Skip to content

This is the multi-page printable view of this section. .

Return to the regular view of this page.

Egress and network paths

Internet transfer, cross-AZ traffic, NAT processing, free allowances, CDN paths, fixed bandwidth, and the per-GB versus port break-even.
Important

Snapshot: 2026-08-22. Network prices vary by region, path, direction, tier, and contract. A public transit port is not service-equivalent to cloud egress; the comparison exposes the different cost curves.

Direct answer

Network is its own bill, not an attachment to compute or storage. The same byte can be free on ingress, charged twice across an availability-zone round trip, processed by NAT, and charged again on internet egress.

network bill=∑(bytes×path rate)+hourly gateways+processing+ports and IPs \begin{aligned} \text{network bill} ={}& \sum(\text{bytes} \times \text{path rate}) \\ &+ \text{hourly gateways} + \text{processing} + \text{ports and IPs} \end{aligned}

Draw the path before applying a rate.

Current reference paths

Provider / service Path Snapshot rate
AWS aggregate services First internet egress allowance 100 GB/month free outside China/GovCloud
AWS aggregate services Next 10 TB internet egress $0.09/GB (¥0.610/GB)
AWS EC2/RDS Same-region cross-AZ commonly $0.01/GB each direction
AWS NAT Gateway Processing $0.045/GB + $0.045/hour reference
AWS public IPv4 Address $0.005/hour
Alibaba ECS Hangzhou Internet egress by traffic ¥0.80/GB
Alibaba OSS Busy / off-peak internet egress ¥0.50 / ¥0.25 per GB
Alibaba OSS CDN origin egress ¥0.15/GB
Alibaba cross-AZ NAT Processing CU ¥0.23/GB-equivalent + ¥0.23/hour

AWS aggregates egress tiers across many services and regions; eligibility and exceptions matter. Alibaba same-region VPC product communication is often free, but NAT, CEN, EIP, load balancers, cross-region links, and public paths introduce their own meters.

Fixed bandwidth versus per GB

The self-transit scenario uses a public 1 Gbps line at ¥12,500/month and a conservative practical load of 100 TB/month—about 30% of theoretical line rate. This is a procurement anchor, not a universal market price.

Monthly egress Required 1G ports Port cost Effective port ¥/GB AWS $0.09 Alibaba ECS ¥0.8 Alibaba OSS busy ¥0.5
10 TB 1 ¥12,500 ¥1.250 ¥6,104 ¥8,000 ¥5,000
20 TB 1 ¥12,500 ¥0.625 ¥12,207 ¥16,000 ¥10,000
25 TB 1 ¥12,500 ¥0.500 ¥15,259 ¥20,000 ¥12,500
50 TB 1 ¥12,500 ¥0.250 ¥30,518 ¥40,000 ¥25,000
100 TB 1 ¥12,500 ¥0.125 ¥61,035 ¥80,000 ¥50,000
500 TB 5 ¥62,500 ¥0.125 ¥305,177 ¥400,000 ¥250,000

Break-even volume is:

Vbreak=port monthly pricecloud egress price per GB V_{break} = \frac{\text{port monthly price}}{\text{cloud egress price per GB}}
Comparison Material crossing
AWS $0.09/GB ~20.5 TB/month
Alibaba ECS ¥0.8/GB ~15.6 TB/month
Alibaba OSS busy ¥0.5/GB 25 TB/month

The cloud curve starts at zero and scales with bytes. The port curve starts with a fixed step and then has near-zero marginal bytes until the next port. Bursty, uncertain, global, or DDoS-exposed traffic may justify the cloud/CDN premium; stable bulk transfer crosses early.

Alibaba fixed public bandwidth

The public Hangzhou example prices 1 Mbps fixed bandwidth around ¥23/month versus ¥0.8/GB by traffic. They cross at 23 / 0.8 = 28.75 GB/month. One Mbps can theoretically deliver about 328.5 GB/month, so fixed bandwidth becomes cheaper at roughly 8.8% utilization. Peak entitlement and service quality remain different from a by-traffic peak cap.

Architecture consequences

  • Use an S3 Gateway Endpoint instead of routing S3 traffic through AWS NAT when applicable.
  • Avoid accidental cross-AZ round trips for chatty application/database paths.
  • Price ECS, OSS busy/off-peak, and CDN-origin delivery as separate exits.
  • Keep stable origin and backup capacity on fixed or private paths; keep global edge, CDN, DDoS, and volatile traffic on statistically pooled services.
  • Track IPv4, idle NAT, orphan load balancers, and cross-region replication as first-class meters.

Exit capability

Provider exit waivers can materially change C1, but only when eligibility, covered services, destination, notice, transfer window, and approval process are documented. A negotiated or conditional waiver is recorded separately from the default meter. The operational export path and time limit remain part of the test even when the rate is zero.

Historical insight

AWS marginal egress fell from $0.20/GB in 2006 to $0.09 in 2014, then remained flat through the snapshot. Alibaba ECS Hangzhou stayed at ¥0.8/GB across the report’s 2016–2026 anchors. Silicon and disk gains do not automatically flow into the network meter. See Cloud price history.

Boundaries

  • Port procurement lacks the cloud platform’s global backbone, elasticity, routing, DDoS, operations, and zero-startup option.
  • The 1 Gbps quote and 100 TB practical load are scenario inputs.
  • Taxes, installation, private contracts, and regional fees can move crossings.
  • All rates must be refreshed after the snapshot before procurement.

Data and sources