Voice packet switching systems and methods
View Patent ↗A switching system includes at least one packet processing circuit interfacing with at least one packet transmission link. The switching system further includes a switch fabric coupled to the at least one packet processing circuit, whereby the switch fabric is operable to switch between channels receiving and transmitting data over the at least one packet transmission link and channels receiving and transmitting data over at least one non-packet transmission link interfaced by the switch fabric.
1. A dual switching matrix fabric, comprising:
a packet switch fabric configured to receive packet traffic from a plurality of packet transmission links, wherein the packet traffic includes multiplexed voice streams; and
a TDM switch fabric configured to receive TDM traffic from a plurality of TDM transmission links;
wherein the packet switch fabric and the TDM switch fabric collectively perform per-voice-channel switching between the packet and TDM transmission links and between different packet transmission links, wherein performing per-voice-channel switching between the different packet transmission links includes de-multiplexing the voice streams into individual voice channels, switching the individual voice channels individually according to a path of each voice conversation, and re-multiplexing individual voice channels sharing the same next hop onto the same outbound packet transmission link.
2. The dual switching matrix fabric of claim 1 wherein the TDM switch fabric is a time slot interchange.
3. The dual switching matrix fabric of claim 1 wherein at least one of the packet switch fabric and the TDM switch fabric performs DS0-level switching.
4. The dual switching matrix fabric of claim 1 wherein at least one of the packet switch fabric and the TDM switch fabric performs per-voice-channel-level switching.
5. The dual switching matrix fabric of claim 1 wherein the packet switch fabric and the TDM switch fabric collectively perform DS0-level switching of:
data frames of the packet traffic received from the packet transmission links; and
multiplexed PCM data of the TDM traffic received from the TDM transmission links.
6. The dual switching matrix fabric of claim 1 wherein the packet switch fabric switches variable length packets.
7. The dual switching matrix fabric of claim 1 wherein the plurality of packet transmission links includes a plurality of ATM cell transmission links and a plurality of VoIP packet transmission links, wherein the packet switch fabric receives ATM cell traffic from the ATM cell transmission links and VoIP packet traffic from the VoIP packet transmission links, and wherein the packet switch fabric and the TDM switch fabric collectively perform switching between the ATM cell transmission links, the VoIP packet transmission links, and the TDM traffic transmission links.
8. The dual switching matrix fabric of claim 1 wherein the packet switch fabric and the TDM switch fabric collectively comprise a switching system of:
a PSTN network switching element; and
a network gateway bridging a PSTN network and a packet-based network.
9. The dual switching matrix fabric of claim 8 wherein the switching system is deployed as the PSTN network switching element or the network gateway.
10. The dual switching matrix fabric of claim 1 further comprising means for interfacing between the packet switch fabric and the TDM switch fabric, including:
means for converting packet traffic into generic-format traffic for switching by the TDM switch fabric; and
means for converting generic-format traffic into packet traffic.
11. The dual switching matrix fabric of claim 10 wherein the generic-format traffic comprises frame-encapsulated packet data in which frame headers and trailers include control information.
12. The dual switching matrix fabric of claim 10 wherein the generic-format traffic substantially conforms to a standard high-level data link control (HDLC) protocol.
13. The dual switching matrix fabric of claim 12 wherein the standard HDLC protocol is a standard protocol for point-to-point communications and point-to-multipoint communications.
14. The dual switching matrix fabric of claim 12 wherein the standard HDLC protocol is selected from the group consisting of:
frame relay protocol;
link access procedure-balanced (LAP-B) protocol;
link access procedure-data channel (LAP-DC) protocol;
point-to-point protocol (PPP) protocol; and
synchronous data link control (SDLC) protocol.
15. The dual switching matrix fabric of claim 12 wherein the standard HDLC protocol is configured for acceptance of variable-length voice mini-packets, a total bandwidth not greater than 64 Kbps, and error detection and recovery capabilities.
16. The dual switching matrix fabric of claim 1 further comprising at least one service module that performs interfacing between the packet switch fabric and the TDM switch fabric.
17. The dual switching matrix fabric of claim 16 wherein the at least one service module performs packet processing, including voice compression and echo cancellation.
18. The dual switching matrix fabric of claim 16 wherein the at least one service module is a plurality of service modules, including:
a first service module that performs interfacing between the packet switch fabric and the TDM switch fabric for VoIP traffic;
a second service module that performs interfacing between the packet switch fabric and the TDM switch fabric for AALI traffic; and
a third service module that performs interfacing between the packet switch fabric and the TDM switch fabric for AAL2 traffic.
19. The dual switching matrix fabric of claim 1 further comprising a plurality of packet network interface controllers, wherein the packet switch fabric receives packet traffic from each of the packet transmission links via a corresponding one of the packet network interface controllers.
20. The dual switching matrix fabric of claim 1 further comprising a plurality of TDM network interface controllers, wherein the TDM switch fabric receives TDM traffic from each of the TDM transmission links via a corresponding one of the TDM network interface controllers.