Use of multipoint connection services to establish call-tapping points in a switched network

• US 5,754,532 A
• Filed: 11/12/1996
• Issued: 05/19/1998
• Est. Priority Date: 01/09/1995
• Status: Expired due to Term

• Current Assignee: Computer Associates Think Inc. (Broadcom, Inc.)
• Original Assignee: Cabletron Systems Incorporated (Extreme Networks, Inc.)
• Inventors: Matthews, Wallace, Jeffords, Jason, Dev, Roger, Kaikini, Prasan
• Primary Examiner(s): NGUYEN, CHAU T
• Application Number:
  US08/747,456
• Time in Patent Office: 553 Days
• Field of Search: 370/244, 370/250, 370/254, 370/260, 370/265, 370/351, 370/355, 370/395, 370/396, 370/397, 370/408, 370/255, 370/264, 379/202, 379/206
• US Class Current: 370/250
• CPC Class Codes: H04L 12/1877 Measures taken prior to transmission
• CPC Class Codes: H04M 3/2254 in networks
• CPC Class Codes: H04M 3/2281 Call monitoring, e.g. for law enforcement purposes; Call tracing; Detection or prevention of malicious calls
• CPC Class Codes: H04M 7/00 Arrangements for interconnection between switching centres
• CPC Class Codes: H04Q 2213/13174 Data transmission, file transfer
• CPC Class Codes: H04Q 2213/13242 Broadcast, diffusion, multicast, point-to-multipoint (1 : N)
• CPC Class Codes: H04Q 2213/13372 Intercepting operator

Abstract

Method and apparatus for providing a call-tapping point in a switched network with point-to-multipoint functionality. The tapping point is added as an additional destination for data being sent from a source node to a first destination node. The tapping point is also added as a destination for data being sent from the first destination node to the source node. A merge operation is performed for finding and combining common segments of the paths between the source and destination, the source and tapping point, and the destination and tapping point.

Claims

1. A method of providing a merged path from a source node to a plurality of destination nodes in a switched network having connection services which provide a point-to-multipoint connection, the method comprising steps of:

(a) invoking the connection services to provide a first connection path between a source node and a first destination node;

(b) configuring at least one network switch in accordance with the first connection path to form a connection from the source node to the first destination node;

(c) invoking the connection services to provide a second connection path between the source node and a second destination node;

(d) performing a forward merge of the second connection path with the first connection path including the steps of;

determining if a first switch is in common between the first and second connection paths;

if the first switch is in common, merging a first common segment of the first and second connection paths from the source to the first switch;

continuing to determine if a next switch is in common between the first and second connection paths and if so merging a next common segment until the first and second connection paths have diverged;

if the next switch is not in common, determining that the two connection paths have diverged at a first point of divergence and stopping the merge operation; and

(e) configuring at least one network switch in the second connection path from the first point of divergence to the second destination node so as to form a point-to-multipoint connection from the source node to the first and second destination nodes by programming a connection table in the at least one network switch.

2. The method of claim 1, wherein step (e) comprises:

programming the at least one network switch to forward data received on a first inport out to at least two outports.

3. The method of claim 2, wherein step (e) comprises:

modifying an entry in a connection table of the at least one network switch to logically map the first inport to the at least two outports.

4. The method of claim 1, wherein each connection path is selected based on one or more metrics.

5. The method of claim 4, wherein the metrics include cost, speed, network traffic and quality of service.

6. The method of claim 4, wherein each connection path is optimal for one metric and passes a set of threshold tests for other metrics.

7. The method of claim 1, wherein the first common segment is a longest common segment.

8. The method of claim 1, wherein:

the network is a telephone network.

9. The method of claim 1, wherein:

the network is a packet-switched data network.

10. The method of claim 1, wherein:

the network is an asynchronous transfer mode (ATM) network.

11. The method of claim 1, wherein the merged path is used for monitoring the switched network for surveillance.

12. The method of claim 1, wherein the merged path is used for analyzing network problems.

13. The method of claim 1, wherein:

the data includes one or more of voice, video and computer information.

14. A method of providing a merged path from a source node to a plurality of destination nodes in a switched network having connection services which provide a point-to-multipoint connection, the method comprising steps of:

(a) invoking the connection services to determine a first connection path between the source node and a first destination node including network switches in the first connection path in an order from the source node to the first destination node;

(b) invoking the connection services to determine a second connection path between the source node and a second destination node including network switches in the second connection path in an order from the source node to the second destination node;

(c) performing a forward merge of the first and second connection paths, including steps of;

(d) selecting a current network switch from the first connection path in the first order;

(e) determining whether the selected current network switch is in both the first and second connection paths;

(f) when the selected current network switch is in both the first and second connection paths;

configuring the selected current network switch according to the first connection path, identifying the selected current network switch as a previous network switch, selecting a next network switch from the first connection path as the current network switch and repeating step (e);

(g) when the selected current network switch is not in both the first and second connection paths;

configuring the previous network switch so as to form a point-to-multipoint connection from the source node to the first destination node and to the second destination node, configuring unselected network switches in the first path in accordance with the first connection path and configuring unselected network switches in the second connection path according to the second connection path.

15. The method according to claim 14, wherein the step of configuring the selected current network switch within step (f) includes a step of modifying a connection table of the selected current network switch to logically map a first inport to a first outport according to the first connection path.

16. The method according to claim 14, wherein the step of configuring the previous network switch in step (g) includes a step of modifying a connection table of the previous network switch to logically map a first inport to first and second outports.

17. The method as recited in claim 14, wherein step (c) further comprises steps of:

when all network switches in the first connection path are determined to be in the second connection path, configuring a last selected network switch from the first connection path so as to form a point-to-multipoint connection from the source node to the first destination node and to the second destination node.

18. The method as recited in claim 17, wherein the step of configuring the last selected network switch from the first connection path includes a step of modifying a connection table of the last selected network switch to logically map a first inport to first and second outports.