft, Sylantro, MetaSwitch, Brekeke

Networking & VoIP Protocol

SIP, MGCP, H.323, ISDN, SS7, CAS, GR303, TCP/IP & ATM,

Tools

Software Development Methods

SVN, HP Quality Control, Clearcase, CVS, Perforce, DDTS, bugzilla, JIRA, MS project

Experience with Agile and Waterfall software development methodologies