This article provides instructions on how to setup Inbound calling to your Sippy soft-switch. The term "Inbound" in this article refers to call traffic that arrives at the Sippy softswitch from the outside (upstream). Call traffic can come from your DID provider or customer. The article contains instructions which will help you to configure a DID number and assign it to account or an IVR application intended to receive a call (i.e. answer the Inbound call).

Setup flow

1. Open the DID Pool and click the Add button:

2. Fill in the DID and Incoming DID/CLD fields:

DID - means the DID number itself. It's up to you to select which format to use here.  It can be E.164 or prefixed with "+" or shortened 80023322.  Note: if you're going to have accounts that will make calls to DID numbers, then use the format which will be the most convenient for your accounts to dial.  A call from an account to a DID number is called Late DID Recognition.

Incoming DID/CLD - means the number that the DID provider sends to the softswitch, it's the dialed number (CLD) and it's present in the URI part of the incoming INVITE request.

DID Translation rule - means the Translation Rule to be applied against the DID number after the call is authenticated.  The DID Translation Rule can be useful when the DID provider sends the CLD prefixed with "+" but you need to remove the prefix.  Setting the value as "12380023322" means to translate everything to "12380023322" (i.e. equivalent to "s/.*/12380023322/").

3. As an additional measure Sippy recommends that you use the Vendor & Connection fields in the Authentication Rules section. This is for authentication of incoming traffic only from a specific Remote IP (IP from which DID provider's traffic will arrive at Sippy):

3.1 Add the DID provider as a Vendor and his gateways as Connections specifying real IP of your DID provider:

3.2 Set the Vendor and Connection in the settings of the DID number:

It is also possible to set a Vendor only. In this case it means that a call to the DID is allowed from Any connection of this particular Vendor.

Multiple Authentication entries are allowed too, they can be useful when the DID provider sends calls with a CLD in different formats and both calls should be authenticated. For example:

4. Next, click on Assigned to and tie your DID number with some Account or IVR application. This will result in the incoming call to the DID number being routed to a specific Account or IVR application:

5. If your call should be routed from the DID number to the registered Account, verify the Incoming Routing of account:

6. The last step is to make sure that the Account assigned has On-net scope Enabled. Open the Routing Group which is tied to the Account and check On-Net Routing section:

Set everything to the default values recommended by Sippy and save Routing Group settings. More info...

Changes related to Rates, Routes, Destination Sets, Tariffs, DID numbers, DID Charging Groups and Routing Groups may not be applied immediately after you make them.  When you make changes, you need to wait at least 1 minute so that the system can update its internal "cache".  Sometimes, when you perform a "heavy bulk" update of (for example) multiple destination sets, the system may require more than 1 minute. Read more...