UK eNumbers

The major benefit at day one is that the much heralded free calls via the internet is finally here!

The VOIP systems available now, uses a closed architecture to route calls through the internet. Calls between users of the same software or hardware are inexpensive and often free. However, if you want to make a call outwith those systems (i.e. to another provider, landline or mobile telephone number) the calls can become expensive as you cross over onto the public or mobile telephone networks. When Voice Over IP was originally introduced, there was much talk of "free worldwide calls" and "no more line rental" but there's always been something missing to enable these features. Well, ENUM is the missing link in the chain!

As the technology develops, things like mobile SIP will bring the telecommuncations industry closer together than ever. Imagine being able to recieve calls to your landline anywhere you have a mobile internet connection (either through your phone or laptop device) without paying astronomical charges for call redirection, international roaming and whatever other charges your provider can throw at you.

But wait, there's more... You could save all your contact details: fax and phone numbers (work, mobile and home), e-mail and home addresses, voicemail etc. all in one ENUM entry. This address is used to store records, that contain whatever contact details you wish to include, such as mobile telephone number, landline telephone number, fax, web site address and email address. You can then add rules to redirect people to one or other of these contact details depending on who the person is, what time it is and so on.

For example calls after 5.30pm could be routed to your mobile, whilst all contacts during office hours could be via e-mail.

For the techies!

Unlike the proprietary Voice Over Internet Protocol systems we have now, ENUM uses open architecture to map telephone numbers to a domain. This allows independent SIP systems to communicate with each other directly through the internet without having to access the Public Service Telephone Network (PSTN)

At present it is easy to connect from one employee within a company to another in the same company using an IP voice network. That still works if an employee is a home worker who connects over the Internet - the system recognises the numbers within its system and connects the call as if the home worker were in the office.

However, if someone within Company A wishes to connect to someone in Company B using the Voice Over Internet Protocol (VOIP) currently, they need to connect to a telephone network provider e.g. BT who makes the connection to the other company. Obviously this costs money, as the calls are charged for by the telephone company.

The advantage of ENUM is that it will enable Company A's system to connect with Company B's system via the Internet without having to connect to the telephone network for the call.

This is done by translating the telephone number into a domain name:

e.g.0141 530 8898 becomes 8.9.8.8.0.3.5.1.4.1.1.4.4.e164.arpa where '44' is the UK's international dialling code, 'e164' is the name of the telephone numbering system and '.arpa' is the Internet infrastructure equivalent of .uk or .com. A computer can understand and connect to this address in a fraction of a second which makes ENUM a quick, stable and cheap link between the telecommunications system and the Internet.

Last Updated on Sunday, 15 March 2009 13:14