What is CLI Route and Non-CLI VoIP Route

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What is CLI Route and Non-CLI VoIP Route

The Caller ID feature was originally developed for the PSTN (Public Switched Telephone Network) system. The system is engaged with the public telecommunication service. Subsequently, the usefulness of CLI had invoked others to include it in their activities. 

— For its data collection aspect, more and more businesses use this feature to collect data from inbound calls. That’s why this feature became so popular. The feature also lets businesses improve their responses to subsequent calls.

There are several types of VoIP routes. Among them, the CLI and the Non-CLI routes are quite popular. We will broadly discuss these two VoIP routes in today’s article. 

Now you need to know about the types of VoIP routes before knowing what CLI and Non-CLI are in VoIP. The followings are the types of VoIP routes – 

Types of VoIP Routes –

  • CLI Route: First of all, the caller ID of the caller will be displayed in this type of route. The call will go through multiple carriers before finally being received by the recipient. A fun fact is – this type of VoIP route is listed as white and many foreign countries like the US tend to use this route in their public telecom monopoly.   
  • Non-CLI Route: This is just the opposite of CLI. Meaning, the called ID will not be visible in this type of VoIP route. This type of route is marked as grey and gateways like GSM (Global System for Mobile Communications) can terminate these types of calls.
  • Direct Routes: The first rule of this termination is there are no intermediaries while the call is passing from the provider to the final destination. Basically, the route provider owns terminating equipment in this type of route. The call reaches directly to its final destination without any interference.   
  • TDM: The full abbreviation of TDM is Time Division Multiplexing. This type of termination of the VoIP route has a similar configuration as traditional phone service. 
  • PRI: This type of termination route is probably the most uncommon. PRI or Primary Rate Interface is used by the Integrated Services Digital Network to carry multiple DSO voices. It also transmits data between user and network.    

What is a CLI route?

CLI is a type of telephone service that can be used for both analog and digital telephone services. The full abbreviation of CLI is “Calling Line Identification”. It is one of the popular routes in the VoIP telephone service. CLI is also known as “Calling Line Identity”.

—In order to identify the source of a call, whether it is a business organization or an individual person, you need this method. When there is an incoming call, the name of the caller, the phone number, or the organization that is associated with the call will be displayed. 

All the CLI routes are marked as ‘white’. By ‘white’ it means, they are legal. The law takes responsibility for the termination of these routes on any end. In addition to this, they are directly connected to the governing country’s infrastructure. 

This makes it the best among all types of routes in terms of containing caller information and quality. Users can experience international quality audio in this type of VoIP route. Due to the direct accordance with the law, these are reliable for technical aspects and connectivity. Its excellent quality makes it more expensive than other types of routes. 

The Users of Calling Line Identification – 

The user of CLI VoIP routes can either be a person or an organization. The importance of using CLI routes can be personal or professional. Anyone can get a suitable Calling Line Identification for his personal reason or if he is annoyed with the traditional phone call system.

Internet Service Providers 

Calling Line Identification is very effective for preventing the misuse of an account by unauthorized callers. This reason is vital enough for the internet service providers. They use this identification feature while providing remote access services to consumers. They also customize their dial-up system to pop-up specific caller ID strings while calling.


Sometimes, practice something that seems to be inappropriate for the country’s law while they try to hide their caller IDs by spoofing. Therefore, they often use calling line identification to remain untraceable while obeying the law at the same time. This route is also needed for providing toll-free numbers to their consumers to call back.   

Mobile Dealers

CLI is crucial for mobile providers to automatically connect caller IDs to voice mail numbers. In a nutshell, calling line identification is needed for the voicemail option. — Without any password or authentication, this feature relates to the voicemail that is associated with the number. Sadly, this option is no longer used for the frequent reports of spoofing. It has been replaced with a more secure option.

What is a Non-CLI Route?

The Non-CLI or Non-Calling Line Identification is marked as ‘grey’. In this type of VoIP termination route, there is no caller information displayed at the time of termination. A random or blocked call will be displayed this time.

In terms of quality, non-CLI routes are quite decent. Most of the time, the quality of calls of both CLI and Non-CLI routes is standard and international level. Furthermore, it uses cellular service gateways like GSM for handling traffic and terminating calls over the regional telephone network. 

— But that doesn’t necessarily mean the quality will always be as you expect. Because a number of factors matter regardless of the type of the route.

Non-CLI are marked as ‘grey’, which is restricted in many countries for the lack of legality, proper information, and possible violations of the termination process.

That’s how a call through Non-CLI route may look like –


The Difference Between a CLI and Non-CLI VoIP route –

After reading the definitions of both CLI and Non-CLI VoIP routes, you may already have figured that these two VoIP routes have some differences. Let’s see CLI vs Non-CLI VoIP routes –

CLI RouteNon-CLI Route
This is labeled as ‘white’ in most countriesThis is labeled as ‘grey’ in most countries
This route is considered legal by the country lawThis route is not considered legal by the country law
This route is adequately connected to the telecom infrastructureThis route doesn’t corporate with the telecom infrastructure
The quality of audio transmission is superiorThe quality of audio transmission is almost similar to CLI
Aside from GSM, other types of cellular service gateways can be used to manage trafficIn order to manage traffic, it uses cellular service gateways like GSM.
Caller ID or information is displayed to the end-user at the time of terminationCaller ID or information isn’t displayed to the other end 

Bottom Line:

VoIP routes are essential for wholesale VoIP termination business. Because the routing needs to be routed for the sake of VoIP termination. To achieve that, various types of VoIP routes are needed. And CLI and Non-CLI routes are some of the popular ones.

We recommend getting the CLI routes as they are marked as legal if you want to start a Wholesale VoIP Business. And contact a reputed VoIP service provider like WD Telecom for better management, rather than starting from scratch.

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