Deployment scenarios


Means of instant communications have seen rapid and unparalleled growth across the globe in the past decade. This has been possible in part through internet protocol based networks, which continue to affect all sectors due to their multitude of applications, and, in particular, voice over internet protocol (VoIP).

This article examines the regulatory status of VoIP in India and envisions its future status. The terms "VoIP" and "internet telephony" are often used interchangeably, with "internet telephony" primarily being used and referred to in the Telecom Regulatory Authority of India's (TRAI's) recommendations, as well as the licensing conditions prevalent in India.

VoIP is voice transmitted over packet switched network using the internet protocol. It enables users to make real time voice or video calls, thereby reducing the underlying cost of a traditional telephone call. On 24 October 2017, the TRAI released its Recommendations on Regulatory Framework for Internet Telephony. These note that there are two methods that have been recognised globally for voice transmission over internet protocol networks, based on the type of IP network used. These are:

  • VoIP (ie, voice is transmitted over a managed internet protocol network); and
  • internet telephony (ie, voice is transmitted over a public internet).

The primary difference between voice services on managed and unmanaged internet protocol networks is the quality of speech. Due to technological advancements, new coding techniques and the availability of higher bandwidth broadband connections, this difference is getting narrower.


Since then, TRAI has issued various recommendations and consultation papers, of which the last consultation paper was released in 2016 (ie, the Consultation Paper on Internet Telephony (VoIP)), which sought to identify issues in providing internet telephony services and address them in a holistic manner.

The TRAI 2017 recommendations were the outcome of the 2016 consultation paper and received public comments.

On the regulatory front, VoIP services are regulated, and a license is needed to provide them as explained below.

Deployment scenarios

The TRAI's 2017 recommendations listed three main deployment scenarios for internet protocol telephony:

  • computer to computer – existing licensing conditions of internet service providers (ISPs) enable parties (ie, callers and recipients) to connect to the public internet and exchange voice and data through their computers (or smartphone or tablets and compatible software);
  • phone to phone – in this case, the caller and recipient use their telephone set (fixed or mobile) for voice communications through established gateways over a managed internet protocol network; and
  • computer to phone or phone to computer – either the caller or the recipient has a computer that connects to the internet via an access network and a licensed ISP, while the other party is a normal subscriber of a telephone network (fixed or mobile) using the public switched telephone network (PSTN) through a licensed telecoms service provider (TSP).

The present regulatory framework allows the first two deployments above. For the third option (ie, computer to phone or phone to computer), the licensing conditions enable internet telephony from a computer to a PSTN abroad – however, the licensing conditions prohibit the use of E.164 numbering, as well as voice communications, to and from a telephone connected to a public network in India. This is shown in Figure 1.

Figure 1: licensing conditions

Arguably, the reason behind this prohibition is to prevent "toll bypassing" of subscriber trunk dialling or international subscriber dialling mechanisms and tariffs – if these were allowed, every call would be initiated as a local call. In fact, the TRAI 2017 recommendations also state that, when unrestricted internet telephony for ISPs were deliberated in 2007-2008, the TSPs' main argument for not allowing this was that it would impact their business model on account of a reduction of voice traffic on their network. They also argued that it would disturb the level playing field among different licensees, especially since TSPs have paid a huge entry fee and made heavy investments to create the infrastructure.

On a separate note, other service providers carrying out voice-based business process outsourcing services are specifically regulated by the Revised Guidelines applicable for Other Service Providers, dated 23 June 2021.(1)


Now that video calls over the internet are ubiquitous, the restrictions and controversy around VoIP may sound less important. But the prohibition on interconnection is a major part of current Indian telecoms regulations.

With the growing liberalisation of the telecoms sector, VoIP may soon replace traditional PSTN as the primary mode of voice and/or data communication. According to the TRAI's 2017 recommendations, the total volume of packet-based network traffic has surpassed traditional circuit switched network traffic (ie, PSTN). This is unsurprising, considering the technological advancements in the sphere of smartphones, new voice coding techniques and the availability of high-speed internet. Most TSPs in India now have IP-based core transport networks for carrying voice and data traffic.

Therefore, if a business uses or touches upon VoIP technology, or intends to move its back office from traditional telephone services to a VoIP system, the call routing process should be assessed to ensure that there is no illegal and/or unauthorised voice traffic in the process that the business adopts.

For further information on this topic please contact Suruchi Kotoky at BTG Legal by telephone (+91 22 6177 2900) or email ([email protected]). The BTG Legal website can be accessed at


(1) For further details please see "DoT - Revised Other Service Provider (OSP) Guidelines".