15 Most Common Questions About Internet Leased Line (ILL)

Picture this: It is 4:00 PM on the last working day of the financial quarter. A mid-sized logistics firm in Cyber City, Gurugram is processing 1,200 urgent e-way bills while running video calls with overseas vendors. Suddenly, their high-speed fiber broadband drops. The local ISP support desk puts them on hold for 40 minutes, claiming a 'line cut down the street.' That 4-hour outage costs the company lakhs in delayed shipments and SLA penalties. It is precisely after an experience like this that IT heads stop relying on shared broadband and start evaluating an Internet Leased Line (ILL).

Switching to dedicated enterprise connectivity raises dozens of practical questions around delivery timelines, hidden costs, contract lock-ins, and SLA enforcement. Below are the 15 most common questions business leaders and network admins ask before signing an ILL contract, answered with complete operational transparency.

1. Delivery & Setup Questions

Q1: Exactly how long does installation take from PO to live connection?

For standard fiber-feasible enterprise locations across major Indian metro cities, the end-to-end delivery cycle takes 7 to 10 working days. The process starts with a physical site survey (completed within 24 hours), followed by fiber trenching or last-mile layout, CPE (Customer Premises Equipment) installation, testing, and final handover. If physical fiber laying requires local municipal permits (like MCG in Gurugram or BBMP in Bengaluru), delivery can extend to 14–21 days. In high-rise commercial parks with existing optical fiber infrastructure, activation can occur in under 4 days.

Q2: What happens if optical fiber cabling is not physically feasible at our office location?

If wired optical fiber last-mile is unavailable or delayed due to right-of-way (RoW) issues, an enterprise-grade radio frequency (RF) wireless connection is deployed as a temporary or permanent solution. RF connections deliver 1:1 symmetrical bandwidth over direct line-of-sight microwave links, backed by the exact same SLA commitments as fiber. Once physical fiber laying completes, the service transitions seamlessly to fiber without changing your public static IP addresses.

2. Bandwidth, Performance & Technical Specs

Q3: How is a 1:1 symmetrical leased line fundamentally different from 1 Gbps commercial broadband?

Commercial broadband (even high-speed 'FTTH' business plans) operates on a shared contention ratio, typically 1:10 or 1:20. That means your 300 Mbps broadband connection shares its local node capacity with dozens of neighboring offices. During peak hours, actual speeds drop drastically. Furthermore, broadband download and upload speeds are asymmetric—upload speeds are often throttled to 10–20% of download rates. An Internet Leased Line is 100% dedicated (1:1 contention) with identical download and upload capacity, meaning a 100 Mbps ILL delivers 100 Mbps continuously both ways regardless of neighborhood network traffic.

Q4: How many Public Static IP addresses are included with an ILL connection?

Every enterprise ILL circuit comes standard with a pool of IPv4 Public Static IPs (typically a /30 subnet providing 1 usable static IP or a /29 subnet providing 5 usable static IPs). These static IPs are essential for hosting on-premises ERP databases, configuring secure VPN tunnels, deploying IP-PBX platforms like Smartflo Cloud Telephony, running CCTV monitoring, and maintaining secure firewalls. Additional IPv4 subnets or IPv6 blocks can be allocated based on technical justification and APNIC guidelines.

Q5: What are the guaranteed latency and packet loss metrics?

Enterprise ILL connections are backed by rigorous performance metrics. Intra-city fiber latency is guaranteed under 10ms, national latency across major data center hubs (Delhi, Mumbai, Bengaluru, Hyderabad) remains under 30–40ms, and international latency to Singapore or Europe routed over subsea cables averages 60–120ms. Packet loss is SLA-committed at less than 0.1%, ensuring lag-free VoIP communications, real-time database syncs, and smooth video conferencing.

3. SLA, Reliability & Outage Management

Q6: What happens during a fiber cut or network outage?

Tata ILL features a dual-path fiber ring architecture in major enterprise zones. If a physical line cut occurs on the primary path, traffic instantly re-routes across the secondary path within milliseconds, ensuring zero service drop. If both paths fail, the 24x7 Network Operations Centre (NOC) detects the link down event automatically—often before your local IT team notices—and dispatches field engineers automatically.

Q7: How does the 99.9% uptime SLA financial credit system work?

The 99.9% Service Level Agreement allows a maximum total cumulative downtime of no more than 43 minutes in a calendar month. If service availability drops below this commitment due to provider-side issues, financial credits are directly adjusted against your next billing cycle. The credit formula calculates outage hours against the monthly recurring charge (MRC), guaranteeing accountability rather than empty service promises.

4. Pricing, Taxes & Contract Terms

Q8: What is the complete cost breakdown for an enterprise Leased Line?

An ILL bill consists of three components: Monthly Recurring Charge (MRC) based on speed, standard GST (18%), and a one-time installation charge (OTC), which is frequently waived on annual billing contracts. There are no hidden bandwidth cap fees or overage charges because data transfer is truly unlimited.

*Note: GST (18%) extra. Exact commercial quotes depend on physical location feasibility and contract tenure. Check detailed pricing options on our leased line pricing guide.

Q9: What is the standard lock-in period and contract commitment?

Standard enterprise ILL contracts carry an initial 12-month lock-in commitment. Multi-year agreements (24 or 36 months) often include discounted monthly rates and free managed router upgrades. Premature termination during the lock-in period requires paying out the balance of the remaining contract tenure, so selecting the correct initial bandwidth profile is crucial.

5. Upgrades, Scaling & Management

Q10: Can we upgrade bandwidth mid-contract if our company hires 50 new employees?

Yes. Bandwidth upgrades can be provisioned logically in under 2 to 4 hours without laying new fiber cabling, provided your physical access port is pre-provisioned for higher throughput. For example, if you install a 100 Mbps link on a 1 Gbps physical port, scaling to 200 Mbps or 500 Mbps requires simple software reconfiguration by the NOC, leaving your static IPs and firewall rules untouched.

Q11: Can we downgrade bandwidth if our team downsizes or moves to hybrid work?

Downgrades are generally permitted after completing the initial contract commitment period (typically 12 months). During the initial lock-in period, downgrades are restricted unless explicitly negotiated in special custom enterprise contracts.

Q12: Do we need to buy our own enterprise router or is Customer Premises Equipment (CPE) included?

You can choose between a Managed ILL model (where the ISP provides, manages, and monitors an enterprise-grade Cisco or Juniper router at your premises) or an Unmanaged model (where the ISP delivers an Ethernet handoff into your existing firewall or core switch). For multi-branch offices deploying software-defined networks, integrating SD-WAN iFLX on top of unmanaged handoffs provides intelligent application routing across multiple WAN links.

6. Operations, Portal & Shifting

Q13: How do network administrators monitor circuit bandwidth and usage in real-time?

Enterprise clients receive login credentials to a centralized self-service portal (Tata Tele iEnterprise Portal). The portal delivers real-time bandwidth utilization graphs, latency charts, historical traffic statistics, billing history, and immediate online ticket logging with direct escalation paths to network engineers.

Q14: What is the procedure if our office shifts to a new building or another city?

Network relocation is simple across 60+ covered cities in India. Submit a relocation request 15 to 20 days prior to your move date. A physical feasibility check is conducted at the new location. Once confirmed, the old circuit is deactivated while the new link is provisioned. If moving within the same telecom circle, static IP retention is frequently possible depending on network node routing.

Q15: Can an ILL link be paired with a backup broadband line for automatic redundancy?

Absolutly. Combining a primary 1:1 Internet Leased Line with a secondary cost-effective line creates high-availability infrastructure. Using an automated dual-WAN firewall or SD-WAN box ensures seamless automatic failover—if fiber maintenance occurs on the primary line, all active user traffic instantly shifts to the secondary link without dropping live user connections.