Understanding Network Infrastructure Costs
Critical Network Components
Modern web applications require sophisticated network infrastructure to deliver content efficiently, protect against attacks, and maintain availability. Key components include CDN (Content Delivery Network) to cache content globally, DDoS protection to shield against attacks, load balancers to distribute traffic, Web Application Firewalls to block malicious requests, and monitoring to track performance. These services often cost more than the compute infrastructure running the application. Understanding infrastructure costs helps you budget appropriately, make tradeoffs between protection and performance, and identify cost optimization opportunities as your application scales.
Cost Components
Data Transfer (Bandwidth): The largest cost. Cloud providers charge $0.085-$0.15 per GB egress (outbound). 1 TB = $85-$150. Video streaming can cost millions monthly. CDN reduces bandwidth costs 50-70% by caching content geographically.
CDN (Content Delivery Network): Routes traffic through global nodes; caches static content. Costs $0.02-$0.10 per GB depending on provider (Cloudflare, AWS CloudFront, Akamai). Essential for video/media; worthwhile if bandwidth >100 GB/month.
DDoS Protection: Detects and filters malicious traffic. Basic: $200-$500/month. Advanced (100+ Gbps): $2,000-$5,000/month. Enterprise: custom pricing. Critical for attack-prone services (payments, government, finance).
Load Balancing: Distributes traffic across servers. $15-$50/month per load balancer. Multi-region load balancing: $100-$500/month. Necessary for high availability.
WAF (Web Application Firewall): Filters attacks (SQL injection, XSS, etc.). $100-$300/month. Essential for applications handling sensitive data.
Monitoring & Analytics: Traffic analysis, performance monitoring. $50-$500/month depending on scale and detail. Critical for troubleshooting and optimization.
Typical Network Costs by Scale
| Application Type | Monthly Bandwidth | Network Costs | % of Total Infrastructure |
|---|---|---|---|
| Blog/Small Site | 10-50 GB | $50-$200 | 20-30% |
| SaaS App | 500-5,000 GB | $500-$3,000 | 30-40% |
| E-Commerce (medium) | 5-50 TB | $2,000-$15,000 | 40-50% |
| Video Streaming | 100+ TB | $10,000-$100,000+ | 50-70% |
| Large Social Platform | Petabytes+ | $500,000+ | 40-50% |
Worked Example: E-Commerce Site, 50TB/month
Scenario: Growing e-commerce with 50 TB/month bandwidth, 5,000 peak requests/sec, multi-region deployment, full protection.
COSTS:
- Raw bandwidth ($0.10/GB): 50,000 GB × $0.10 = $5,000
- CDN (70% reduction): 15,000 GB × $0.05 = $750
- DDoS Advanced (100 Gbps): $3,000
- Load Balancing (multi-region): $300
- WAF: $200
- Monitoring: $300
- Total: $9,550/month
- Annual: $114,600
Without CDN: $5,750/month. With CDN: $1,750/month. CDN saves $50K annually for this scale.
Cost Optimization Strategies
1. Use CDN Aggressively: Cache everything possible. Even aggressive CDN use (90%+ hit rate) saves 60-80% on bandwidth costs.
2. Compress Data: GZIP compression reduces bandwidth 70-90% with negligible CPU overhead. Essential for JSON APIs.
3. Implement Caching Headers: Browser/edge caching eliminates repeat requests; reduces bandwidth 30-50%.
4. Monitor Anomalies: Unexpected bandwidth spikes indicate attacks, bugs, or abuse. Early detection saves thousands.
5. Negotiate Volume Discounts: Major providers negotiate 20-40% discounts for committed volumes.
6. Right-Size Redundancy: Dual-region for high-availability; single region for acceptable downtime; multi-region only if critical.
Important Limitations & Assumptions
- Costs are estimates based on typical 2024 pricing; actual rates vary by provider and negotiation.
- Does not include compute/storage costs (separate); this is network infrastructure only.
- CDN hit ratios assumed 70-80%; your mileage varies based on content type and caching strategy.
- Peak traffic and sustained traffic have different implications; this assumes reasonable traffic distribution.
Summary
Network infrastructure costs often exceed compute costs for data-intensive applications. CDN, DDoS protection, and load balancing are essential for modern applications but add significant monthly expenses. Understanding these costs and optimizing bandwidth usage (CDN, compression, caching) are critical for managing cloud spending. For high-scale applications (video, SaaS, social), network infrastructure can represent 50%+ of infrastructure costs.