Real-Time LRN Dip

Real-Time LRN Dip — Every Call, Every Time.

NPAC-sourced LRN dips with sub-10ms P99 latency. SIP-switch integration ready. Instant provisioning, per-call or flat-rate pricing.

Get API Access NowSee How It Works
<10ms
Live Dip P99
NPAC
Data Source
SIP Ready
Integration
# SIP B2BUA pre-dial hook
Dipping DNIS: +16145550037...
✓ lrn: "6145550037"
✓ Route via OCN: 6529
✓ Dip latency: 8ms

Infrastructure-Grade

Built for Production-Scale LRN Dips

Every feature is designed for the demands of carrier-grade call routing.

⚡

True Real-Time Dips

Every LRN dip hits our live NPAC-sourced database. No stale cache TTLs, no batch-delayed data — live porting status on every query.

🌐

Distributed Infrastructure Advantage

Our LRN database is replicated across distributed U.S. regions — geographically optimal for nationwide traffic, delivering sub-10ms round trips from major U.S. hubs.

🔌

SIP Integration Ready

Designed for SIP softswitches. Drop-in compatible with FreeSWITCH, Asterisk, OpenSIPS, and Kamailio via HTTP/REST. No proprietary protocols.

🤖

Instant Provisioning

API keys delivered immediately after registration. No waiting for sales approval, no manual onboarding — just sign up and start dipping.

📊

Full Field Set

LRN, OCN, SPID, rate center, LATA, ported flag, line type — all returned in a single API response with latency metadata included.

💡

Smart Redis Cache

Multi-node Redis caching layer with configurable TTLs balances freshness against throughput, delivering millisecond response for repeat lookups.

Start Free — 1,000 Lookups Included

Developer-First

SIP-Friendly REST API

Request

POST https://api.sipsmart.io/v1/lrn/dip
{
  "dnis": "+16145550037",
  "ani": "+12125550001",
  "mode": "realtime"
}

Response — <10ms

200 OK
{
  "dnis": "+16145550037",
  "lrn": "6145550037",
  "ocn": "6529",
  "spid": "6529A",
  "ported": true,
  "line_type": "wireless",
  "rate_center": "COLUMBUS",
  "latency_ms": 8
}
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Simple, Predictable Pricing

No Surprises. Ever.

We charge less than legacy providers and publish our prices openly. No setup fees, no hidden costs, no annual lock-in required.

Starter
$0.0001
per lookup
  • ✓ Real-time LRN dip
  • ✓ Standard latency
  • ✓ HTTPS API
  • ✓ 1,000 free lookups
Best Value
Volume
$0.00005
per lookup (1M+/mo)
  • ✓ Real-time + batch
  • ✓ <10ms Ohio cluster
  • ✓ Dedicated endpoint
  • ✓ Priority SLA
Enterprise
Custom
flat-rate
  • ✓ DB replication
  • ✓ On-prem option
  • ✓ SLA guarantee
  • ✓ Dedicated support

🛡 Pricing Guarantee

We will match or beat any competitor's published price for equivalent LRN lookup volume. Contact us with a quote.

Get Started Free

FAQ

Real-Time LRN Dip FAQ

Have another question? Email us at support@sipsmart.io

  • An LRN dip is a real-time query to determine the Location Routing Number of a target telephone number. Carriers perform LRN dips before completing calls to ported numbers to ensure they route to the correct terminating carrier, not the original carrier of record.
  • Incorrect or stale LRN data causes misrouted calls, failed completions, and potential FCC compliance violations. Real-time dips on every call ensure you're always routing to the current terminating carrier.
  • Our REST API speaks JSON over HTTPS. For FreeSWITCH users, we publish an ESL-compatible module. For OpenSIPS and Kamailio, we provide a REST client configuration. Most switches can be integrated in under an hour.

Start Dipping in Minutes

Instant API provisioning. 1,000 free LRN dips. No sales call required.

Get API Access NowView Pricing

1,000 free lookups included • No credit card required • Instant provisioning