 In this module, we shall understand what is INEM. We'll take a formal definition of it and then we'd look at some of its types. INEM is actually the electronic numbering that is an allowance to prevent the overall abandonment of the telephone numbers once the NGN network adoption is made. It means this is a whole set of standards and mechanisms that allows the interoperability of the telephone numbers along with the IP addresses. It is specifically for transforming the telephone numbers into the domain names, the same domain names, the ones that we've seen for IP addresses. It enables the users and the providers to continue using their telephone numbers as they were using them in legacy telecom networks. There are some variants of INEM depending upon its role. We'll start with the user INEM. It is also known as the public INEM. It was specified by the IETF. It is aimed at allowing the owner or holder of a telephone number to have control of his communications, that is, whom the user can contact, who all can contact the users, what all services can be exposed by this user and what all services can this user access on other machines. It actually is a way to allow an end user to advertise itself on the IP network using its telephone number. Against the telephone number, the user actually can link and append some additional information. So different users can recognize this user by using the telephone number of this particular user in a certain manner. This user INEM has some natural advantages, that is, instead of maintaining different identifiers for different services and applications, the user can just now have a single identifier that is extracted or evolved out of the telephone number of the user. This particular ID can be used to identify the devices, the terminals, the software applications which the user is using or the user wishes to advertise. The applications could be not limited to the telephone, the email, the web-based services, etc. It provides translation of the E.164, that is, the ISDN and PSTN-based telephone numbering specified by the ITUT, into the DNS acceptable tree structure through appending a suffix called the public root E.164.ARPA. Like we have discussed, user INEM, we also have another INEM type called the infrastructure INEM. It is also known as the carrier or private INEM. It was specified by the GSM Alliance and its aim is to allow routing of calls and establishment of interconnection between different service providers. So the infrastructure INEM is a database again, just like the user INEM we discussed briefly. It is used between the carriers or the service providers to share the subscriber-related information once they pair with each other. It is important to mention here that in the case of user INEM, the control to divulge and reveal the information on need-to-do basis was within the control and affair of the user. Here, since we are talking about the service provider, which now has the information of that user, can now control the subscriber-related information and can reveal this information to its peers on need-to-do basis. The carrier INEM is actually a large-scale operation that is to route traffic between different operators coming from different users. Each user is identified through its user INEM. So it is targeted to exchange the IP traffic, voice, video, data between different NGN service providers and operators. Using IP pairing, a given operator may locate a destination operator for IP traffic exchange. It could be from an individual user or it could be from a group of users.