Configure 2 SPA3000 with Asterisk to connect 2 buildings

We want to connect 2 buildings by telephone by means of 2 SPA3000 devices and an Asterisk installation. There is an analog telephone line (PSTN, POTS, landline) available in 1 building. The 2 buildings are on the same internal ethernet network, even on the same subnet. The task consists of CONFIGURING the 2 Sipura devices and the Asterisk server. All hardware is up and running. The following is already present: * Building A: - 1 SPA3000 device, connected to a PSTN line - A permanent PSTN line - Ethernet network: the SPA3000 device A is connected to the network with fixed IP [login to view URL] * Building B: - 1 SPA3000 device, with one analog telephone connected - A Debian server with a fresh Asterisk install on it, connected to the same network as the SPA3000 devices, with fixed IP [login to view URL] - Ethernet network: the SPA3000 device B is connected to the network with fixed IP [login to view URL] OBJECTIVES: 1) When the analog phone is picked up in building B, we want to hear a dialtone. 2) When a 99 is dialed on the analog phone in building B, we want the call to be routed through the landline of building A, the number 99 being cut off from the complete telephone number. 3) When another number is dialed from the analog phone in B, this means an extension configured on the Asterisk. 4) When the landline in building A gets an incoming call, the analog phone in building B rings and can be picked up to answer the call. 5) Configure one example trunk in the Asterisk for outgoing calls through for instance VoipBuster. 5) Configure one example extension in Asterisk for use with a VOIP softphone. 6) Install a GUI for Asterisk. The Freelancer gets entire access to SPA devices A and B and root access to the Debian server. We will give a local test phone number to dial from the landline. We will also participate to tests if necessary.