The Key System Emulation is a widely used service in legacy PBXs simplifying the direct connection to the available PSTN lines. On the Quadro, the usage of Key System Emulation services is limited to the IP phones attached to the Quadro through the available IP lines and provides direct connection to the available PSTN lines and SIP networks. In its turn, the IP phones are limited to the following models with the perspective to enlarge the list of recommended IP phones in the future:
How Key System Emulation works:
Depending on the model, the IP phone has a number of programmable keys available. Basically, all programmable key should have an LED, which can be switched ON, OFF or blinking. If an IP phone has a display, the programmable keys may also have an additional description (like what the particular programmable key does or just a name) displayed on it.
On the Quadro, Shared Line Appearance (SLA) lines act as an intermediate link between the external PSTN lines or SIP servers on one end and the programmable keys on the IP phones. The SLA lines should be first configured on the Quadro from the Key System Emulation page. Each SLA line can correspond to one of the external PSTN lines or be a direct connection to a SIP server. Once configured, SLA lines can be assigned to the programmable keys on the IP phones. For the incoming and outgoing calls to be handled, each programmable key will correspond to the particular PSTN line or SIP network (server). The same PSTN line or SIP network can be configured on the different programmable keys for different IP phones.
When the incoming call comes to an SLA line (from PSTN or SIP user), all IP phones that use the Key System Emulation are starting to ring and the programmable key assigned to the corresponding SLA line is beginning to blink on all IP phones. To pick the incoming call push the blinking programmable key on any of the ringing IP phones. The corresponding programmable key will stop blinking on all other IP phones, the IP phone rings stop and the programmable keys go to the state ON indicating that the line is busy.
If a user of one IP phone holds an active call performed on the SLA line, the programmable key is starting to blink on all IP phones. The user who has held the call can then inform the other IP phone to pick up the held call. To pick the held call, the user of the other IP phone should simply push the blinking programmable key on his IP phone. Once the call is picked, the corresponding programmable key will show solid light (busy) on all other IP phones.
To make an external call through the certain SLA line, the programmable key assigned to that SLA line should be in the idle state. The IP phone user should then push the corresponding programmable key, depending on what line he needs to get, and wait for a dial tone. Once the dial tone is heard, user can dial the number and the push the OK/Dial button on his IP phone. The call will be placed through the corresponding SLA line. During the call, the programmable keys assigned to that SLA line on all other IP phones goes to the state ON indicating that the line is busy.
Note: If the IP phone is configured through the Plug-and-Play option while connecting to the Quadro, the first few programmable keys on the IP phone will be by default assigned to the first SLA lines on the Quadro in the consequent order.