|Find out how to setup and use the most advanced Mobile, VoIP, SMS and Web functionalities.|
|Ismerje meg, hogyan tudja beállítani és használni a legkorszerűbb mobil, VoIP, SMS és web funkciókat.|
If your company has several extensions, then using a Direct Dial-In service is necessary. It is modern, its quality is higher than that of the old telephone networks, since it does not need external connections for communication within the company. This article will tell you how you can get such a service.
Direct Dial-In (DDI) or Direct Inward Dialling (DID) is a service offered by local telephone companies to connect their network to the customers' PBX (Private Branch eXchange switches calls to the desired extensions within the local network).
A SIP gateway (Session Initiation Protocol makes, ends and maintains connection during a multimedia session) makes it possible by connecting those DID numbers to both the Internet and the PSTN (Public Switched Telephone Network is the analog telephone network of the last century, including landline and mobile telephone networks). The gateway translates and routes calls between the two networks.Steps of Setup (as demonstrated by Figure 1)
Figure 1 - Setup Direct Dial In (DID) with Ozeki Phone System XE
Get some numbers from a service provider (whether it is landline or gsm, it does not matter, it should only be able to operate in the region). A telephony operator reserves some dedicated internet connection or some E1 / T1 lines.
When you have the range of numbers range reserved, a DID operator has to collocate a SIP gateway. Recently, Internet-connectivity for interconenction with other telecom operators is so widespread, that it might not even be necessary to get a gateway.
You need to analyse the bandwidth requirements for the call: usually 8 Kbps is needed for each active call.
It is the ratio of physical connections to virtual numbers. Recently, 1:20, 1:10 ratios are common, which means that although you get 10 or 20 DID's, your real capacity will be 1 call at a time.
You also need a softswitch (or H.323 gatekeeper, or SIP server). One of the best choices in market is Ozeki Phone System XE. Ozeki supports both SIP and H.323 and has excellent PBX features that guarantees a valuable service.
A good billing and customer-care solution should provide support at least for:
Ozeki Phone System XE is the recommended gateway or softswitch for DID setup, because of its versatility, multifuncionality and easy usage. It can offer you these due to its next generation technology and high expertise.
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