How to configure SIP Alias? What is SIP Alias? SIP Alias is an alternative address for your main SIP Address. Normally, when you have a user account for one ITSP, you have one SIP address provided by the ITSP. However, with SIP alias, you can own multiple SIP addresses over one user account. When you register with a regular user account, alias are registered as well as the main SIP address. Then, when somebody dials the alias, the SIP URI bound to the alias will ring. How to achieve DID (Direct Inward Dialing) with SIP Alias DID - Direct-Inward-Dial (also called DDI in Europe) is a service offered by a telephone company that provides a block of telephone numbers associated with one phone line for calling into a company's PBX system. The employees can have their extension numbers respectively, and the caller, via DID function on Vigor router, can dial to any one of the extension numbers directly without passing through auto-attendiant. Below shows a scenario: [email protected] is the main SIP trunk set on Vigor 2820 IP PBX, and [email protected] is set as SIP alias on Vigor 2820 IP PBX as well. Both share the same SIP account. When you complete the registration for the main SIP trunk, an additional registration for the SIP alias will be automatically performed. Therefore, in this case, if Benson wants to call Jacky, he has two options. One is using auto-attendant by calling [email protected]. After hearing the greeting, Benson should press the extension number 101 to call Jacky. The other is using DID by calling [email protected], the call will be forwarded to extension number 101 directly by the PBX system. Follow the steps below to setup SIP Alias and achieve DID. 1. Create a SIP Alias. First of all, make sure your VoIP Service Provider supports SIP Alias. For example, iptel.org 1 provides such service. When you register an SIP account [email protected] on iptel.org, you will be provided with a sip alias [email protected] as well. See below. 2. Setup SIP account on Vigor 2820 IP PBX. Open the IP PBX>>Line Setting>>SIP Trunk page and configure the SIP account as follows. 2 3. Setup SIP Alias on Vigor 2820 IP PBX. Open the IP PBX>>SIP Trunk List page and click on Alias List to enter the SIP Alias setup page. 4. Press one index and input the SIP Alias in the Alias Number fields. Select the associated SIP account from Alias of SIP Trunk, which was created in step 2. Route the call to Jacky by selecting Forward To Extension and the extension profile 1-101. 3 5. The configuration is completed. Make sure the extension number 101 is registered. Next, Benson can make a direct call to Jacky by calling [email protected] . 4