System having a meshed backplane and process for transferring data therethrough

• US 6,611,526 B1
• Filed: 05/08/2000
• Issued: 08/26/2003
• Est. Priority Date: 05/08/2000
• Status: Expired due to Term

• Current Assignee: ARRIS Enterprises LLC (CommScope Holding Company, Inc.)
• Original Assignee: ADC Broadband Access Systems, Inc.
• Inventors: Chinnaswamy, Kumar, Dormitzer, Paul H.
• Primary Examiner(s): Yao, Kwang Bin
• Assistant Examiner(s): NGUYEN, HANH N
• Application Number:
  US09/566,540
• Time in Patent Office: 1,205 Days
• Field of Search: 370/422, 370/426, 370/351, 370/406, 370/400-405, 370/423, 370/359, 370/362, 370/360, 370/369, 370/389, 370/419, 370/420, 370/222, 370/227, 370/223, 370/224, 370/257, 370/258, 370/242, 370/244, 370/421, 370/424, 709/201
• US Class Current: 370/406
• CPC Class Codes: H04L 12/6402 Hybrid switching fabrics

Abstract

A meshed backplane has dedicated pairs of connections for high-speed serial connection in each direction between each of multiple application modules and each other application module. A management/control bus is provided for out-of-band signaling. The mesh of serial differential pairs may be used for management/control bus signals when necessary. A time division multiplexing fabric is also provided for telephony applications. A star interconnect region is provided for distribution of signals from redundant clocks.

Claims

1. A process for switching data flow from one of a plurality of data communication application modules in a chassis interconnected across a backplane in said chassis, said process comprising the steps of:

A) receiving data at a one of said modules;

B) applying said data m bits at a time to an m-bit-wide parallel bus, where m is greater than one;

C) determining on which port of said one of said modules said data is to be transmitted, said port being directly connected through said backplane to another one of said modules to which said data is to be directed;

D) appending a tag to said data to indicate on which port said data is to be transmitted;

E) gating said m bits of data into a channel associated with said transmitting port;

F) transmitting said data from said transmitting port across said backplane to said other one of said modules to which said data is to be directed; and

G) providing control data for the receiving and transmitting data over a bus, wherein the bus is connected to each of the plurality of data communication application modules and a chassis control module.

2. The process of claim 1 further comprising the step of serializing said m bits of data before transmitting said data.

3. The process of claim 1 wherein said data is transmitted on a differential pair of connections.

4. The process of claim 1 wherein said transmission is self-clocked.

5. The process of claim 1 wherein said process proceeds simultaneously with and independently of the same steps being taken in another of said modules.

6. The process of claim 1 wherein it is determined in step (C) that said data is to be multicast through multiple ports of said one of said modules, each of said multiple ports being directly connected through said backplane to another one of said modules to which said data is to be directed;

the tag in step (D) indicates multicasting according to a mask indicating multicast transmitting ports; and

steps (E)-(F) occurs simultaneously for each of said multicast transmitting ports.

7. A meshed backplane in a chassis for interconnecting N data communication application modules for data communication between them with N greater than 2, said meshed backplane comprising:

N(N−

1) full-duplex serial links each connecting one of said N application modules with another with a minimum throughput of 64 kilobits per second;

at least two redundant management information buses each providing a connection to each application module and to at least two chassis control modules; and

an embedded clock signal, wherein the data communication is self-clocked.

8. The backplane of claim 7 wherein each of said full-duplex serial links comprises one differential pair dedicated to transmission from one of said application modules to another and one differential pair dedicated to receiving to said one of said application modules.

9. The backplane of claim 7 further comprising a power distribution system.

10. The backplane of claim 7 further comprising a telephony mesh.

11. A data switch, comprising:

a backplane mesh organized as a plurality of slots to connect to a plurality of application modules, said backplane mesh providing an independent data path from each said slot to every other slot, said backplane mesh providing a loopback in each said slot;

a controller module having a routing table; and

a bus connected to each said slot and said controller module, said bus providing control data for the data flow through the backplane mesh, whereby said independent data paths enable different types of data traffic to flow simultaneously through said data switch.

12. The data switch of claim 11 wherein each said slot has a slot ID.

13. The data switch of claim 11 further comprising:

at least one mesh communication chip (MCC) having a plurality of channels,

said slots having a plurality of ports, each said channel in said MCC linking to a port.

14. The data switch of claim 13 further comprising:

a slot ID for each said slot; and

,

means for said MCC to transmit said slot ID,

whereby flexible routing of said backplane is enabled.

15. The data switch of claim 13, wherein said MCC further comprises:

a plurality of FIFOs, one FIFO for each channel;

means for receiving a packet having a destination mask;

means for reading said destination mask;

means for copying said packet to appropriate ones of said plurality of FIFOs in response to said destination mask,

whereby said packet may be substantially simultaneously transmitted over a plurality of channels.

16. A method for flexibly routing a backplane, comprising steps of:

providing a backplane mesh organized as a plurality of slots to connect to a plurality of application modules;

providing each said slot with a slot ID;

reading, upon insertion of each said plurality of application modules into a slot of said plurality of slots, ID of said slot;

transmitting from each inserted application module the slot ID of the slot to which said application module is connected;

building a routing table in response to each said transmitted slot ID,

whereby said backplane may be flexibly routed; and

building a mapping table in each said application module, wherein each mapping table is a subset of the routing table.

17. The method of claim 16 further comprising the step of controlling differential line impedance and length

whereby signal integrity is maintained and high speed operation is enabled.