Network switching system with asynchronous and isochronous interface

• US 6,987,758 B1
• Filed: 04/07/2000
• Issued: 01/17/2006
• Est. Priority Date: 04/07/1999
• Status: Expired due to Term

• Current Assignee: Juniper Networks Incorporated
• Original Assignee: Juniper Networks Incorporated
• Inventors: Koyama, Akira
• Primary Examiner(s): Vu, Huy D.
• Assistant Examiner(s): RYMAN, DANIEL J
• Application Number:
  US09/545,888
• Time in Patent Office: 2,111 Days
• Field of Search: 370/474, 370/475, 370/352, 370/353, 370/354, 370/359, 370/356, 370/409, 370/392
• US Class Current: 370/356
• CPC Class Codes: H04L 12/40097 Interconnection with other networks LAN interconnection over a bridge based backbone H04L12/462; single bridge functionality H04L12/462
• CPC Class Codes: H04L 12/4013 Management of data rate on the bus systems modifying transmission characteristics according to link quality H04L1/0001
• CPC Class Codes: H04L 12/403 with centralised control, e.g. polling
• CPC Class Codes: H04L 12/66 Arrangements for connecting between networks having differing types of switching systems, e.g. gateways
• CPC Class Codes: H04M 7/121 Details of network access arrangements or protocols

Abstract

To provide a switching system with telephone switching function mainly on the basis of hardware processing by using isochronous channel which is a real time communication channel. The switching system comprises a gateway node connected with ISDN (Integrated Services Digital Network) and PSTN (Public Switched Telephone Network), and one or more extension nodes, and a serial bus such as IEEE 1394 bus. The gateway node transforms data rate of outside line into data rate of extension node, and the other way around, and secure a seamless communication channel. Concretely, the gateway node secures an isochronous channel, according to a request from the extension nodes or the outside line, and executes switching such as transfer or reservation. A resource manager holds a table for managing the gateway node and extension node.

Claims

1. A network switching system, comprising:

a gateway;

one or more extension nodes, each identified with a unique physical identifier and selectively identified with a unique telephone number; and

a serial bus interconnecting said gateway and said one or more extension nodes,

wherein stream data transferred on said serial bus are exchanged through said gateway between an outside line and an extension node, or between a first extension node and a second extension node,

wherein at least one said extension node comprises;

a control/memory unit for storing physical identifiers and telephone numbers of said gateway and extension nodes and for controlling said network, thereby allowing said at least one extension node to transmit and receive stream data from outside telephone numbers and from telephone numbers of other extension nodes;

an asynchronous interface, for selecting said extension node and controlling a switching timing, connected with said control/memory unit;

a rate conversion unit for converting a data rate of said stream data in said network into that in said outside line, or for converting a data rate of stream data in said outside line into that of said network switching system; and

an isochronous interface, for transmitting and receiving said stream data, connected with said rate conversion unit.

2. The network switching system according to claim 1, wherein the at least one extension node further comprises:

a microphone for inputting said stream data;

a speaker for outputting said stream data; and

a codec, for encoding and decoding said stream data, connected with said microphone, said speaker and said rate conversion unit for encoding and decoding said stream data.

3. The network switching system according to claim 1, wherein the at least one extension node further comprises:

a stream data take-in unit, for storing said stream data, connected with said rate conversion unit; and

a stream data processing unit, for processing said stream data, connected with said stream data take-in unit.

4. The network switching system according to claim 1, wherein said asynchronous interface and said isochronous interface are connected with a bus manager which controls said asynchronous interface, said isochronous interface, said control/memory unit, and said rate conversion unit.

5. The network switching system of claim 1, wherein each of said first extension node and said second extension node is uniquely identified by a telephone number.

6. The network switching system of claim 1, wherein said serial bus comprises an IEEE 1394 data bus.

7. A gateway, comprising:

a first switching unit for controlling extension nodes connected with a serial bus for isochronous transfer; and

a second switching unit for exchanging stream data between an outside line and said extension nodes,

wherein;

said first switching unit comprises a server bus manager connected with an asynchronous interface and an isochronous interface,

said second switching unit comprises a line manager connected with a codec and a control/memory unit,

said line manager exchanges said stream data between said outside line and at least one of said extension nodes, according to a request from said server bus manager,

said server bus manager manages a call-in to said extension node and a call-out from said extension node, and

each of said at least one extension node is identified by a unique physical identifier and selectively identified by a unique telephone number.