Apparatus and method for error isolation in hybrid communications systems

• US 6,873,599 B1
• Filed: 12/21/1999
• Issued: 03/29/2005
• Est. Priority Date: 12/21/1999
• Status: Expired due to Fees

• Current Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Han, Yihwu
• Primary Examiner(s): Ton, Dang
• Assistant Examiner(s): TRAN, PHUC H
• Application Number:
  US09/468,164
• Time in Patent Office: 1,925 Days
• Field of Search: 370/216, 370/217, 370/218, 370/229, 370/236, 370/236.02, 370/241, 370/214.1, 370/242, 370/244, 370/247, 370/249, 370/352, 370/353, 370/354, 370/355, 370/356, 370/395.1, 370/230, 370/248, 370250-252, 3703953-39532, 370/453, 370/236.1, 370/236.21, 370/241.1
• US Class Current: 370/249
• CPC Class Codes: H04L 12/6418 Hybrid transport
• CPC Class Codes: H04L 41/0659 by isolating or reconfiguring faulty entities
• CPC Class Codes: H04L 43/50 Testing arrangements

Abstract

A hybrid telecommunications component in accordance with the principles of the present invention affords loopback test capabilities across boundaries between circuit switched and packet switched components. A loopback test which encompasses at least a portion of the packet switched side of a hybrid system may be initiated from the circuit switched side of the hybrid device. Additionally, a loopback test which encompasses at least a portion of the circuit switched side of a hybrid system may be initiated from the packet switched side of the hybrid device. In an illustrative embodiment, when a loopback test of the circuit switched side is initiated by the packet switched side, the loopback test is carried out by the circuit switched side, with the results being reported by the circuit switched side to the packet switched side.

Claims

1. A method of testing telecommunications systems which include both circuit switching and packet switching components comprising the steps of:

(A) a circuit switching component initiating a loopback test that encompasses communications path through a packet switching component;

(B) the packet switching component returning a looped back test message to the circuit switching component; and

(C) the circuit switching component responding to the reception of the returned test message by determining that the path encompassed by the packet switching component is operational;

wherein the circuit switching component employs time division multiplexing (TDM) and the packet switching component employs asynchronous transfer mode (ATM) packet switching.

2. The method of claim 1 further comprising the step of:

(D) the circuit switching component responding to absence of a returned test message from the packet switching component by determining that the path encompassed by the packet switching component is not operational, or provisioning data is not consistent with the communications path.

3. A method of testing telecommunications systems that include both circuit switching and packet switching components, and an interwork unit between the circuit switching and packet switching components, the interwork unit providing an Internet Protocol Device Control (IPDC) and an asynchronous transfer mode Switched Virtual Circuit Capability, comprising the steps of:

(A) a circuit switching device requesting an Asynchronous Transer Mode (ATM) address in an ATM switch to establish a loopback path;

(B) an interwork unit establishing an ATM Switched Virtual Circuit with the ATM address via an ATM virtual connection through the ATM switch using the ATM address;

(C) establishing the ATM address in the ATM switch as a loopback point; and

(D) performing a loopback test from the circuit switching device through the loopback point established in step (C).

4. A method of testing telecommunications systems that include both circuit switching and packet switching components, and at least one interwork unit connecting packet switching and circuit switching components, the interwork unit being an Internet Protocol (IP) device, the method comprising the steps of:

(A) a circuit switching device sending a packet to an interwork unit, the packet identifying a specific packet switching point at which a loopback is to be effected,

(B) the interwork unit routing the packet to a pre-established loopback path through the packet switching component; and

(C) the interwork unit returning the circuit switched data to the circuit switching device.

5. The method of claim 4 wherein step (A) comprises:

(A1) the circuit switching device sending an Internet protocol packet in which an egress port for a looparound is included, the looparound point being determined by an incoming facility address and a channel number included within the packet.

6. The method of claim 5 further comprising the step of:

(D) the interwork unit setting an entry in a routing table with the incoming facility address and channel number as a looparound address.

7. The method of claim 6 wherein the interwork unit'"'"'s routing table entry is an internal entry.

8. The method of claim 7 wherein the interwork unit removes the routing table entry after at timeout.

9. The method of claim 8 wherein the interwork unit swaps source and destination addresses in the Internet protocol packet it receives from the circuit switching device in step (A1).

10. The method of claim 9 wherein the interwork unit enters an echo response in a packet it returns to the circuit switching side if the looparound the circuit switching component operates.

11. The method of claim 5 wherein the interwork unit swaps source and destination addresses in the Internet protocol packet it receives from the circuit switching device in step (A1).

12. The method of claim 11 wherein the interwork unit enters an echo response in a packet it returns to the circuit switching side if the looparound the circuit switching component operates.

13. The method of claim 5 wherein the interwork unit swaps source and destination address in the Internet protocol packet it receives from the circuit switching device in step (A1).

14. The method of claim 4 wherein the circuit switching device employs time division multiplexing (TDM) and the packet switching component employs asynchronous transfer mode (ATM) packet switching.

15. The method of claim 4 wherein the interwork unit enters an echo response in a packet it returns to the circuit switching side if the looparound the circuit switching component operates.

16. A telecommunications system comprising:

a circuit switching component for initiating a loopback test that encompasses a communications path through a packet switching component; and

a packet switching component responsive to the reception of a test message from the circuit switching component by returning the test message to the circuit switching component, the circuit switching component responsive to the reception of the returned test message by determining that the path encompassed by the packet switching component is operational;

wherein the circuit switching component employs time division multiplexing (TDM) and the packet switching component employs asynchronous transfer mode (ATM) packet switching.

17. A telecommunications system comprising:

a circuit switching component;

a packet switching component; and

an interwork unit connecting the packet switching and circuit switching components, the interwork unit being an Internet Protocol (IP) device, the circuit switching component being configured to send a packet to the interwork unit, the packet identifying a specific packet switching point at which a loopback is to be effected, the interwork unit being responsive to the reception of such a packet from the circuit switching component by routing the packet to a pre-established loopback path through the packet switching component the racket switching component being responsive to reception of such a packet from the interwork unit by routing the packet via the pre-established loopback path to the interwork unit;

wherein the interwork unit is responsive to the reception of the packet from the packet switching component by returning the packet to the circuit switching component.

18. A method of testing telecommunications systems that include both circuit switching and packet switching components, and an interwork unit between the circuit switching and packet switching components, the interwork unit providing an Internet Protocol Device Control (IPDC) and an asynchronous transfer mode Switched Virtual Circuit Capability, comprising the steps of:

(A) a circuit switching device using IPDC to communicate with the interwork unit to set up a loopback path to a designated ATM loopback point identified by an E.164 ATM address;

(B) performing a loopback test employing the loopback path established in step (A).

19. A method of testing telecommunications systems that include both circuit switching and packet switching components, and at least one interwork unit connecting packet switching and circuit switching components, the interwork unit being an Internet Protocol (IP) device, the method comprising the steps of:

(A) a circuit switching device sending a packet to an interwork unit, the packet identifying a specific packet switching point at which a loopback is to be effected,

(B) the interwork unit routing the packet to a pre-established loopback path through the packet switching component,

(C) the interwork unit returning the circuit switched data to the circuit switching device, and

(D) the circuit switching device sending an Internet protocol packet in which an egress port for a looparound is included, the looparound point being determined by an incoming facility address and a channel number included within the packet;

wherein the interwork unit swap source and destination addresses in the Internet protocol packet it receives from the circuit switching device in step (D).

20. The method of claim 19 wherein the interwork unit enters an echo response in a packet it returns to the circuit switching side if the looparound the circuit switching component operates.