This trade runs on jargon, and not for show — nearly every term maps to money or to a trap. 95th-percentile billing (95计费) and daily-95 monthly-average (日95月平) differ by one convention, and that difference can move a month-end invoice by twenty or thirty percent. Get the cross-province ratio wrong and net settlement income flips from profit to loss. Fail to state transit fees (过点费) in a quote and a whole private line can net out to zero. We work in this vocabulary every day — scheduling traffic, negotiating settlement, chasing faults — so we have organized it into a quick-reference table. Terms are grouped by context, and the definitions stick as closely as we can to how carriers and resellers actually use them. The China-specific terms keep the original Chinese in parentheses.
Billing models
| Term | Definition |
|---|
| 95th-percentile billing (95计费) | Billed on the 95th percentile of the monthly bandwidth peak (dropping the top 5% of peak points); common for high-traffic services. |
| Daily-95 monthly-average (日95月平) | Take the daily 95th-percentile peak, then average those daily values over the month — cheaper than traditional 95th-percentile billing. |
| Flat-rate port (包端口) | A fixed-lease physical port (e.g. a 10G port), billed on port capacity rather than actual traffic. |
| Subsidized port (补贴端口) | A low-cost or free port a carrier offers to attract customers (usually requires a long-term commitment or a traffic threshold). |
| Paired port (配比端口) | A bundle pairing a primary and a backup port (e.g. 10G primary + 1G backup, or redundant primary/backup ports, or how many metro ports an IDC port is paired with, or how many free ports a billed IDC port is paired with). |
| Commission (酬金) | The sales rebate a carrier pays a reseller (e.g. cabinet commission, private-line commission, CDN resale order rebate). |
Resource types
| Term | Definition |
|---|
| Port-80 resource (80资源) | A server that supports HTTP port 80 (for ordinary web service). |
| Non-port-80 resource (非80资源) | A server that supports only non-80 ports (e.g. 443/8080); common for video, downloads, and similar. |
| Cloud-host resource (云主机资源) | A virtualization-based cloud compute host (elastic scaling, pay-as-you-go). Usually refers specifically to resources like Tianyi Cloud and China Mobile’s Big Cloud running PCDN on cloud hosts. |
| High-defense (高防) | A server with DDoS protection (defense capacity up to the Tbps range). |
| Origin (源站) | The original server for the business data (the node a CDN pulls content from). |
| Dark fiber (裸纤) | A pure physical fiber direct connection from the carrier (no protocol conversion, lowest latency). |
Network architecture
| Term | Definition |
|---|
| Metro network (城域网) | A carrier’s internet dedicated line. |
| BGP | Multi-line smart routing protocol (auto-selects the best path across the three networks: China Telecom / China Unicom / China Mobile). |
| Three-line (三线) | Simultaneous connection to all three carriers: Telecom + Unicom + Mobile. |
| Dual-line / multi-line (双线/多线) | Connection to two carriers (dual-line) or several (multi-line). |
| OTN | Optical transport network (provides the high-bandwidth, low-latency underlying fiber resources). |
| Three-line single-IP (三线单IP) | Three networks converged but sharing one IP (smart resolution via BGP, which actively advertises the IP), or advertised on your behalf via a carrier address. |
| Three-line triple-IP (三线三IP) | Independent IPs for the three networks (the user configures DNS scheduling themselves). |
CDN technology
| Term | Definition |
|---|
| CDN | Content delivery network: caches content to edge nodes to speed up user access. |
| PCDN | A P2P + CDN hybrid, aggregating home broadband to servers, or hooking a standalone router/box to run CDN. |
| ACDN | Running CDN for top-tier internet customers from physical machine clusters on high-bandwidth metro access, delivered as VMs, bare metal, or via a k8s API. |
| Federated CDN (融合CDN) | A scheduling platform that pools resources from multiple CDN vendors (auto-selects the best provider). |
| Three-network CDN (三网CDN) | A CDN service covering all three networks: Telecom / Unicom / Mobile. |
| Scheduling (调度) | Steering business traffic so the cheap ports run full and the expensive ports only reach the 95th percentile. |
| Peak-shaving scheduling (削峰调度) | Steering business traffic across nodes or ports to keep usage at the 95th percentile only. |
Testing and operations
| Term | Definition |
|---|
| Trial period (测试期) | The free trial stage after a resource is provisioned (typically 7–30 days). Some carriers allow repeated test windows, toggled by port batch. |
| Test server (测试机) | A server used to validate a service before it goes live. |
| Stress test (压测) | Load testing: simulate high concurrency to check whether the bandwidth is provisioned to the full amount. |
| Single-line test server (单线测试机) | A test server connected to a single carrier only (e.g. Telecom). |
| Three-line test server (三线测试机) | A test server connected to all three networks. |
| Traffic discrepancy (流量误差) | The difference between the carrier’s billed traffic and the user’s monitored traffic (the industry allows ±3%). |
| Traffic scraping (抠流量) | Reducing billed traffic by technical means (e.g. compression, deduplication). |
| Inverted traffic (流量倒挂) | Inbound traffic > outbound traffic (in CDN scenarios outbound is usually larger, so an inversion needs to be investigated as an anomaly). |
| Three-network test (三网测试) | Testing access quality across Telecom / Unicom / Mobile at the same time. |
Other trade slang
| Term | Definition |
|---|
| Off-net routing (跑异网) | Traffic crossing between carriers (e.g. a Telecom user hitting a Unicom server; quality may degrade). |
| 1024 | Bandwidth unit conversion: 1Gbps = 1024Mbps. |
| Three 1024s (3个1024) | Three rounds of 1024, i.e. 1Gbps = 1024Mbps = 1024×1024Kbps = 1024×1024×1024bps. |
| Tianyi Cloud CDN (天翼云CDN) | China Telecom’s CDN service. |
| Order-by-proxy (代下单) | Buying carrier resources through a reseller (common for companies without direct partnership qualifications). |
| IP filing (IP备案) | Binding a server IP to a filed (ICP-registered) domain (mandatory for domestic business in China). |
1. Network coverage and settlement
| Term | Definition |
|---|
| Cross-province (跨省) | Business traffic crossing a provincial administrative boundary (e.g. Beijing → Shanghai), incurring a cross-province settlement fee (inter-carrier settlement cost is high). |
| Cross-city (跨地市) | Traffic crossing cities within the same province, which also requires settlement. |
| Settle-out (结出) | A carrier sending traffic out to another carrier (a settlement fee is owed). |
| Settle-in (结入) | A carrier receiving traffic from another carrier (settlement revenue is earned). |
| Net settle-in (净结入) | Settle-in amount − settle-out amount (a positive value means a settlement profit). |
| Cross-province ratio (跨省比例) | The share of cross-province traffic in the business traffic (usually required to be ≤30% to control cost). |
2. Data-center facilities
| Term | Definition | Technical detail |
|---|
| DC tier (机房等级) | National standard GB50174 tiers:• Tier A: fault-tolerant (dual power feed + backup)• Tier B: redundant• Tier C: basic | Finance / government-enterprise must choose Tier A; web services can take Tier B. |
| Self-built DC (自有机房) | A data center the carrier builds and manages itself (e.g. China Mobile’s Southern Base). | High stability, fast resource allocation. |
| Partner DC (合作机房) | A resource pool built by a third party where the carrier leases cabinets. | Lower cost, flexible expansion. |
| PUE | Power usage effectiveness = total power / IT-equipment power (ideal ≈1.3). | PUE>1.8 is high energy use; Beijing/Shanghai/Guangzhou/Shenzhen require ≤1.4. |
| Cabinet power (机柜功率) | A single cabinet’s power supply capacity (standard 4–6kW, high-density up to 10–20kW). | GPU compute clusters need ≥10kW. |
| Air cooling (风冷) | Traditional air-conditioning cooling (for low-to-medium density cabinets). | Low cost, simple maintenance. |
| Liquid cooling (液冷) | Circulating-liquid cooling (for high-density scenarios like GPU servers; ~50% better cooling efficiency). | Standard in compute centers; can bring PUE below 1.1. |
| Cabinet-power separation (柜电分离) | Billing electricity and cabinet rent separately (avoids bundled markup). | A common cost-reduction model for large customers. |
| Cabinet tray (机柜托盘) | The sliding-rail support that holds servers (standard depth 42U/48U). | Affects server deployment density. |
3. Fiber and transport
| Term | Definition | Related concept |
|---|
| Out-fiber (出纤) | Fiber laid outward from the DC (the user buys it from the carrier). | Must specify fiber-core count and routing. |
| In-fiber (进纤) | Fiber resource coming into the DC (provided by the carrier). | Usually includes splicing and patching service. |
| Optical cross-connect box (光交箱) | The fiber cross-connect cabinet (the transfer point between outdoor lines and in-DC lines). | The core device for patch-fiber operations. |
| WDM (波分) | Wavelength-division multiplexing (multiple signals on a single fiber to raise bandwidth). | Mandatory on backbone networks; a single fiber can reach 192×100Gbps. |
| Backbone network (骨干网络) | The national/provincial core transport network (trunk bandwidth ≥100Gbps). | The three major carriers’ own topologies. |
| Backbone egress office (骨干出口局) | The backbone’s interconnection node in a city (e.g. Beijing Sanyuanqiao, Shanghai Nanhui). | Priority siting for multi-line BGP data centers. |
| Offshore egress (离岸出口) | A cross-border network egress (e.g. Hong Kong, Suifenhe nodes). | Common for filing-exempt business. |
| Dual routing (双路由) | A critical link configured with two physically separated paths (guards against a single point of failure). | Mandatory for finance / government-enterprise. |
4. Engineering and field ops
| Term | Definition | Operational notes |
|---|
| DC site survey (机房工勘) | On-site survey of the DC environment (load-bearing / power / cooling / cabling, etc.). | A required step before racking; produces a survey report. |
| Cutover (割接) | Migrating a service from an old system to a new one (often done in the small hours; must be filed). | A risky operation — keep a rollback plan ready. |
| Transit fee (过点费) | The relay fee for traffic passing through a third-party network node (e.g. if A→B must go via network C, you pay C). | A private-line quote must confirm whether the transit fee is included. |
| VM provisioning (配虚机) | Allocating a virtual test machine (temporary, for business validation). | Provided free during the trial period. |
| Billing term (T+2) (账期) | Last month’s fee is settled two months later (e.g. a March billing term is paid in May). | A common carrier settlement cycle. |
5. Streaming and compute
| Term | Definition | Technical logic |
|---|
| Pull stream (拉流) | The client pulls an audio/video stream from the server (e.g. what a live-stream viewer does). | The counterpart to “push stream” (the broadcaster’s side). |
| Compute (算力) | Data-processing capability (unit: TFLOPS/GPU card). | One A100 ≈20TFLOPS (FP32 precision). |
| Header coefficient (包头系数) | The ratio of IP/TCP headers to payload in network transport (usually ≈1.15–1.2). | Sizing bandwidth: actual bandwidth = business traffic × header coefficient. |
| Scheduling (调度) | Dynamically allocating resources (e.g. a CDN steering user requests to the best node). | Core algorithm: based on latency / load / cost. |
6. Ports and resource bundles
| Term | Definition | Cost strategy |
|---|
| Port bundle (端口组合) | A multi-port bundle (e.g. ten 10G IDC ports + five 10G metro ports). | Raises reliability, lowers backup cost. |
| Third-party DC (第三方机房) | A data center not self-built by a carrier (e.g. GDS, 21Vianet). | Large room to negotiate, but network quality depends on carrier access. |
