What Are Trunk-to-Trunk Transfers?

With a stand-alone telephone that is connected to a single line only, it is not possible to do very much with an incoming call other than answer it. On the other hand, a business phone system offers a great deal more functionality, such as the ability to place calls on hold, to transfer to another extension and to connect with a third-party piece of telephony equipment, such as a voicemail system. Although these are all useful features of modern phone systems, one of the most popular today is performing a trunk-to-trunk transfer. This sort of feature is not available with all business exchanges and is sometimes misunderstood by operatives. What is it and how does it work?

The Essentials

Trunk-to-trunk transfers have been around with private business telephone systems since the days of analogue lines. These days, they are much more likely to be conducted digital network telephone services, usually ISDN lines. When a call connects to a telephone system, it is answered by a member of staff or an operator. Usually, this employee will try to transfer the caller to the department or individual being asked for internally, via their extension. However, if the call needs to head outside of the system, then a trunk-to-trunk transfer will be needed. Please note that all that trunk means is 'telephone line'. So, the operative is simply receiving a call on one trunk, or line, and transferring it back out on another.

How Do They Work?

With most keyphone exchanges, such as Toshiba phones systems, it is possible for the operator at reception to see whether another extension is in use. Therefore, they can either park the call or transfer it to a voicemail box. With some sophisticated systems, it is possible for a person to show their extension as 'out of office'. This means the operator can take a call for someone and seamlessly transfer it to their mobile phone without the caller even being aware that their call is being routed externally. Offering the ultimate in customer service, it means that staff who are out and about remain reachable in just the same manner as their clients are used to, without having to give out two or three separate telephone numbers to track someone down.

Call Costs

When a call into a telephone system is generated from the network, it is at the caller's expense. However, when a trunk-to-trunk transfer is made the second part of the call is made from the receiving end, so two call charges apply, one for each caller. Since a trunk-to-trunk transfer will only end when one or other party hangs up, businesses which use this handy function should budget for additional call costs.