Senior systems and telecom engineer | C/C++, Rust, Linux networking | IMS, IPsec/XFRM | Performance and reliability

I have worked at C-DOT since 2013, building telecom software across IMS, SIP, Diameter and charging integration. My focus is understanding protocol behaviour, debugging failures across components, and making Linux services reliable under load.

• Linux networking and systems: C/C++, Rust, concurrency, network I/O, IPC and kernel interfaces, including IPsec/XFRM.
• Telecom integration: SIP/VoIP, IMS, Diameter and charging state machines; tracing call flows and handling peer failures.
• Performance and reliability: bounded queues, backpressure, timeout handling, profiling and reproducible tests.
• Systems security: memory safety, protocol input validation, Linux hardening and TLS configuration.

My public projects are separate from my professional deployment experience. I distinguish prototypes, lab measurements and tested behaviour from production claims.

• xfrm-async-sa — C userspace control of Linux IPsec SAs over NETLINK_XFRM. Compares synchronous installation with a windowed pipeline. The review and study guide add ACK-correlation, timeout and cleanup fixes with mock, sanitizer and real-kernel namespace tests. This is kernel-interface programming, not a kernel module or a full IPsec controller.
• ims-5gc-iwf — IMS Diameter to 5G Core service interworking in Rust, with a codec, routing, translation rules and integration tests. See the README for implemented scope and remaining work.
• linux-kernel-eventqueue — C kernel lab: a bounded misc-device queue with blocking I/O, poll and backpressure. Runtime VM validation remains pending.
• ro-camel-iwf — Rust IMSCAP charging prototype connecting TAS Diameter Ro semantics to CAMEL CAP v2. Includes a charging state machine and simulator; CAP wire transport and clustered HA remain unimplemented.
• sip-rtp-diagnostics — C capture-analysis lab with bounded PCAP parsing and RTP diagnostics. Initial scope is documented in the repository.
• ro-charging-fastpath — C Diameter Ro charging engine written twice (naive vs hash tables, session pool, zero-copy parsing); a differential test requires byte-identical answers. Lab benchmark only.
• imsmq-ha — C inter-process messaging over lock-free shared-memory rings, with heartbeat failover to a hot standby and exactly-once answers under SIGKILL.
• ecall-router — C emergency-call routing: serial LRF/RDF lookups compared with cell-based PSAP selection and location by reference. Synthetic tables.
• sip-cnf — small C SIP function built for Kubernetes: probes, metrics and graceful SIGTERM drain. Manifests validated but not yet run on a cluster.
• ims-regtest — C open-loop IMS registration load tester (digest auth, retransmissions, latency percentiles) with a verifying stub S-CSCF. No IMS-AKA.
• linux-hardening-audit and tls-audit — Python assessment tools with offline tests for Linux and TLS configuration rules.

Merged:

• rsipstack #142: typed Service-Route header (RFC 3608), with the route set retained from REGISTER.
• rsipstack #143: preload that route set as Route headers on out-of-dialog requests, with tests for ordering and default behaviour.

Open, under review:

• Kamailio #4937: registrar and IMS S-CSCF registrar validate every Contact URI in REGISTER (the first Contact header was skipped).
• Kamailio #4943: dialog module option to replicate the timeout-BYE flag over DMQ, for HA pairs.
• Kamailio #4945: P-CSCF IPsec module rejects a 401 without IK (it was checked as CK twice) and compares CK/IK by length instead of strcmp() on unterminated buffers.
• curl-rust #663: fix an i32 overflow in Multi::timeout_i32, with boundary tests.
• hampi #145: ASN.1 compiler skips deriving Eq for types containing REAL.
• aya #1716, #1717: corrected eBPF object parser docs.

I also explore tool-execution safety in agent-security-lab and small agent frameworks in Rust and Python. These are secondary experiments alongside my systems and telecom work.

IPC and IITD kernel assignments are older C coursework.

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