Private branch exchange built using an ATM Network
View Patent ↗The present invention guarantees that voice data (and other information types) will switch within a predetermined time period. Systems and methods consistent with the present invention accomplish this guarantee by, among other things, establishing permanent virtual paths between each network element, guaranteeing each voice line a slot in a packet in each frame, employing both octet switching and packet switching, synchronizing the operation of the network elements to a reference clock, and providing several levels of network redundancy.
1. A network for transporting data from an originating port to a destination port comprising:
at least one controller, each controller including:
means for receiving data in time division multiplex (TDM) format from an originating port, and
means for mapping the TDM data into fixed-length packets, wherein the TDM data is written into a predetermined packet slot permanently assigned to the originating port; and
a switching element connected to the one or more controllers including:
means for receiving the packets from the one or more controllers, and
means for separately switching the TDM data in each packet slot received from the controllers into a packet slot preassigned to the destination port.
2. The network according to claim 1 , further comprising a call server connected to the switching element, including:
means for determining the destination port associated with the data in each incoming packet slot based on a message transmitted from the controller to the switching element to the call server.
3. The network according to claim 2 , wherein the call server further comprises means for instructing the switching elements to switch the data in the packet slot into the packet slot corresponding to the destination port.
4. A non-blocking network for transporting packet data from an originating port to a destination port, including:
at least one controller connected to plural ports, wherein each controller includes an interface to receive time division multiplex (TDM) data from an originating port and a state machine to map the TDM data into packet data and to write the TDM data into a packet slot assigned to the originating port; and
a switching element including an interface to receive the packet data from the one or more controllers and a switching circuit to switch the TDM data in the packet slot assigned to the originating port into an outgoing packet slot assigned to the destination port.
5. A network according to claim 4 , further comprising a call server to determine the identity of the destination port.
6. A network according to claim 5 , wherein the call server further includes a look-up table to identify the packet slot corresponding to the destination port.
7. A network according to claim 6 , wherein the call server further includes an input/output controller to send a message to the switching element instructing the switching element to switch the TDM data in the packet slot assigned to the originating port into the packet slot assigned to the destination port.
8. A node controller connected to plural access controllers, including:
means for receiving packet data from the plural access controllers, and
means for separately switching TDM data in one packet slot assigned to an originating port in the packet data received from the plural access controllers into a packet slot preassigned to a destination port.
9. A method for establishing a switching path between an originating port and a destination port in a network having a call server and plural controllers, the method comprising the steps of:
receiving from the plural controllers packets in which TDM data from the originating port is located in a particular packet slot assigned to the originating port;
receiving a first message from the call server;
switching the TDM data in the packet slot assigned to the originating port into a packet slot assigned to the destination port in response to the first message from the call server.
10. The method of claim 9 , further comprising the step of:
continuing to switch the TDM data in the packet slot assigned to the originating port into the packet slot assigned to the destination port until receipt of a second message from the call server.