Error detection/correction and fault detection/recovery – Data processing system error or fault handling – Reliability and availability
Reexamination Certificate
1998-06-09
2001-03-20
Black, Thomas (Department: 2171)
Error detection/correction and fault detection/recovery
Data processing system error or fault handling
Reliability and availability
C379S272000, C379S279000
Reexamination Certificate
active
06205557
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of Invention
The invention relates to redundant call processing. In particular, the invention relates to a method and apparatus for copying call information expeditiously and in a way that allows in-progress call processing to continue if an active call processor fails.
2. Description of Related Art
To assure reliability, redundancy is often built into telecommunications networks. Most network equipment, including call processors and databases, are duplicated to provide greater reliability in the event of equipment failure. For example, active call processors are backed-up by duplicate equipment, referred to as a standby call processor. Call processors are used during the call set-up stage (i.e., the time from call initiation to establishing the call connection) to process information, transmit instructions regarding routing, allocate network resources, approve the call and the billing, and gather further information where needed. If the active call processor fails, the standby call processor can take over to process new incoming calls.
To perform properly, the standby call processor must have the same information that is available to the active call processor. Thus, the standby call processor is periodically updated and the data synchronized with that of the active call processor. Generally, wherever network data is duplicated, it is periodically updated and synchronized. However, periodic updating is a problem when failure occurs between the updates. Thus, new technology is needed to reduce the effects of the failures between the updates.
SUMMARY OF THE INVENTION
This invention provides a redundant call processing system that ensures call processing in the event of a failure of an active call server by maintaining in a standby call server the same information regarding the call as the active call server. In a telecommunications network, an active call server is backed up by a standby call server. The active call server receives an initial signaling message from an interface server to initiate a call. The active call server processes the initial signaling message and generates call information for the call. This information includes, but is not limited to, the content of the signaling message received; registers containing transient data about the call, such as counter and timer values; customer identification; and customer data and logic, for example. The active call server may then send a request back to the interface server requesting more information regarding the call. When the request is sent, the active call server copies the call information and sends the copy to the standby call server.
The interface server periodically determines if the active call server has failed. If the active call server has not failed, the interface server sends subsequent signaling messages to the active call server. However, if the active call server has failed, the interface server sends the subsequent signaling messages to the standby call server. In this way, the telecommunications network can insure, in the event of a failure of the active call server, that calls that have been initiated, but not established, will be established.
REFERENCES:
patent: 5442691 (1995-08-01), Price et al.
patent: 5592530 (1997-01-01), Brockman et al.
patent: 5736933 (1998-04-01), Segal
patent: 5799156 (1998-08-01), Hogan et al.
patent: 5848128 (1998-12-01), Frey
patent: 5875242 (1999-02-01), Glaser et al.
patent: 5896441 (1999-04-01), Akazawa et al.
patent: 5933474 (1999-08-01), Kipp
patent: 5974114 (1999-10-01), Blum et al.
patent: 6016334 (2000-01-01), Kasrai
Chong Koan S.
Dolly Martin C.
Jacob Andrew R.
Johnson Carolyn R.
Lee Won-seok
AT&T Corp.
Black Thomas
Wang Mary
LandOfFree
Redundant call processing does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Redundant call processing, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Redundant call processing will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2445757