GB2399981A - Virtual communications assistance for law enforcement act device - Google Patents

Virtual communications assistance for law enforcement act device Download PDF

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Publication number
GB2399981A
GB2399981A GB0319048A GB0319048A GB2399981A GB 2399981 A GB2399981 A GB 2399981A GB 0319048 A GB0319048 A GB 0319048A GB 0319048 A GB0319048 A GB 0319048A GB 2399981 A GB2399981 A GB 2399981A
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GB
United Kingdom
Prior art keywords
network
pri
call
calea
law enforcement
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
GB0319048A
Other versions
GB0319048D0 (en
Inventor
Bizhan Karimi-Cherkandi
Farrokh Mohammadzadeh Kouchri
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Siemens AG
Original Assignee
Siemens AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Siemens AG filed Critical Siemens AG
Publication of GB0319048D0 publication Critical patent/GB0319048D0/en
Priority to US10/809,618 priority Critical patent/US20040219911A1/en
Priority to US10/809,629 priority patent/US20040218731A1/en
Publication of GB2399981A publication Critical patent/GB2399981A/en
Withdrawn legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M3/00—Automatic or semi-automatic exchanges
    • H04M3/22—Arrangements for supervision, monitoring or testing
    • H04M3/2281—Call monitoring, e.g. for law enforcement purposes; Call tracing; Detection or prevention of malicious calls
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M7/00—Arrangements for interconnection between switching centres
    • H04M7/12—Arrangements for interconnection between switching centres for working between exchanges having different types of switching equipment, e.g. power-driven and step by step or decimal and non-decimal
    • H04M7/1205—Arrangements for interconnection between switching centres for working between exchanges having different types of switching equipment, e.g. power-driven and step by step or decimal and non-decimal where the types of switching equipement comprises PSTN/ISDN equipment and switching equipment of networks other than PSTN/ISDN, e.g. Internet Protocol networks
    • H04M7/1245—Arrangements for interconnection between switching centres for working between exchanges having different types of switching equipment, e.g. power-driven and step by step or decimal and non-decimal where the types of switching equipement comprises PSTN/ISDN equipment and switching equipment of networks other than PSTN/ISDN, e.g. Internet Protocol networks where a network other than PSTN/ISDN interconnects two PSTN/ISDN networks
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q11/00—Selecting arrangements for multiplex systems
    • H04Q11/04—Selecting arrangements for multiplex systems for time-division multiplexing
    • H04Q11/0428—Integrated services digital network, i.e. systems for transmission of different types of digitised signals, e.g. speech, data, telecentral, television signals
    • H04Q11/0435—Details
    • H04Q11/0464—Primary rate access circuits
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q3/00—Selecting arrangements
    • H04Q3/0016—Arrangements providing connection between exchanges
    • H04Q3/0029—Provisions for intelligent networking
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q2213/00—Indexing scheme relating to selecting arrangements in general and for multiplex systems
    • H04Q2213/13034—A/D conversion, code compression/expansion
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q2213/00—Indexing scheme relating to selecting arrangements in general and for multiplex systems
    • H04Q2213/13093—Personal computer, PC
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q2213/00—Indexing scheme relating to selecting arrangements in general and for multiplex systems
    • H04Q2213/13205—Primary rate access, PRI
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q2213/00—Indexing scheme relating to selecting arrangements in general and for multiplex systems
    • H04Q2213/13282—Call forward, follow-me, call diversion
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q2213/00—Indexing scheme relating to selecting arrangements in general and for multiplex systems
    • H04Q2213/13372—Intercepting operator
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q2213/00—Indexing scheme relating to selecting arrangements in general and for multiplex systems
    • H04Q2213/13389—LAN, internet

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Computer Security & Cryptography (AREA)
  • Technology Law (AREA)
  • Data Exchanges In Wide-Area Networks (AREA)

Abstract

A law enforcement application 304/324 executes commands for monitoring telephone conversations in compliance with the Communications Assistance for Law Enforcement Act (CALEA). When a CALEA subject 306/326 initiates a call to a destination 308/328, a service control point (SCP) 316 redirects the call to the law enforcement application which uses a Primary Rate Interface (PRI) device 302/322 to handle the call and loop the B-channels associated with the CALEA subject and the destination device. The PRI device respectively redirects D-channel call data and B-channel voice data across a packet network (IP network) to an operator 314/334 and a monitoring device such as a recorder or headset 336. The redirected data is encapsulated in a packet telephony protocol such as Signalling Transport (SIGTRAN) so that it may be transported over the packetized network. The law enforcement application 304/324 may be associated with any network such as a PSTN 308 or IP 320 network. Calls may be initiated over any communications network.

Description

239998 1
TITLE OF THE INVENTION
VIRTUAL COMMUNICATIONS ASSISTANCE FOR LAW ENFORCEMENT ACT
(CALEA) DEVICE
BACKGROUND
Field Of The Invention.
The present invention relates to a Communications Assistance for Law Enforcement Act (CALEA) device and, more particularly, to facilitating an Advanced Intelligent Network (AIN)-CALEA in VoIP network to capture call data and call content using a virtual primary rate interface (PRI) connection.
Related Information.
The purpose of this invention is to provide lawful intercept of calls. In these modern times, it is unfortunate that public communications have become a conduit by which unlawful activities coordinate. The need to address this problem became apparent with the implementation of digital technology and wireless services, which have almost outpaced the ability of law enforcement officials to conduct authorized electronic surveillance.
In order to combat this, the US Congress in 1994 passed the Communications Assistance for Law Enforcement Act (CALEA), which provides that carriers shall implement procedures and equipment to assist law enforcement agencies, primarily the Federal Communications Commission, to carry out their lawful interception and monitoring of telecommunication calls.
Specifically, CALEA requires telecommunications Carriers to ensure that their equipment, facilities, and services are able to comply with authorized electronic surveillance.
From the carrier perspective, the CALEA implementations are burdensome. The entire cost for implementing these! provisions are left up to the Carriers, leaving the carriers holding the bag. Thus, Carriers need to comply with these enforcement provisions with the least amount of cost burden to their overhead.
Moreover, implementing the CALEA provisions for the various types of networks is difficult to say the least. In the packet world, for example, redirecting calls is not a trivial undertaking, especially when one considers that packets are only portions of data calls that are whizzing around the network universe.
It would be an advantage if one could redirect calls within the packet world particularly for CALEA applications. This would allow the CALEA application to be placed anywhere.
What is needed is a CALEA application that is cost effective for carriers to implement. What is further needed is a means by which carriers can redirect packets. It would be advantageous to be able to place the CALEA device anywhere in the network. Heretofore, there has not been provided any such means that resolves these problems.
OBJECTS & SUMMARY OF THE INVENTION l
An object of the present invention is to provide a virtual CALEA device.
An object of the present invention is to provide a virtual PRI facilitating an Advanced Intelligent Network (AIN) that implements CALEA.
Yet another object of the invention is to redirect packets in a packet network.
Still another object of the invention is to place the CALEA device anywhere in the network.
In accordance with the present invention there is provided an apparatus for effecting a governmental regulation for monitoring a call in a telecommunications network. An application for executing commands that effect the governmental regulation. A primary rate interface (PRI) is coupled to the application for redirecting calls to be monitored according to the governmental regulation. A telephony protocol encapsulating the PRI for transporting signals relating to the call over a packetized network.
BRIEF DESCRIPTION OF THE DRAWINGS
The following figures illustrate the present invention in particular detail, and it shall be considered that the figures are merely examples: Figure 1 is a block diagram illustrating SIGTRAN encapsulating PRI; Figure 2 is a block diagram of the protocol stack of the present invention; and Figure 3 is a system diagram of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Figure 1 shows how a typical network 100 with SIGTRAN PRI (Signaling Transport Primary Rate Interface) incorporated therein is modified to include the virtual CALEA device 102 of the present invention.
As shown in the figure, there are a number of PBX (private branch exchange) telephone systems connected through various means, each PBX within an enterprise for switching calls between enterprise users on local lines while allowing all users to share a certain number of external phone lines. The main purpose of this configuration is to save the cost of requiring a line for each user to the telephone company's central office.
There is shown, for example, PBX 102 for connecting the individual users 104 through a media gateway 106 that uses a Primary Rate Interface (PRI) to channel calls through the network100. Similarly, a PBX 108 couples calls from users through a media gateway 112.
A PBX 114 encapsulates PRI using SIGTRAN in the form of customer premises equipment and another media gateway 116.
Similarly, another PBX 118 encapsulates PRI using SIGTRAN and is connected to the network 100 through a media gateway 120.
Media gateway controllers 122, 124 control the media gateways 106, 112, 116 and 120 and exchange the data from the POX networks via a router 126 according to, for example, Integrated Services Digital Network User Part (E-ISUP) signaling.
A brief word regarding SIGTRAN is perhaps in order. SIGTRAN is the standard telephony protocol used to transport Signaling System 7 (SS7) signals over the Internet. SS7! signals consist of special commands for handling a telephone call. Internet telephony uses the Internet Protocol's packet-switched connections to exchange voice, fax, and other forms of information that have traditionally been carried over the dedicated circuit switched connections of the public switched telephone network (PSTN). I Calls transmitted over the Internet travel as packets of data on shared lines, avoiding the tolls of PSTN. A telephone company switch transmits SS7 signals to a signaling gateway.
The gateway, in turn, converts the signals into SIGTRAN packets for transmission over IP to either the next signaling gateway or, if the packet destination is not another PSTN, to a soft switch.
Figure 2 shows the protocol stack 200, a hierarchy of protocols which work together to provide the services on a communications network. The SIGTRAN protocol is made up of several such components. Its protocol stack comprises a standard IP, a common signaling transport protocol (used to ensure that the data required for signaling is delivered properly), such as the Stream Control Transport Protocol (SCTP), and an adaptation protocol that supports "primitives" (a basic interface or segment of code that can be used to build more sophisticated program elements or interfaces) that are required by another protocol.
For this invention, the protocol stack is shown in Figure 2.
A storage service provider (SSP) 202 is the first element On the Internet, a storage service provider (SSP) is a company that provides computer storage space and related management to other companies. The SSP is coupled to the SIGTRAN (SG) component 204 via PRI or Tl/El. In turn, the SO component 204 is coupled to the media gateway controller (MGC) call agent 206 via SIGTRAN or Ethernet. The MGC call agent 206 is coupled to the IP network 208 via SIP or Ethernet.
In Figure 3, there is shown a virtual primary rate interface (PRI) device encapsulated by SIGTRAN for facilitating AIN- CALEA 300. The present invention is advantageous because it allows CALEA applications to interact easily with a packet network, yet while maintaining the Time Division Multiplex (TDM) infrastructure of the resident network. By encapsulating the PRI in a SIGTRAN device, the invention provides a virtual interface by which CALEA application can be implemented in the TDM network. The term "virtual" as opposed to "physical" indicates that the PRI is defined in the TDM-based hard-wired (physical) connection. By encapsulating PRIprotocol (layer 2 & layer 3) in the packet world the physical connection becomes virtual.
PRI is an important protocol for large ISDN users. In comparison with the Basic Rate Interface (BRI), the other ISDN protocol which is intended for personal or small enterprises, PRI is intended for use with high speed connections. In general, both BRI and PRI include a number of B-channels and a D-channel. Each B-Channel carries data, voice, and other services. The D-Channel carries control and signaling information.
However, with PRIs 23 B-channels and one 64 Kpbs D-channel using a T-1 line or 30 B-channels and 1 D-channel using an E1 line, PRI is the hands down winner for commercial applications. For that matter, a Primary Rate Interface user on a T-1 line can have up to 1.544 Mbps service or up to 2.048 Mbps service on an E1 line. The 23 (or 30) B-channels can be used flexibly and reassigned when necessary to meet special needs such as videoconferences. The Primary Rate user may be hooked up directly to the telephone company central office.
The advantage of the PRI access is its capability to be set to carry any calling ID and called ID and the network will accept the delivery of the call. This is different than other access types such as a regular telephone. By carrying any calling ID and called ID, the CALEA subject does not sense the redirection of the call.
As shown in Figure 3, a PRI-Device 302 is provided to assist a CALEA application 304. When the CALEA subject 306 initiates a call, for example, through a network 308 to a destination 310, the call is managed by the PRI device 302.
The network 308 may be any type of network, including A PSTN or IP network. Each call offered to this device uses the B channel 312. That is, the voice is conveyed over the B channel 312 and is captured. The call data is conveyed on the D-channel 314, for example, User-User Information (W I) as supplementary data.
Using the call data, the invention originates a call and loops the BChannel 312 to the destination 310. The call data 314 is forwarded by the PRI device 3 02 to the operator 316 and the voice signal may be forwarded to a remote location (not shown) which may terminate in a terminal, such as a recorder or head set for example.
The network 308 determines whether to forward the call to the CALEA device with the assistance, for example, of a Service Control Point (SCP) 316. The SCP 316 determines how to handle the traffic, i.e., whether to redirect the call to the CALEA device 304, also called a CALEA facility, that provides the CALEA functionality.
The PRI device 302 in one aspect may be a PRI card. The PRI card may be installed in a computer, such as a personal computer (PC), where the CALEA application 304 is running.
Further, the PRI device 302 may be connected through a gateway 318 to another network 320, such as an IP network.
A virtual PRI-Device 322 is further provided to assist a CALEA application 324. When a second CALEA subject 326 initiates a call, for example, through the network 320 to a destination 328, the call is managed by the PRI device 322.
The network 320 may be any type of network, including A PSTN or IP network. Each call offered to this device uses the B channel 330. That is, the voice is conveyed over the B channel 330 and is captured. The call data is conveyed on the D-channel 332, for example, User-User Information (WI) as supplementary data. 9 1
Using the call data, the invention originates a call and loops the BChannel 332 to the destination 328. The call data 334 is forwarded by the PRI device 322 to an operator and the voice signal may be forwarded to a remote location; 336 which may terminate in a terminal, such as a recorder or head set for example.
The network 320 determines whether to forward the call to the CALEA device with the assistance, for example, of a Service Control Point (SCP). The SOP determines how to handle the traffic, i.e., whether to redirect the call to the CALEA device 324, also called a CALEA facility, that provides the CALEA functionality.
The PRI device 322 in one aspect may be a PRI card. The PRI card may be installed in a computer, such as a personal computer (PC), where the CALEA application 324 is running.
Further, the PRI device 322 may be connected through a gateway 318 to another network 308.
In the present invention, the virtual PRI device 322 is composed of an IPInterface encapsulated in a SIGTRAN device 340. The primary rate access (PRI) interface is provided in the TDM world. To move forward to a packet network, we need additional protocol (SIGTRAN) to be able to use a PRI interface inside a packet network. This is illustrated in Figure 1, which shows the role of SIGTRAN is, and how PRI interface is utilized inside the packet network.
The whole sense of having a virtual CALEA device in a packet network is to provide lawful intercept for packet calls without having to leave the packet world. The object of this invention is not necessarily the feature richness of such device, but nevertheless is worth mentioning that realization of such device may ease realization of many features. For example, the benefit of using the virtual CALEA device is depicted in Figure 1. As will be appreciated therefrom, the; CALEA premise could be realized anywhere inside the packet network, where the law enforcement premises LEI-CPE could be located anywhere within the packet world and based on the subject, intercepted data (or call content) can be forwarded to a specific LEI-CPE (e.g a LEI-CPE may be a SIP phone).
While the present invention has been described with reference to a CALEA device, the invention is not limited to a particular ratification of CALEA, and covers assisting law enforcement regulation, either government agency or statutory promulgated, of communications in general.
The invention also relates to a method 200 for establishing a CALEA functionality using a PRI device as shown in Figure 2.
In step 202, the SOP decides whether CALEA is to be applied to the call. In step 204, the invention, applying a PRI device, redirects the voice signal over the B-channel. In step 206, the call data is redirected over the D-Channel and the process ends.
The present invention has, thus, been described with reference to the detailed figures, and it shall be appreciated that the invention is not so limited to the particular aspects or embodiments shown, but encompasses the broader invention contemplated herein.

Claims (12)

WE CLAIM
1. An apparatus for effecting a governmental regulation for monitoring a call in a telecommunications network, ; comprising: an application for executing commands that effect the governmental regulation; 10a primary rate interface (PRI) coupled to the application for redirecting calls to be monitored according to the governmental regulation; and a telephony protocol encapsulating the PRI for transporting signals relating to the call over a packetized; network. -
2. The apparatus of claim 1, wherein the telephony protocol is Signaling Transport SIGTRAN.
3. The apparatus of claim 1, wherein the governmental regulation is established by the Communications Assistance for Law Enforcement Act (CALEA).
4. The apparatus of claim 1, wherein the PRI includes a B- Channel that conveys voice signals and the PRI loops the voice signals to a termination point.
5. The apparatus of claim 1, wherein the PRI includes a D Channel that conveys call data and the PRI forwards the call data to an operator.
6. The apparatus of claim 1, wherein the PRI is a personal computer (PC) card.
7. The apparatus of claim 1, further comprising a Service Control Point that determines whether a particular call is to be regulated.
8. The apparatus of claim 1, wherein the network is a public switched telephone network PSTN.
9. The apparatus of claim 1, wherein network is an Internet Protocol (IP) network.
10. A method for effecting a governmental regulation for monitoring a call in a telecommunications network, comprising the steps of: providing an application that regulates calls in accordance with the governmental regulation; providing a primary rate interface (PRI) for redirecting the calls to be regulated by law enforcement regulation; and transporting signals relating to the call over a packetized network using a transport protocol.
11. The method of claim 10, wherein the step of transporting is based on signaling transport SIGTRAN.
12. The method of claim 10, wherein the governmental regulation is compliant with Communications Assistance Law Enforcement Act.
GB0319048A 2003-03-25 2003-08-14 Virtual communications assistance for law enforcement act device Withdrawn GB2399981A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
US10/809,618 US20040219911A1 (en) 2003-03-25 2004-03-25 Virtual communications assistance for law enforcement act (CALEA) device
US10/809,629 US20040218731A1 (en) 2003-03-25 2004-03-25 Communications assistance for law enforcement act (CALEA) device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US45734703P 2003-03-25 2003-03-25

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Publication Number Publication Date
GB0319048D0 GB0319048D0 (en) 2003-09-17
GB2399981A true GB2399981A (en) 2004-09-29

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GB0319051A Ceased GB0319051D0 (en) 2003-03-25 2003-08-14 Communications assistance for law enforcement act (CALEA) device
GB0319050A Ceased GB0319050D0 (en) 2003-03-25 2003-08-14 Advanced intelligent network (AIN) for assisting communications assistance for law enforcement act (CALEA)
GB0319048A Withdrawn GB2399981A (en) 2003-03-25 2003-08-14 Virtual communications assistance for law enforcement act device

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GB0319051A Ceased GB0319051D0 (en) 2003-03-25 2003-08-14 Communications assistance for law enforcement act (CALEA) device
GB0319050A Ceased GB0319050D0 (en) 2003-03-25 2003-08-14 Advanced intelligent network (AIN) for assisting communications assistance for law enforcement act (CALEA)

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5590171A (en) * 1994-07-07 1996-12-31 Bellsouth Corporation Method and apparatus for communications monitoring
US6078648A (en) * 1998-07-09 2000-06-20 Bell Atlantic Network Services, Inc. Advanced intelligent network (AIN) functionality for electronic surveillance
US6097798A (en) * 1998-07-09 2000-08-01 Bell Atlantic Network Services, Inc. Electronic surveillance in a public switched telephone network
US6229887B1 (en) * 1998-07-09 2001-05-08 Bell Atlantic Network Services, Inc. Advanced intelligent network (AIN) functionality for electronic surveillance
WO2002049329A2 (en) * 2000-12-12 2002-06-20 Nice Systems Ltd. A method and system for monitoring and recording voice from circuit-switched switches via a packet-switched network

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5590171A (en) * 1994-07-07 1996-12-31 Bellsouth Corporation Method and apparatus for communications monitoring
US6078648A (en) * 1998-07-09 2000-06-20 Bell Atlantic Network Services, Inc. Advanced intelligent network (AIN) functionality for electronic surveillance
US6097798A (en) * 1998-07-09 2000-08-01 Bell Atlantic Network Services, Inc. Electronic surveillance in a public switched telephone network
US6229887B1 (en) * 1998-07-09 2001-05-08 Bell Atlantic Network Services, Inc. Advanced intelligent network (AIN) functionality for electronic surveillance
WO2002049329A2 (en) * 2000-12-12 2002-06-20 Nice Systems Ltd. A method and system for monitoring and recording voice from circuit-switched switches via a packet-switched network

Also Published As

Publication number Publication date
GB0319050D0 (en) 2003-09-17
GB0319051D0 (en) 2003-09-17
GB0319048D0 (en) 2003-09-17

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