Patent Application
20060146838
This invention generally relates to transmitting communications in networks. More specifically, it relates to routing communications efficiently within these networks.
In telephony networks, calling patterns within the network change over time. For example, some calling routes within the network become overloaded and other routes are seldom used. The addition or deletion of new devices within the network may also cause the calling patterns to change. Routing tables within these networks store and track this type of information for later use. In one example, these tables are used as the basis for routing Session Initiation Protocol (SIP) based Internet Protocol (IP) messages within networks.
Previous systems use routing tables configured to store routing information. This information is entered manually by system administrators into the tables, which are stored on the system. Changes to the routing tables require close coordination between systems and are often performed at low traffic times to prevent network outages when systems are temporarily out of synchronization.
Several problems exist with the use of routing tables within these previous systems. For example, changes to the tables take a long time to propagate through the system resulting in the inefficient transmission of information. In addition, changes are required to be manually made. Because the changes are made manually, the process is labor intensive and costly. Furthermore, data entry errors may occur as the operator enters the information into the system.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions and/or relative positioning of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of various embodiments of the present invention. Also, common but well-understood elements that are useful or necessary in a commercially feasible embodiment are often not depicted in order to facilitate a less obstructed view of these various embodiments of the present invention. It will also be understood that the terms and expressions used herein have the ordinary meaning as is accorded to such terms and expressions with respect to their corresponding respective areas of inquiry and study except where specific meanings have otherwise been set forth herein.
A system and method for automatically routing information through a network uses a routing table, which is automatically updated. When a call is placed from a first communication unit (originator) to a second communication unit (target) in a network, a routing table is updated to show the identity of a “home” server that services the second communication unit (e.g., by providing access to the target subscriber's location information or other pertinent service subscription information). Thereafter, calls to the second communication unit that require applicable location or subscription information are directly routed to the target's home server, and, thereafter, to the second communication unit.
In many of these embodiments, a first message is sent to a first server. Responsively, a redirect message is received from the first server. The redirect message comprises identification of the designated home server associated with a destination mobile unit and a target range. The home server provides access to the target subscriber's location information or other pertinent service subscription information (e.g., via a Home Location Registrar, SIP Registrar, etc.). The target range includes a plurality of communication unit addresses that are likewise associated with the same server. A routing table with the target's home server and associated address range is updated. Subsequently, other messages sent from the first communication unit are sent directly to the target's home server, if applicable location and/or subscription information is not already known.
An update message may also be received from the destination server. The update message comprises information indicating that the target range of the server has changed. A new target range may also be indicated in the message.
Thus, changes to the routing tables are quickly and automatically made and result in the efficient transmission of information. Because the changes are made automatically, errors in the tables are reduced and the cost of operating the system is reduced. The changes are propagated automatically through the network and require no subsequent human interaction.
Referring now to
A plurality of destination servers is also coupled to the network 104. The servers include server 106, 108, 110, and 112. Each of the servers 106, 108, 110, and 112, supports a range of communication unit addresses or a plurality of such address ranges. Each of the servers 106, 108, 110, and 112 acts as a home server for the associated communication units. For example, server 106 serves as the home server for communication units in the range TA1 to TA2. Server 108 serves communication units in the range TB1 to TB2. Server 110 serves communication units in the range TC1 to TC2. Finally, server 112 serves communication units in the range TX to TY.
The network 104 may be a wide area network (WAN) or other suitable network. For example, the network 104 may be a wireless network, a telephony network, or some combination of these networks. In addition, the various components that comprise the network 104 and that are needed to route information between two points in the network are not shown or described since these elements are well known in the art. For example, elements such as routers, servers, and controllers that route information through the network 104 are omitted.
In operation, the table 103 at the server 102 is updated with target range information automatically without the need for human intervention. For example, an initial message may be sent from the server 102 to one of the servers 106, 108, 110, or 112. The server 106, 108, 110, or 112 returns a redirect message to direct the server 102 to send the initial message to the proper server having the proper address range associated with the destination communication unit. In one example, the initial message may be a Session Initiation Protocol (SIP) Invite message. Other examples of messages that conform to other protocols are possible.
Thereafter, messages directed to the destination communication unit, or any other communication unit in the associated address range, will be sent directly to the proper server without the need of going through an intermediate server. Thus, the redirect message will not need to be sent and processed and the time needed to make connections between a source communication unit and a destination communication unit decreases.
Changes in the target ranges at the servers 106, 108, 110, and 112 may also be made automatically to the table 103 at the server 102. For instance, the servers 106, 108, 110, or 112 may send an update message to the server 102. The update message indicates that the target range for the identified server has changed and identifies that the new range of communication unit addresses served by the server 106, 108, 110, or 112. Thus, when a subsequent call is attempted to be made to a communication unit and the communication unit is no longer served by the server, a futile attempt to connect to that server is not made and the message is automatically routed to the appropriate home server.
Referring now to
The server 102 selects a server to receive the Invite message. The selection may be a random selection (of any server), a best guess of a target server based upon certain criteria that the server 102 has gathered, or may use what proves to be incorrect information stored in the table 103. In the case illustrated in
The message 114 is routed through the network 104 using conventional routing techniques over a communication link 116. The server 106 receives the message 114 and analyzes the message. The server 106 discovers that the message is addressed to the communication unit 119. However, the server 106 determines that it is not the designated home server for the target communication unit 119. Consequently, the server 106 sends a redirect message 118 to the server 102. The redirect message 118 returned to the server 102 includes the identity of the proper server 112 that should service the message 114 and the range of communication unit addresses that are similarly serviced by the server 112.
The redirect message 118 is sent to the server 102 via the network 104. The server 102 receives the redirect message 118. Consequently, the server 102 sends a second invite message 120 to the server 112 via the network 104 via a communication link 112. Also, the table 103 is updated in the server 102 to reflect the information received. As detailed below, subsequent calls to the communication unit 119 or other communication units in the range and being serviced by the server 112 are directly made to the server 112 and have no need to be processed by an intermediate server.
In this case, the second Invite message 120 is received at the server 112. The server 112 processes the Invite message and determines the applicable information regarding the target's communication unit (e.g., target location and destination call server). The connection between the first communication unit 101 and the second communication unit 119 is then established using standard call routing techniques, possibly involving another call server (e.g., if the target is currently roaming outside their home network service area).
Referring now to
In this case, the table 103 has a listing of the range TX to TY with the identity of the communication unit 119 falling within this range. Because the table 103 contains an entry identifying that the communication unit 119 is associated with the server 112, a direct connection can be made to the server 119 without the need of using an intermediate server. In this case, a connection 126 is used to transmit an Invite message 124 from the originating server 102 and the destination communication unit's 119 home server 112 via the network 104. The server 112 receives the message 124, determines the applicable information regarding the target's communication unit and establishes the call to communication unit 119 using standard call routing techniques, possibly involving another call server (e.g., if the target is currently roaming outside their home network service area). In other words, the message 124 does not have to be processed by the server 106 before being sent to the correct home server 112.
Calls made to other communication units served by the server 112 and indicated in the table 103 may also be made without the use of intermediate servers such as server 106. For example, a third communication unit 127 may also be within the range of communication unit addresses serviced by the server 112. In this case, a call may be made directly from the communication unit 101, or any other communication unit that is serviced by server 102, to the communication unit 127 via the network 104 and servers 102 and 112 without the usage or intervention of an intermediate server. Although shown as a mobile unit, it will be understood that communication unit 127 may be any type of communication device.
Changes in a supported target range at the server 112 are also made automatically to the table 103 at the server 102. The server 112 sends an update message 130 to the server 102. The update message 130 indicates that a target range for the server 112 has changed and identifies a new range of communication unit addresses served by the server 112. Thus, when a subsequent call is attempted to be made to a communication unit and the communication unit is no longer served by the server 112, a futile attempt to connect to the server 112 is not made and the connection can be made to the target communication unit via the correct server.
Referring now to
Referring now to
The message may be, for instance, a Session Initiation Protocol (SIP) Invite message. The controller 506 may send the message to the destination communication unit via a destination server corresponding to the destination server identifier. The controller 506 may also directly send a second message to a destination communication unit via the destination server. An update message may be received and the routing table 510 may be updated based upon information in the update message.
Thus, changes to the routing tables are quickly and automatically made and result in the efficient transmission of information. Because the changes are made automatically rather than manually, errors in the tables are reduced and the cost of operating the system is reduced. The changes are also propagated automatically through the network and need no human interaction.
Those skilled in the art will recognize that a wide variety of modifications, alterations, and combinations can be made with respect to the above described embodiments without departing from the spirit and scope of the invention, and that such modifications, alterations, and combinations are to be viewed as being within the ambit of the inventive concept.
