Ring network implemented by telephony switches and links
View Patent ↗A system for using an under-utilized data channel for carrying additional data, in a network mode. One such channel is the D-channel in the ISDN system. In one implementation, a group of telephone call centers share data, using the D-channel, about the lengths of time incoming callers must wait before being answered. Using the shared data, the call centers collectively route incoming calls to call centers having smaller waiting times.
1. In a telephone network comprising a plurality of telephone switching systems each having a processor and interconnected by a plurality of telephone links for transporting telecommunications calls and call-associated signaling between the switching systems, the improvement comprising:
each switching system having information-receiving-means connected to the processor and to a first one of the telephone links leading to a second switching system and information-transmitting means connected to the processor and to a second one of the telephone links different from the first link and leading to a third switching system different from the second switching system, such that all of the switching systems are connected together in a ring by the links each one of which is connected to a receiving means at one of the switching systems and to a transmitting means at another of the switching systems;
each information-transmitting means responsive to receipt of non-call associated information from the processor of its switching system by transmitting the non-call associated information on its connected link accompanied by an identifier of one of the switching systems, and further responsive to receipt of non-call associated information from the information-receiving means of its switching system by transmitting the information on its connected link; and
each information-receiving means responsive to receipt on its connected link of non-call associated information accompanied by an identifier of its switching system by transferring the information to the processor of its switching system, and further responsive to receipt on it connected link of non-call-associated information not accompanied by an identifier of its switching system by transferring the information to the information-transmitting means of its switching system.
2. An individual telephone switching system for use in a telephone network comprising a plurality of telephone switching systems interconnected by a plurality of telephone links for transporting telecommunications calls and call-associated signaling between the switching systems, the individual telephone switching system comprising:
a processor;
information-receiving means connected to the processor and for connection to a first one of the telephone links leading to a second switching system of the telephone network;
information-transmitting means connected to the processor and for connection to a second one of the telephone links different from the first link and leading to a third switching system of the telephone network different from the second switching system;
so as to enable all of the switching systems in the telephone network to be connected together in a ring by the links each one of which connects to an information-receiving means like the information-receiving means of the individual switching system at one of the switching systems and to an information-transmitting means like the information-transmitting means of the individual switching system at another of the switching systems;
the information-transmitting means responsive to receipt of non-call associated information from the processor for transmitting the non-call associated information or its connected link accompanied by an identifier of one of the switching systems, and further responsive to receipt of non-call associated information from the information-receiving means for transmitting the information on its connected link; and
the information-receiving means responsive to receipt on its connected link of non-call associated information accompanied by an identified of its switching system for transferring the information to the processor, and further responsive to receipt on its connected link of non-call-associated information not accompanied by an identified of its switching system for transferring the information to the information-transmitting means.
3. A method of operating a group of ISDN-type data links, comprising the following steps:
a) linking a group of stations together, in a ring-network topography, using D-channels of the links; and
b) transmitting data from an originating station, through all other stations, and back to the originating station, using the ring-network, wherein the data contains routing parameters, which are
i) stored at each station after receipt, and
ii) used by each station in routing telephone calls.
4. Method according to claim 3 , wherein the routing parameters comprise an estimated wait time, EWT, for each station.
5. Method according to claim 3 , and further comprising the steps of
c) accepting a call at a station;
d) routing the call, based on a destination chosen using the routing parameters.
6. A method of operating a telephone system which includes ISDN links, comprising the following steps:
a) using idle D-channels of the ISDN links, maintaining a ring-type network among nodes;
b) maintaining a status table at each node, which contains information which facilitates routing of calls to other nodes; and
c) transmitting data on the ring-type network which updates the status tables.
7. Method according to claim 6 , and further comprising the steps of:
d) receiving an incoming call at a node;
e) examining a status table and identifying a node to which to route the incoming call; and
f) routing the incoming call to the node identified.