How VSI Helped a California Security Vendor Build a High-Performance URL Filtering Engine Fast with Its DPI SDK

A California-based network security product company needed to rapidly add URL filtering capabilities to strengthen its next-gen network protection suite. The feature was critical to their roadmap, investor commitments, and upcoming enterprise pilots. In-house development would have required building a deep packet inspection (DPI) pipeline from scratch — a 6–9 month effort involving kernel engineering, network protocol parsing, performance optimization, and QA cycles.

To meet their go-to-market deadline, the company partnered with VSI, leveraging its production-ready Deep Packet Inspection (DPI) SDK to dramatically accelerate development.

Business Challenge

The client faced three intertwined challenges:

1. Time-Critical Go-To-Market Pressure

They had a fixed enterprise pilot date with two Fortune-500 prospects. Missing it would delay their next funding round and weaken competitive positioning.

2. Engineering Bandwidth Constraints

Their team had strong application-level developers but no specialized kernel-level or packet-processing experts capable of building a DPI foundation internally.

3. High Performance Requirements

The URL filtering engine needed to operate at line rate, support HTTP/HTTPS, handle complex header extraction, and scale across Windows and Linux network agents.

Why the Client Chose VSI?

The client evaluated three alternatives:

• Licensing a full network security stack (too expensive and rigid)
• Building in-house (too slow)
• Partnering with a boutique security engineering firm (risk of long spin-up time)

VSI stood out because of:

1. A Ready-to-Integrate DPI SDK

VSI’s DPI SDK already provided:

• Controlled test HTTP/HTTPS traffic generation
• Packet capture and inspection pipeline
• Extractors for URLs, SNI, headers
• Built-in detection examples
• Clean API surface to plug into existing network agents

2. Expertise in Kernel-Level & Real-Time Network Engineering

VSI’s engineering team brought immediate execution capability without learning overhead.

3. Low Total Cost & High Speed of Integration

The client could start building product logic immediately instead of building foundations.

Solution Delivered

1. Integration of VSI’s DPI SDK into the Client’s Agent

VSI engineers integrated the SDK into the client’s existing network agent architecture within three weeks, enabling URL extraction for both HTTP and HTTPS traffic.

2. Custom URL Categorization Logic

Working closely with the client’s product team, VSI added:

• URL parsing & normalization
• Category mapping
• Policy check workflows
• Block/allow decision pipeline

3. Performance Optimization & QA Automation

VSI optimized packet path operations and built traffic-simulation scripts

4. Deployment-Ready Build & Documentation

Deliverables included:

• Fully integrated URL filtering engine
• Implementation documentation
• API guides
• Unit and integration test suite
• Benchmark data for investor and customer presentations

Impact: 6 Months Saved in Go-To-Market Timeline

Because VSI provided a pre-built DPI foundation, the client avoided:

• 3–4 months building packet capture and parsing
• 2–3 months building extraction logic and edge-case handling
• 1–2 months debugging performance and stability issues

Result:

The client accelerated their enterprise pilot by at least 6 months and secured early revenue opportunities that would otherwise have been delayed.

Additional measurable outcomes:

• 70% reduction in engineering effort
• Immediate readiness for enterprise POCs
• Reduced cost versus hiring kernel engineers in the U.S.
• Faster investor confidence, helping justify their subsequent funding milestone

Client Quote

“VSI’s DPI SDK eliminated months of foundational engineering work. Their team gave us a production-ready URL filtering engine in record time — easily one of the best technical partnerships we’ve had.”

Conclusion

By combining a ready-to-integrate DPI SDK with deep security engineering expertise, VSI enabled the client to compress a complex development effort into mere weeks. This strategic acceleration helped the company strengthen its product roadmap, win early enterprise pilots, and significantly improve time-to-market outcomes.

VSI continues to support the client as they expand into broader network threat-detection use cases — demonstrating the long-term value of an SDK-driven engineering partnership.