Electrical computers and digital processing systems: multicomput – Computer-to-computer data routing
Reexamination Certificate
1998-03-31
2002-04-16
Vu, Viet D. (Department: 2154)
Electrical computers and digital processing systems: multicomput
Computer-to-computer data routing
C709S225000, C709S241000, C370S389000, C370S401000, C379S220010
Reexamination Certificate
active
06374302
ABSTRACT:
FIELD OF THE INVENTION
The invention relates to communication networks. More particularly, the invention relates to an action control point master gatekeeper for use in a communications network.
BACKGROUND OF THE INVENTION
A communications network can transmit packets of digital information between computers using a protocol, such as Internet Protocol (IP). An increasingly popular use of IP is to transmit audio, video and other multimedia communications between people. For example, a person can use an IP terminal, such as a personal computer connected to an IP network, to speak with another person with an IP terminal. The use of IP terminals to transmit voice communications, similar to the use of a standard telephone, is called IP telephony. As IP networks and IP terminals become faster and more powerful, the use of IP telephony is expected to dramatically increase.
A set of procedures, known as “H.323,” are being developed to provide a foundation for audio, video and data communications over IP based networks. The H.323 procedures, such as those dated May 1996, are an umbrella recommendation from the International Telecommunications Union (ITU) to describe terminals, equipment and services for multimedia communication over a Local Area Network (LAN) that does not provide a guaranteed quality of service. Such networks are important because they are commonly used in offices, and include packet-switched Transmission Control Protocol/Internet Protocol (TCP/IP) and Internetwork Packet Exchange (IPX) over Ethernet systems.
FIG. 1
illustrates a communications system, or “zone,”
100
according to known H.323 procedures. The zone
100
includes a number of “terminals”
110
, such as personal computers equipped with microphones and speakers, that provide for real-time, two-way communications with another terminal
110
. Each terminal
110
is associated with a terminal address, such as an IP address, which is used to address communications to that terminal
110
. According to H.323 procedures, a terminal
110
must provide audio capability, and may also provide video and/or data capabilities, if desired. The terminals
110
communicate with other entities in the zone
100
over a communications network, such as an IP network. The IP network would typically connect, for example, several terminals
110
in a single office.
The zone
100
may include one or more “gateways”
120
,
130
which provide real-time, two-way communications between terminals
110
in the zone
100
and the Public Switched Telephone Network (PSTN). The gateways
120
,
130
can also communicate, for example, with another gateway to provide IP telephony with terminals located in another zone (not shown in FIG.
1
).
A “gatekeeper”
140
provides address translation, control access and, if desired, bandwidth management in the IP network for other H.323 entities in the zone
100
. Suppose, for example, a person using a terminal
110
in the zone
100
wants to establish an IP telephony call to a co-worker who also has a terminal in the same zone. The person enters the co-worker's “terminal alias” using the terminal
110
, and the terminal alias is sent to the gatekeeper
140
. The terminal alias could be, for example, the co-worker's name, title, telephone number, e-mail address or Web page. The gatekeeper
140
translates the terminal alias into a terminal address, such as an IP address, associated with the co-worker's terminal so that the IP telephony call can be established.
As shown in
FIG. 1
, the zone
100
can include several IP segments that communicate using routers
150
. The zone can also include a “Multipoint Control Unit” (MCU)
160
which enables three or more terminals
110
and gateways
120
,
130
to participate in a multipoint conference. As used herein, the general term “H.323 entity” refers to any H.323 component, such as, for example, a terminal
110
, a gateway
120
,
130
, a gatekeeper
140
or an MCU
160
. The zone
100
is the collection of H.323 entities and must include at least one terminal
110
.
There are several problems with the use of H.323 procedures for IP telephony. One problem is that the procedures cannot be easily “scaled,” or applied to larger systems. For example, the gatekeeper
140
must provide address translation for each terminal
110
in the zone
100
. If, however, a person wants to contact someone in a different zone, there is no easy way to do this when a large number of users are involved. A person may want to contact one of hundreds of thousands, or millions, of other people using a terminal alias. It is not feasible to have a single gatekeeper
140
translate a terminal alias for that many users. The amount of information that would have to be stored is extremely large, and searching the information would be very time consuming. Moreover, databases for every gatekeeper in every zone would need to be constantly updated when any terminal alias or terminal address, in any zone, was changed. The maintenance and synchronization required for such a task is not practical.
Another disadvantage with the use of H.323 procedures is communications service features associated with traditional telephone service, such as the features provided by a global virtual network service, cannot be provided to IP telephony users. For example, a business may want to prevent some users from placing a telephone call outside of a “virtual” private network, which can include a number of different zones. In the traditional circuit switched network, such a call would be considered an “off network” call.
Suppose a company has offices in New York and Washington, each being supported by a different H.323 zone. The company may want to let an employee in the Washington office call other employees in the Washington office and other employees in the New York office. The gatekeeper for the Washington office, however, would not normally know the terminal alias and terminal address of each employee in the New York office. The problem obviously becomes more acute as more employees, offices and zones are added.
Other communications service features that businesses will expect include, for example, associating a password or client number with a telephone call, voice mail, and the use of calling cards. In addition to businesses, consumers have come to expect such communications service features. Moreover, an IP network carrier will need to be able to introduce new features rapidly to a large number of customers.
Still another drawback with the use of H.323 procedures for IP telephony is that only one gatekeeper
140
is present in each zone
100
. If the gatekeeper
140
becomes unavailable, such as, for example, when the computer breaks down, communications in that zone
100
will come to a halt. This will make IP telephony unreliable.
In view of the foregoing, it can be appreciated that a substantial need exists for a method and apparatus allowing for a scalable, reliable and flexible IP telephony system, and for solving the other problems discussed above.
SUMMARY OF THE INVENTION
The disadvantages of the art are alleviated to a great extent by an action control point master gatekeeper. In one embodiment of the present invention, an action control point is used in a communications network that has a gatekeeper able to generate an address inquiry, including a terminal alias. The action control point has a customer database that associates the terminal alias with a terminal address. The action control point also has a master gatekeeper that receives the address inquiry and generates an address reply, including the terminal address, based on the association in said customer database.
In this way, the action control point master gatekeeper acts as the glue between zone gatekeepers. A zone gatekeeper will query to the action control point master gatekeeper for address resolution. The action control point can include a centralized database that associates a terminal alias with a terminal address. The master gatekeeper receives the query, with a terminal alias that needs address resolution, fr
Galasso Linda D.
Hope Edward M.
Jones Michael B.
Ramamurthy Ram S.
AT&T Corp.
Vu Viet D.
LandOfFree
Method and system to provide an action control point master... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and system to provide an action control point master..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and system to provide an action control point master... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2819183