Abstract:
A traffic monitor listens passively on the data link used to communicate among switching systems for setting up telephone calls for call setup messages and checks the call setup messages for destination telephone number. If it determines that the destination telephone number is for an Internet service provider (ISP), the system reports the point code of the originating office. By analyzing the output of the traffic monitor according to this invention, local exchange carrier (LEC) may reconfigure its network to remove feature rich switches from the ISP call delivery network and replace them with a small tandem-like switch.

Description:
FIELD OF THE INVENTION 
     This invention relates to the area of telephone switching networks and, more specifically, to a system and method for detecting traffic congestion on network trunks caused by, for example, Internet service provider connections to local switching systems. 
     BACKGROUND OF THE INVENTION 
     Home and business data communication has expanded exponentially in recent years. Most businesses and many homes have at least one computer equipped to communicate electronically (i.e., via the Internet, private data network, etc.). Some large businesses (and even some homes) are connected to the data network directly. However, most home applications and small businesses are connected to the data network by some form of Internet service provider (ISP). For each such data connection, there is a modem at the customer&#39;s PC connected to a modem at the Internet service provider&#39;s data access center. Thus, the first leg of the data connect, the leg between the computer and the ISP, is through the existing wireline telephone network. 
     Data access through the telephone network may take one of two forms either through a modem (which is currently at 53 kbps maximum) or through integrated services digital network (ISDN) (which is approximately 128 kbps). For each connection to an Internet service provider, a telephone call is placed from the user&#39;s telephone line to the switch on which the user is based, and then through the telephone network to the switch connected to the Internet service provider. Finally the call is delivered to a modem pool at the Internet service provider equipment via trunks. 
     Local exchange carriers (local telephone companies) in the past have been purchasing switches and provisioning their networks for feature rich voice service. Each switch includes services and features that provide added sources of revenue for the service providers but also cost more than a basic switching system. These switches, however, are being used to connect to ISPs, and these lines are being held longer than ever before. A typical telephone call in the past was approximately two minutes. These days, it is not unusual to have a multi-hour connection. It would greatly benefit the local service providers to connect these data calls through equipment that is not feature rich and save feature rich equipment for telephone service for which they were originally intended. However, there is no current system or method for differentiating between a plain old telephone call and a data call to an ISP, and thus no satisfactory method for the LEC to determine economically rational trunking (inter-office connections). 
     SUMMARY OF THE INVENTION 
     This problem is solved and a technical advance is achieved in the art by a system and method for operating the system that may be connected to a switching system that supports an ISP connection to determine the originating switch of calls to the ISP. The system listens passively on the data link that the signaling network uses to set up telephone calls. The monitor checks call setup messages for destination telephone numbers. If it determines that the destination telephone number is for an ISP, the system reports the point code of the originating office (also found in the call setup message). 
     By analyzing the output of the traffic monitor according to this invention, a local exchange carrier (LEC) may reconfigure its network to remove feature rich switches from the ISP call delivery network and replace them with a small, tandem-like switch. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A more complete understanding of the invention may be obtained from consideration of the following description taken in conjunction with the drawings in which: 
     FIG. 1 is a block diagram of a current local exchange carrier network in which a traffic monitor according to an exemplary embodiment of this invention may be used; 
     FIG. 2 is a block diagram of the connection of the traffic monitor into a switch of FIG. 1; 
     FIG. 3 is an example of a traffic monitor count from the traffic monitor of FIG. 2; 
     FIG. 4 is a flowchart of the operation of the traffic monitor according to this invention; and 
     FIG. 5 is an exemplary reconnection of the network after analysis with the traffic monitor according to an exemplary embodiment of this invention. 
    
    
     DETAILED DESCRIPTION 
     FIG. 1 is a block diagram of a typical local exchange carrier (LEC) system  10  serving a community. In this local network  10 , there are a plurality of switches of local switching systems represented by switches  12 ,  13 ,  14  and  15 . A tandem switch  16  is also present. As is known in the art, tandem switch  16  acts as a hub in a switching network to interconnects other switches to each other and to for example, one of the plurality of long distance networks (not shown, but well known in the art). Switches and tandem switch  12 - 16  are interconnected via trunks  20 . Trunks may comprise, for example, one or more T 1  connections. The full interconnection of switches  12 - 16  are not shown but is well known in the art. In this exemplary embodiment, switch  15  is connected via one or more trunks  20  to an Internet service provider access point  22 . Internet service provider access provides a plurality of modems in communication with modems in the network that prepare the data for connection to the data network  24 . Data network  24  may comprise, for example, the Internet or a private data network as is known in the art. 
     Each switch  12 - 15  is connected to a plurality of telephones represented by telephones  30 . Each telephone  30  has its own set of features according to the needs of the user. For example, if the user is a business, it may have features such as voice mail, caller ID, call forwarding, multiline hunt group, etc. Also connected to switches  12 - 15  are a plurality of PCs  32 . Each PC is connected to switch  12 - 15  by way of a modem  34  as is known in the art. 
     Each switch is connected to a signaling network, which includes signal transfer point  40 , via a separate signaling line  42 . Signaling network and signaling transfer point  40  facilitate the communication of switches among each other in order to, for example, set up and tear down telephone calls. 
     A typical data connection starts with an EPC  32  causing its modem  34  to dial the directory number one of the plurality of directory numbers of Internet service provider access  22 . An origination message is sent over one of the signaling at work connections  40  to signal transfer point  40  which then sends a message to switch  15 . Switch  15  determines that there is an open trunk  20  to by ISP access  22  and sends a message back through STP  40  to the originating switch. A connection is then made between the switch (or tandem) and switch  15  via trunk and then a trunk connection is also made between switch  15  and ISP  20 . 
     As stated above, switch  15  is a feature-rich switch such as a 5ESS® switch manufactured by Lucent Technologies, the assignee of this invention. Each trunk  20  connected between switch  15  and Internet access service provider  22  is a system resource that is not available for other, more lucrative use. Each trunk  20  between switch  15  and ISP  22  is more expensive because of the lack of use of the resources available in switch  15  and the length of time that a typical data call over trunks  20  between switch  15  and ISP  22  will last. 
     Therefore, according to this invention, a traffic monitor  50  as will be described more fully in connection with FIG. 2, is connected to switch  15  along signaling path  42  in order to intercept signaling messages. In general, traffic monitor  50  is passively connected to a signaling path to monitor signaling messages, specifically signaling messages to switch  15 . Traffic monitor  50  monitors call origination messages and listens for (“traps on”) messages that contain a dialed number corresponding to one or more ISP access numbers. When an ISP access number is identified, the source office point code is recorded. The system is considered passive in that it just monitors the connection without invasively affecting call setup time. 
     Turning now to FIG. 2, a block diagram of the connection of traffic monitor  50  to switch  15  is shown. In switch  15 , a modem  200  is connected via a line  42  to STP  40 . Modem  200  uses V.35 protocol to communicate to an interface  202  to the switch also using V.35 protocol. 
     The modem  200  in interface  202  is connected via bus  204 . Bus  204  is tapped by bus  206 . This tap may be, for example, a Y connector as is known in the art. Bus  206  is connected to traffic monitor  50  at an RS  232  port. Traffic monitor  50  may be a programmed personal computer or workstation. Traffic monitor  50  includes a processor  208  for executing instructions and processing data from memory  210 . 
     Turning now to FIG. 3, a typical record is shown. A directory number to trap on is entered into the traffic monitor  50  and into record  300 . Each time an origination message is received for that DN the office point code (OPC) is noted and a peg count (PC) is incremented. If an office point code is not found in the list, then it is added, as will be discussed further, below. 
     Turning now to FIG. 4, a flowchart of the operation of traffic monitor  15  is shown. Processing starts at oval  400  and proceeds to decision diamond  402 . In decision diamond  402 , a determination is made if an origination message has been received. If an origination message has not been received then the message is ignored in oval  400  and processing loops back to decision diamond  402 . 
     If, in decision diamond  402 , an origination message is received then in decision diamond  406  a determination is made if the directory number is equal to one of the ISP directory numbers that are to be trapped on. If the origination message directory number is not the same as an ISP directory number then processing proceeds to oval  408  where the message is ignored and processing loops back to decision diamond  402 . 
     If, in decision diamond  406 , the directory number is one that is of the ISP then processing proceeds to decision diamond  410  where a determination is made if the office point code is in the list. If the office point code is not in the list then processing proceeds to box  412  where the office point code is added to the list. Processing from both decision diamond  410  and action blocks  412  proceeds to action block  416  where the pay count is incremented for the office point code in the message. Processing then loops back to decision diamond  402 . 
     Turning now to FIG. 5, a block diagram of the local telephone network wherein a traffic monitor according to an exemplary embodiment of this invention has been employed is shown. In this exemplary embodiment, the ISP  22  has been moved from switch  15  to a small tandem  500 . Switches  12 ,  14  and tandem  16  (through which switch  13  communicates) have all be retrunked to small tandem  500 . In this exemplary embodiment, small tandem is a 5ESS® switch equipped solely with trunk units. Switch  15  is connected to the public switched telephone network  500 , as is known in the art. In this manner, the cost of a feature rich switch can be avoided lowering the per trunk cost for providing Internet service. 
     It is to be understood that the above-described embodiment is merely an illustrative principle of the invention and that many variations may be devised by those skilled in the art without departing from the scope of the invention. It is, therefore, intended that such variations be included within the scope of the claims.