Discover how our products can revolutionize the way you communicate and collaborate.


Explore our advanced voice solutions designed to optimize your communication workflows.

Diverse range of DID number solutions designed to enhance your communication capabilities.

Experience unparalleled communication efficiency with our advanced SIP Trunking Solutions.

Cutting-edge technology to proactively detect and neutralize spam flags on your DID Numbers.


Wherever your audience is, our platform ensures seamless messaging across diverse channels.

Build customer journeys by fostering interactive conversations, all within the framework of your app. 

Connect with your audience in a simple and effective way through our cutting-edge SMS platform. 


Harness the power of IDT as your chosen carrier while leveraging your platform’s advanced features and services.

Integrate Twilio with our robust carrier routing platform to achieve unparalleled Voice termination system.

Experience reliable and high-quality communication services while leveraging the advanced capabilities of Genesys. 

Integrate IDT with the collaborative strength of MS Teams, unlocking efficient and feature-rich communication. 

Experience the power of our carrier network seamlessly connected to Plivo through our cutting-edge BYOC solution. 


Experience the power of our online voice tools, designed to simplify communication management. 

Ensure the authenticity and integrity of outbound calls with our STIR/SHAKEN Verification Check tool. 

User-friendly tool to verify the reputation of your business number, ensuring that it remains trusted. 

Compare and gain insights into outbound call expenses, optimize budget, and make informed decisions. 

Easily estimate and compare the costs associated with different DID numbers providers. 

Compare inbound VoIP rates among top CPaaS providers and optimize your inbound call costs. 

Generate custom SMS templates. 


Empower yourself with the resources you need to thrive in the dynamic landscape of communication.

Articles covering a wide range of topics.

Get answers to common queries.

Find instructions to make the most of our products.

Discover telecom insights and trends.

Find definitions of popular telecom terms.

Explore how our solutions have helped businesses.

Latest telecom trends, innovations, and market insights.


A global telecom partner built to meet your needs. 

Discover the story behind our commitment to delivering innovative solutions to connect people and businesses worldwide. 

Learn about our robust network infrastructure that spans across the globe, ensuring reliable and secure connectivity. 

Got a question, feedback, or need assistance? Our dedicated team is here to help!

Find partners or sign up for partnership programs.

Learn / Blog

The Purpose of Least Cost Routing (LCR)

|  2 min
In this article

Least Cost Routing, or LCR, defines how to choose the best route for outgoing voice calls (i.e., termination) in order to get the lowest cost for the path between the caller and the recipient 

LCR Functionality

In simple terms, LCR is a software tool that applies machine learning to find the lowest cost path for phone calls. All the telecom providers, and even some big companies and contact centers, possess some least cost routing tools to save money, avoid disruptions, and improve reliability in case of a service suspension. 

The usability of LCR is based on the rate decks that are installed into it since the deck determines the routes for all possible routes across all of the voice carriers in its memory. Format of the rate deck uses the 6-th and 7-th digit of the phone number to be dialed, which structures out as “NPA-NXX”. The phone number is also called a DID or Direct Inward Dial. 

There are multiple costs to consider based on where the call is made and destinated. For the inter-state calls, the caller and the recipient are located in different states. For the intra-state calls, the caller and the recipient are located in the same state. In a very short time (<1 sec), LCR will assess the best call route between the origin and the destination, allocating the path between them both – with the lowest rate for the call. 

The Benefits of Using LCR

Classical call routing methods are not efficient, and at the same time, they are also not very cost-effective for the users; that is the reason why IDT adopted LCR a decade ago. LCR is a novel, cloud-based method that unifies the capabilities and performance of multiple voice carriers in one smart call routing platform. As a result, our communication platform redefines how companies can route their calls. 

Least call routing lcr

IDT is among the rare cloud communications providers that offer toll-free least cost routing, exploiting the power of several toll-free service providers for complete redundancy, cost efficiency, and control. Our clients can choose preferred routing and quality options, call boundaries, routing parameters, etc. They will then be ready to redirect the traffic via the optimal route. The clients can also customize their settings by pointing their switches to IDT’s LCR, and we will do the rest. IDT’s technology was built to provide its clients the assurance that their traffic is being handled in the best way – according to their requirements. 

The SIP trunking and CDR monitoring tools (together with LCR) enable you to better utilize and enhance your calling features within your communication system. Feel free to contact us for a quick demo on how to implement Least Cost Routing. 

Share this article

Leave a Reply

Your email address will not be published. Required fields are marked *


Meet our wholesale voice routing

Fulfill all your voice calling needs with our category leading wholesale A-Z Voice Termination.
Try IDT Express for a $25 Credit

Get $25 Free Trial Credit

Get IDT Express articles in your inbox

The best source of information in the telecom industry. Join us.

    Most Popular

    |  7 min
    Introduction to Toll-Free Forwarding In today’s fast-paced business landscape where...
    |  7 min
    Introduction to Caller ID Reputation Caller ID reputation is a...
    |  6 min
    The European Union’s General Data Protection Regulation (GDPR) has permanently...